The document describes a study that formulated and evaluated polymeric nanoparticles containing the antiviral drug acyclovir for prolonged retention in the stomach. Nanoparticles were prepared using different hydrophilic polymers including bovine serum albumin, chitosan, and gelatin. The nanoparticles were characterized for properties such as particle size, zeta potential, drug loading efficiency, and drug release. Nanoparticles prepared with chitosan in a 1:1 ratio with acyclovir showed a particle size of 312.04 nm, zeta potential of 33.2 mV, drug loading efficiency of 17.54%, and entrapment efficiency of 73.4%, indicating they may be suitable for gastric retention delivery of acyclovir.
Design, Development, Evaluation and Optimization of Microballoons of TelmisartanSnehal Patel
Abstract: In present study an attempt was made to prepare microballoons of
Telmisartan by emulsion solvent diffusion technique for sustained delivery by
using polymers like Ethyl cellulose to extend the drug release for about 12 hours in
the upper GIT, which may result in enhanced absorption and there by improved
bioavailability. Formulation optimization of Telmisartan loaded microballoons was
carried out by using different concentration of Polyvinyl alcohol (PVA) and Ethyl
cellulose. Total 9 batches were formulated. All 9 batches were evaluated for
entrapment efficiency (EE) and buoyancy. Among all batches DP4 shows
maximum entrapment efficiency (EE) and buoyancy and was considered as
optimized formulation. DP4 batch was further used for process optimization. The
process optimization was carried out at three different stirring speeds i.e. 1300,
1500 and 1700 rpm for three different stirring time period i.e. 1hr, 2hr and 3 hr and
another 9 batches were formulated. Out of all the batches DP13 showed the
spherical shape of microballoons without formation of flakes. Optimized batch
DP13 was evaluated for Zeta Potential, Particle Size Distribution which show -
41.8mV and 1.344 μm particle size, SEM, XRD Analysis. Batch DP13 was
charged for stability and were placed in glass vials container and stored at ICH
storage condition (2°C - 4°C Refrigeration condition , 30 ± 2°C / 60% ± 5% RH ,
40 ± 2°C / 75% ± 5% RH ) for a period of 30 days. The samples were analyzed for
physical appearance, buoyancy and for the drug release after 30 days. After 1
months samples were withdrawn and microballoons showed no change in physical
appearances, buoyancy and drug release, which indicate that the microballoons
were stable.
Keywords: Telmisartan, Microballoons, Emulsion solvent diffusion technique,
Buoyancy, Entrapment Efficiency.
DESIGN AND ASSESSMENT OF COLON SPECIFIC DRUG DELIVERY OF CELECOXIB USING PU...Lakshmi
The document summarizes the design and assessment of a colon-specific drug delivery system for celecoxib using pulsincap technique. Celecoxib microcrystals were prepared using a rapid solvent change method and evaluated. The microcrystals were then used to prepare pulsincaps containing hydrogel plugs to provide a lag time before drug release. In vitro drug release studies were conducted on the pulsincaps to assess their ability to deliver celecoxib in a pulsatile manner to the colon. The aim was to improve solubility, target delivery to the colon, and minimize dosing frequency for the treatment of rheumatoid arthritis.
Biopharmaceutical system , methods of permeability , generic biologics, gener...Siddhapura Pratik
Biopharmaceutical classification system, methods of permeability, generic biologics ( biosimilar drug product), clinical significance of bioequivalence studies , special concerns in bioavailability and bioequivalence studies , Generic substitution
This document provides information on a presentation about pharmaceutical approaches to colon targeted drug delivery systems for treating diseases like Crohn's disease. It discusses the anatomy and physiology of the colon, diseases associated with the colon, drug absorption in the colon, and various approaches for colon targeted drug delivery including pH sensitive polymers, time controlled release systems, microbiologically triggered systems, and new approaches like pressure controlled, pulsatile, and multi particulate systems. The presentation aims to highlight the advantages and limitations of different colon targeted drug delivery approaches.
The document discusses colon targeted drug delivery systems. It begins by defining colon targeted drug delivery as targeting drugs to the lower parts of the GI tract, mainly the large intestine. This is done for various objectives like reducing dosing frequency or delivering drugs that would otherwise be degraded. Approaches to colon targeting include pH sensitive coatings, microbially triggered systems, and timed release. Evaluation methods include in vitro dissolution tests and studies using animal models. Key advantages are site specific delivery and protecting drugs from degradation, while challenges include multiple manufacturing steps and drug binding in the colon.
colon drug delivery- advantage and disadvantage of colon delivery, anatomy of colon in healthy and diseased state , different approaches (conventional and new) for colon delivery, in vitro and in vivo evaluation
Colon-specific drug delivery (CDDS) aims to target drug release and absorption in the colon for local treatment of colonic diseases or systemic delivery of proteins and peptides. The document discusses the anatomy and physiology of the colon, factors governing colonic drug delivery, and various pharmaceutical approaches for CDDS including pH-sensitive systems, microbially triggered systems, and timed or controlled release platforms. Evaluation methods for CDDS include in vitro drug release tests under simulated gastric and intestinal conditions and in vitro enzymatic degradation assays.
Theoretical background on GastroPlus Simulation SoftwareArpitha Aarushi
this slides tells about Theoretical background on GastroPlus Simulation Software, basic ACAT model, and schematic diagram of compartment and sub compartment model.
Design, Development, Evaluation and Optimization of Microballoons of TelmisartanSnehal Patel
Abstract: In present study an attempt was made to prepare microballoons of
Telmisartan by emulsion solvent diffusion technique for sustained delivery by
using polymers like Ethyl cellulose to extend the drug release for about 12 hours in
the upper GIT, which may result in enhanced absorption and there by improved
bioavailability. Formulation optimization of Telmisartan loaded microballoons was
carried out by using different concentration of Polyvinyl alcohol (PVA) and Ethyl
cellulose. Total 9 batches were formulated. All 9 batches were evaluated for
entrapment efficiency (EE) and buoyancy. Among all batches DP4 shows
maximum entrapment efficiency (EE) and buoyancy and was considered as
optimized formulation. DP4 batch was further used for process optimization. The
process optimization was carried out at three different stirring speeds i.e. 1300,
1500 and 1700 rpm for three different stirring time period i.e. 1hr, 2hr and 3 hr and
another 9 batches were formulated. Out of all the batches DP13 showed the
spherical shape of microballoons without formation of flakes. Optimized batch
DP13 was evaluated for Zeta Potential, Particle Size Distribution which show -
41.8mV and 1.344 μm particle size, SEM, XRD Analysis. Batch DP13 was
charged for stability and were placed in glass vials container and stored at ICH
storage condition (2°C - 4°C Refrigeration condition , 30 ± 2°C / 60% ± 5% RH ,
40 ± 2°C / 75% ± 5% RH ) for a period of 30 days. The samples were analyzed for
physical appearance, buoyancy and for the drug release after 30 days. After 1
months samples were withdrawn and microballoons showed no change in physical
appearances, buoyancy and drug release, which indicate that the microballoons
were stable.
Keywords: Telmisartan, Microballoons, Emulsion solvent diffusion technique,
Buoyancy, Entrapment Efficiency.
DESIGN AND ASSESSMENT OF COLON SPECIFIC DRUG DELIVERY OF CELECOXIB USING PU...Lakshmi
The document summarizes the design and assessment of a colon-specific drug delivery system for celecoxib using pulsincap technique. Celecoxib microcrystals were prepared using a rapid solvent change method and evaluated. The microcrystals were then used to prepare pulsincaps containing hydrogel plugs to provide a lag time before drug release. In vitro drug release studies were conducted on the pulsincaps to assess their ability to deliver celecoxib in a pulsatile manner to the colon. The aim was to improve solubility, target delivery to the colon, and minimize dosing frequency for the treatment of rheumatoid arthritis.
Biopharmaceutical system , methods of permeability , generic biologics, gener...Siddhapura Pratik
Biopharmaceutical classification system, methods of permeability, generic biologics ( biosimilar drug product), clinical significance of bioequivalence studies , special concerns in bioavailability and bioequivalence studies , Generic substitution
This document provides information on a presentation about pharmaceutical approaches to colon targeted drug delivery systems for treating diseases like Crohn's disease. It discusses the anatomy and physiology of the colon, diseases associated with the colon, drug absorption in the colon, and various approaches for colon targeted drug delivery including pH sensitive polymers, time controlled release systems, microbiologically triggered systems, and new approaches like pressure controlled, pulsatile, and multi particulate systems. The presentation aims to highlight the advantages and limitations of different colon targeted drug delivery approaches.
The document discusses colon targeted drug delivery systems. It begins by defining colon targeted drug delivery as targeting drugs to the lower parts of the GI tract, mainly the large intestine. This is done for various objectives like reducing dosing frequency or delivering drugs that would otherwise be degraded. Approaches to colon targeting include pH sensitive coatings, microbially triggered systems, and timed release. Evaluation methods include in vitro dissolution tests and studies using animal models. Key advantages are site specific delivery and protecting drugs from degradation, while challenges include multiple manufacturing steps and drug binding in the colon.
colon drug delivery- advantage and disadvantage of colon delivery, anatomy of colon in healthy and diseased state , different approaches (conventional and new) for colon delivery, in vitro and in vivo evaluation
Colon-specific drug delivery (CDDS) aims to target drug release and absorption in the colon for local treatment of colonic diseases or systemic delivery of proteins and peptides. The document discusses the anatomy and physiology of the colon, factors governing colonic drug delivery, and various pharmaceutical approaches for CDDS including pH-sensitive systems, microbially triggered systems, and timed or controlled release platforms. Evaluation methods for CDDS include in vitro drug release tests under simulated gastric and intestinal conditions and in vitro enzymatic degradation assays.
Theoretical background on GastroPlus Simulation SoftwareArpitha Aarushi
this slides tells about Theoretical background on GastroPlus Simulation Software, basic ACAT model, and schematic diagram of compartment and sub compartment model.
This document discusses various pharmaceutical approaches for colon specific drug delivery systems. It begins with an introduction to colon specific drug delivery and the physiological considerations. It then describes various approaches in detail, including covalent linkage of drugs to carriers like azo conjugates, cyclodextrin conjugates, and polymeric prodrugs. It also discusses approaches to deliver intact molecules to the colon using coatings with pH sensitive or biodegradable polymers, embedding in matrices, timed release systems, and more. The document provides examples and details for each approach. It concludes with a brief section on evaluating colon specific drug delivery systems.
This presentation includes introduction, physiology of GIT, factors affecting GRDDS, Advantages and disadvantages, approaches to GRDDS and their mechanism, some of the marketed products using GRDDS mechanism.
Formulation Approaches For Gastro Retentive Drug DeliveryNaman Pant
1) Gastroretentive drug delivery systems are formulations designed to remain in the stomach for an extended period of time in order to allow drugs to be released over a prolonged period.
2) There are several approaches to gastric retention including floating systems, expandable systems, and bioadhesive systems. Floating systems have a lower density than gastric fluids while expandable systems swell upon contact with gastric fluid.
3) Gastroretentive systems provide benefits like improved drug absorption, reduced dosing, and site-specific drug delivery to the stomach. However, challenges include dose dumping and poor correlation between in vitro tests and in vivo performance.
Design of gastroretentive bilayer floating films of propranolol hydrochloride...Namdeo Shinde
This document summarizes a research study on the design of bilayer floating films for delivery of propranolol hydrochloride and rosuvastatin calcium. The study aimed to develop a single dosage form to provide therapeutic effects for hypertension and hyperlipidemia simultaneously. Various polymers and plasticizers were evaluated for their effects on film properties and drug release. Bilayer films were prepared using solvent casting method, with an immediate release layer of rosuvastatin and a sustained release layer of propranolol. The films were characterized for drug content, floating behavior, drug release and stability studies. The bilayer floating film system showed potential for gastroretention and controlled delivery of both drugs for cardiovascular diseases.
In recent years many advancement has been made in research and development of Oral Drug Delivery System. Concept of Novel Drug Delivery System arose to overcome the certain aspect related to physicochemical properties of drug molecule and the related formulations.
Purpose of this review is to compile the recent literature with special focus on Gastro Retentive Drug Delivery Systems to give an update
on pharmaceutical approaches used in enhancing the Gastric Residence Time (GRT). Various approaches are currently used including Gastro Retentive Floating Drug Delivery Systems(GRFDDS),swelling and expanding system, polymeric bioadhesive systems, modifiedshape
systems, high density system and other delayed gastric emptying devices. These systems are very helpful to different problem solve during the formulation of different dosage form. The present work also focuses on the polymers used in floating drug delivery systems
mostly from natural origin. Floating drug delivery systems are less dense than gastric fluids; hence remain buoyant in the upper GIT for a
prolonged period, releasing the drug at the desired/ predeterminedrate. This review article focuses on the recent technological development in floating drug delivery systems with special emphasis on the principal mechanism of floatation and advantages of achieving gastric
retention, brief collection on various polymers employed for floating drug delivery systems etc. In addition this review also summarizes the In –Vitro and In -Vivo studies to evaluate their performance and also their future potential.
This document summarizes a seminar presentation on colon-specific drug delivery. It discusses targeting delivery of drugs to the colon to treat diseases like ulcerative colitis and Crohn's disease. Various pharmaceutical approaches for colon-specific delivery are described, including pH sensitive systems, microbial triggered systems, and time release systems. Platform technologies for colon delivery like PULSINCAP and OROS-CT are also outlined. The document concludes that colonic drug delivery presents many challenges but also opportunities to improve therapy for colonic diseases.
The document discusses colon drug delivery systems. It describes the colon as a site for local and systemic drug delivery to treat diseases like Crohn's disease and ulcerative colitis. Various methods are described for targeting drug delivery to the colon, including the use of prodrugs, pH-sensitive polymers, biodegradable polymers, and timed release systems. Advantages of colon targeting include treatment of local colon diseases, bypassing first-pass metabolism, and reduced side effects. Limitations include multiple manufacturing steps and potential drug binding in the colon. The document then discusses various approaches for colon drug delivery, including the use of pH-sensitive polymers, time-dependent systems, microbially-triggered delivery, bioadhesive systems,
This document provides an overview of 7 chapters focused on in situ and in vitro models for assessing drug absorption. The chapters cover models of the skin, small intestine, colon, buccal mucosa, nasal cavity, lung, and various epithelial and endothelial barriers. A variety of in situ and in vitro techniques are discussed, including perfused organ models, cell culture systems, and excised tissue preparations. The models vary in their complexity and ability to predict in vivo absorption, with in situ techniques generally providing a more physiologically relevant system compared to simpler in vitro methods.
This document discusses colon targeted drug delivery systems. It begins by stating that colon targeted delivery is used to deliver substances that are degraded in the stomach, such as proteins and peptides. It then discusses various approaches to colon targeted delivery including pH sensitive polymers, delayed release systems, and microbial triggered delivery. The document covers the advantages of colon targeted systems, limitations, factors affecting delivery like gastric emptying and colonic pH, and provides examples of technologies like pulsincap and osmotic systems. It concludes with a discussion of evaluation methods and references.
This document presents a study on the design and in-vitro evaluation of floating tablets of Gabapentin. Gabapentin was chosen as a model drug candidate for a gastroretentive floating drug delivery system due to its narrow absorption window and solubility issues. A 32 full factorial design was used to study the effect of HPMC K100M polymer concentration and citric acid on tablet properties. Tablets were prepared by direct compression and evaluated for drug release kinetics, which followed Higuchi matrix and zero order models. The optimized batch with 99.06% drug release at 12 hours was found to be GFT7. A stability study showed no changes in this batch over one month. The study demonstrated that floating gabap
This document summarizes floating drug delivery systems (FDDS), which are designed to remain in the stomach for a prolonged period of time. The document begins by describing gastric physiology and emptying processes. It then classifies and describes different types of FDDS, including single and multiple unit systems that are effervescent (gas-generating) or non-effervescent. Effervescent systems use carbon dioxide to float, while non-effervescent systems swell upon contact with gastric fluid. The document also discusses evaluation methods and applications of FDDS to improve drug bioavailability.
Gestro retention drug delivery system, by dr. umesh kumar sharma & arathy...Dr. UMESH KUMAR SHARMA
The document discusses gastro-retentive drug delivery systems (GRDDS). GRDDS are designed to remain in the stomach for an extended period of time to allow for prolonged and continuous drug release. This can improve drug bioavailability and targeting of drugs to the upper gastrointestinal tract. Various approaches are used to prolong gastric retention time including floating drug delivery systems, high density systems, swellable systems, and mucoadhesive systems. Key factors affecting gastric retention time include density, size, shape, and meal content of the dosage form.
This document presents an overview of gastroretentive drug delivery systems (GRDDS). It discusses how GRDDS can increase the gastric residence time and help deliver drugs that need to be released in the stomach or upper intestine. The document outlines different technologies for GRDDS, including floating drug delivery systems, swelling systems, bioadhesive systems, and high density approaches. It also notes some drugs that are suitable candidates for GRDDS and reviews advantages like improved bioavailability as well as limitations like unsuitability for drugs that are unstable in the stomach.
This document provides definitions and concepts for various controlled and novel drug delivery systems including parenteral, transdermal, buccal, rectal, nasal, and implantable systems. It defines controlled release dosage forms as those that release drug at a constant rate to provide invariant plasma concentrations. Novel drug delivery systems are described as formulations that safely transport pharmaceutical compounds as needed. Key aspects and examples of each delivery system are summarized.
Colon Specific Drug Delivery System: Basics and ApproachesNone
Colon drug delivery and approaches can target drugs specifically to the colon through various pH sensitive, time controlled, or microbially triggered mechanisms. Drugs suitable for colon targeting include those for inflammatory bowel disease, colon cancer, protein/peptide delivery, and infectious diseases. Approaches include pH sensitive polymer coatings, time controlled systems, microbially triggered delivery using enzymes, and novel approaches like pressure controlled, osmotic controlled, pulsincap, and port systems. Evaluation involves in vitro dissolution and degradation testing as well as in vivo parameters like drug delivery index and animal studies.
The document discusses colon targeted drug delivery. It begins with an introduction describing the desirability of targeted colon delivery. It then discusses the anatomy of the colon, criteria for drug selection, and various approaches for colon targeting including pH sensitive polymers, delayed release systems, microbially triggered delivery, and innovative devices. It also covers evaluation methods and concludes that developing an effective oral colon delivery system remains a challenge that requires consideration of the entire gastrointestinal tract environment.
The document discusses various approaches for targeting drug delivery to the colon, including conventional and new approaches. Conventional approaches include pH sensitive polymer coatings, delayed release systems, and use of prodrugs. Newer approaches discussed are osmotic controlled delivery systems, intestinal pressure controlled colon delivery capsules, nanoparticle systems, pulsincap systems, and azo hydrogels. The colon's anatomy, physiology, and factors affecting drug absorption are also summarized.
This document provides an overview of mouth dissolving tablets (MDT), including promising drug candidates, popular disintegrants used, formulation techniques, marketed products, and evaluation methods. MDTs are designed to dissolve rapidly in the mouth within 3 minutes before swallowing for improved patient compliance. Common techniques for MDT formulation include lyophilization, moulding, direct compression, and sublimation. Evaluation of MDTs involves testing of granules, tablets, and dissolution properties. Future research aims to identify suitable drug candidates and excipients while improving dissolution times and patient acceptability.
This document discusses various pharmaceutical approaches for colon specific drug delivery systems. It begins with an introduction to colon specific drug delivery and the physiological considerations. It then describes various approaches in detail, including covalent linkage of drugs to carriers like azo conjugates, cyclodextrin conjugates, and polymeric prodrugs. It also discusses approaches to deliver intact molecules to the colon using coatings with pH sensitive or biodegradable polymers, embedding in matrices, timed release systems, and more. The document provides examples and details for each approach. It concludes with a brief section on evaluating colon specific drug delivery systems.
This presentation includes introduction, physiology of GIT, factors affecting GRDDS, Advantages and disadvantages, approaches to GRDDS and their mechanism, some of the marketed products using GRDDS mechanism.
Formulation Approaches For Gastro Retentive Drug DeliveryNaman Pant
1) Gastroretentive drug delivery systems are formulations designed to remain in the stomach for an extended period of time in order to allow drugs to be released over a prolonged period.
2) There are several approaches to gastric retention including floating systems, expandable systems, and bioadhesive systems. Floating systems have a lower density than gastric fluids while expandable systems swell upon contact with gastric fluid.
3) Gastroretentive systems provide benefits like improved drug absorption, reduced dosing, and site-specific drug delivery to the stomach. However, challenges include dose dumping and poor correlation between in vitro tests and in vivo performance.
Design of gastroretentive bilayer floating films of propranolol hydrochloride...Namdeo Shinde
This document summarizes a research study on the design of bilayer floating films for delivery of propranolol hydrochloride and rosuvastatin calcium. The study aimed to develop a single dosage form to provide therapeutic effects for hypertension and hyperlipidemia simultaneously. Various polymers and plasticizers were evaluated for their effects on film properties and drug release. Bilayer films were prepared using solvent casting method, with an immediate release layer of rosuvastatin and a sustained release layer of propranolol. The films were characterized for drug content, floating behavior, drug release and stability studies. The bilayer floating film system showed potential for gastroretention and controlled delivery of both drugs for cardiovascular diseases.
In recent years many advancement has been made in research and development of Oral Drug Delivery System. Concept of Novel Drug Delivery System arose to overcome the certain aspect related to physicochemical properties of drug molecule and the related formulations.
Purpose of this review is to compile the recent literature with special focus on Gastro Retentive Drug Delivery Systems to give an update
on pharmaceutical approaches used in enhancing the Gastric Residence Time (GRT). Various approaches are currently used including Gastro Retentive Floating Drug Delivery Systems(GRFDDS),swelling and expanding system, polymeric bioadhesive systems, modifiedshape
systems, high density system and other delayed gastric emptying devices. These systems are very helpful to different problem solve during the formulation of different dosage form. The present work also focuses on the polymers used in floating drug delivery systems
mostly from natural origin. Floating drug delivery systems are less dense than gastric fluids; hence remain buoyant in the upper GIT for a
prolonged period, releasing the drug at the desired/ predeterminedrate. This review article focuses on the recent technological development in floating drug delivery systems with special emphasis on the principal mechanism of floatation and advantages of achieving gastric
retention, brief collection on various polymers employed for floating drug delivery systems etc. In addition this review also summarizes the In –Vitro and In -Vivo studies to evaluate their performance and also their future potential.
This document summarizes a seminar presentation on colon-specific drug delivery. It discusses targeting delivery of drugs to the colon to treat diseases like ulcerative colitis and Crohn's disease. Various pharmaceutical approaches for colon-specific delivery are described, including pH sensitive systems, microbial triggered systems, and time release systems. Platform technologies for colon delivery like PULSINCAP and OROS-CT are also outlined. The document concludes that colonic drug delivery presents many challenges but also opportunities to improve therapy for colonic diseases.
The document discusses colon drug delivery systems. It describes the colon as a site for local and systemic drug delivery to treat diseases like Crohn's disease and ulcerative colitis. Various methods are described for targeting drug delivery to the colon, including the use of prodrugs, pH-sensitive polymers, biodegradable polymers, and timed release systems. Advantages of colon targeting include treatment of local colon diseases, bypassing first-pass metabolism, and reduced side effects. Limitations include multiple manufacturing steps and potential drug binding in the colon. The document then discusses various approaches for colon drug delivery, including the use of pH-sensitive polymers, time-dependent systems, microbially-triggered delivery, bioadhesive systems,
This document provides an overview of 7 chapters focused on in situ and in vitro models for assessing drug absorption. The chapters cover models of the skin, small intestine, colon, buccal mucosa, nasal cavity, lung, and various epithelial and endothelial barriers. A variety of in situ and in vitro techniques are discussed, including perfused organ models, cell culture systems, and excised tissue preparations. The models vary in their complexity and ability to predict in vivo absorption, with in situ techniques generally providing a more physiologically relevant system compared to simpler in vitro methods.
This document discusses colon targeted drug delivery systems. It begins by stating that colon targeted delivery is used to deliver substances that are degraded in the stomach, such as proteins and peptides. It then discusses various approaches to colon targeted delivery including pH sensitive polymers, delayed release systems, and microbial triggered delivery. The document covers the advantages of colon targeted systems, limitations, factors affecting delivery like gastric emptying and colonic pH, and provides examples of technologies like pulsincap and osmotic systems. It concludes with a discussion of evaluation methods and references.
This document presents a study on the design and in-vitro evaluation of floating tablets of Gabapentin. Gabapentin was chosen as a model drug candidate for a gastroretentive floating drug delivery system due to its narrow absorption window and solubility issues. A 32 full factorial design was used to study the effect of HPMC K100M polymer concentration and citric acid on tablet properties. Tablets were prepared by direct compression and evaluated for drug release kinetics, which followed Higuchi matrix and zero order models. The optimized batch with 99.06% drug release at 12 hours was found to be GFT7. A stability study showed no changes in this batch over one month. The study demonstrated that floating gabap
This document summarizes floating drug delivery systems (FDDS), which are designed to remain in the stomach for a prolonged period of time. The document begins by describing gastric physiology and emptying processes. It then classifies and describes different types of FDDS, including single and multiple unit systems that are effervescent (gas-generating) or non-effervescent. Effervescent systems use carbon dioxide to float, while non-effervescent systems swell upon contact with gastric fluid. The document also discusses evaluation methods and applications of FDDS to improve drug bioavailability.
Gestro retention drug delivery system, by dr. umesh kumar sharma & arathy...Dr. UMESH KUMAR SHARMA
The document discusses gastro-retentive drug delivery systems (GRDDS). GRDDS are designed to remain in the stomach for an extended period of time to allow for prolonged and continuous drug release. This can improve drug bioavailability and targeting of drugs to the upper gastrointestinal tract. Various approaches are used to prolong gastric retention time including floating drug delivery systems, high density systems, swellable systems, and mucoadhesive systems. Key factors affecting gastric retention time include density, size, shape, and meal content of the dosage form.
This document presents an overview of gastroretentive drug delivery systems (GRDDS). It discusses how GRDDS can increase the gastric residence time and help deliver drugs that need to be released in the stomach or upper intestine. The document outlines different technologies for GRDDS, including floating drug delivery systems, swelling systems, bioadhesive systems, and high density approaches. It also notes some drugs that are suitable candidates for GRDDS and reviews advantages like improved bioavailability as well as limitations like unsuitability for drugs that are unstable in the stomach.
This document provides definitions and concepts for various controlled and novel drug delivery systems including parenteral, transdermal, buccal, rectal, nasal, and implantable systems. It defines controlled release dosage forms as those that release drug at a constant rate to provide invariant plasma concentrations. Novel drug delivery systems are described as formulations that safely transport pharmaceutical compounds as needed. Key aspects and examples of each delivery system are summarized.
Colon Specific Drug Delivery System: Basics and ApproachesNone
Colon drug delivery and approaches can target drugs specifically to the colon through various pH sensitive, time controlled, or microbially triggered mechanisms. Drugs suitable for colon targeting include those for inflammatory bowel disease, colon cancer, protein/peptide delivery, and infectious diseases. Approaches include pH sensitive polymer coatings, time controlled systems, microbially triggered delivery using enzymes, and novel approaches like pressure controlled, osmotic controlled, pulsincap, and port systems. Evaluation involves in vitro dissolution and degradation testing as well as in vivo parameters like drug delivery index and animal studies.
The document discusses colon targeted drug delivery. It begins with an introduction describing the desirability of targeted colon delivery. It then discusses the anatomy of the colon, criteria for drug selection, and various approaches for colon targeting including pH sensitive polymers, delayed release systems, microbially triggered delivery, and innovative devices. It also covers evaluation methods and concludes that developing an effective oral colon delivery system remains a challenge that requires consideration of the entire gastrointestinal tract environment.
The document discusses various approaches for targeting drug delivery to the colon, including conventional and new approaches. Conventional approaches include pH sensitive polymer coatings, delayed release systems, and use of prodrugs. Newer approaches discussed are osmotic controlled delivery systems, intestinal pressure controlled colon delivery capsules, nanoparticle systems, pulsincap systems, and azo hydrogels. The colon's anatomy, physiology, and factors affecting drug absorption are also summarized.
This document provides an overview of mouth dissolving tablets (MDT), including promising drug candidates, popular disintegrants used, formulation techniques, marketed products, and evaluation methods. MDTs are designed to dissolve rapidly in the mouth within 3 minutes before swallowing for improved patient compliance. Common techniques for MDT formulation include lyophilization, moulding, direct compression, and sublimation. Evaluation of MDTs involves testing of granules, tablets, and dissolution properties. Future research aims to identify suitable drug candidates and excipients while improving dissolution times and patient acceptability.
Nanoparticles based drug delivery systems for treatment ofaisha rauf
The document discusses nanoparticles for targeting intracellular bacterial infections. It notes that some bacteria can survive and replicate inside cells, avoiding immune responses, making them difficult to treat. Nanoparticles can selectively target and destroy pathogenic bacteria by encapsulating antimicrobial drugs and releasing them at the site of infection. Various types of nanoparticles are investigated for drug delivery, including polymeric nanoparticles, hydrogels, lipid nanoparticles, and metal nanoparticles like gold. Nanoparticles show promise for overcoming antibiotic resistance and improving treatment of intracellular bacterial infections.
1. Orally disintegrating tablets (ODTs) are solid dosage forms that disintegrate rapidly, usually within seconds, when placed on the tongue without the need for water.
2. ODTs are appropriate for patients who have difficulty swallowing tablets or capsules, such as elderly patients, children, and bedridden patients. They can improve medication compliance and therapeutic effects.
3. Key factors in developing ODTs include selecting drugs that have appropriate properties, using superdisintegrants and other excipients to enable rapid disintegration, and employing manufacturing techniques like direct compression that avoid moisture.
This document provides an overview of oral disintegrating tablets (ODTs), including their development, technologies used in their production, and evaluation methods. ODTs are solid dosage forms that disintegrate rapidly in the mouth, typically within 3 minutes, without water. They offer advantages over conventional tablets for patients who have difficulty swallowing. The document reviews various ODT production technologies such as freeze drying, spray drying, mass extrusion, and direct compression. It also discusses ideal properties, advantages, and limitations of ODTs.
Liposomes are concentric bilayered vesicles in which an aqueous core is entirely enclosed by a membranous lipid bilayer mainly composed of natural or synthetic phospholipids.
Liposomes are spherical microscopic vesicles consisting phospholipids bilayers which enclose aqueous compartments.
The size of a liposome ranges from some 20 nm up to several micrometers.
Liposomes were first produced in England in 1961 by Alec D. Bangham, who was studying phospholipids and blood clotting.
Small unilamellar vesicles (SUV), 25 to 100 nm in size that consist of a single bilayer
Large unilamellar vesicle (LUV), 100 to 500 nm in size that consist of a single bilayer
Multilamellar vesicle (MLV), 200 nm to several microns, that consist of two or more concentric bilayer
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate aqueous content. They are used to deliver vaccines, drugs, and other substances to target cells and organs. Liposomes are composed of natural or synthetic phospholipids, along with cholesterol and other lipids. Various preparation methods are used to load drugs into liposomes either before or after formation. Liposomes offer advantages like reduced toxicity and targeted delivery compared to free drugs. However, liposomes also have challenges like low drug loading capacity and lack of long-term stability.
The document discusses liposomes, including their principle, definition, discovery, composition, mechanisms of formation, classification, preparation methods, drug encapsulation, characterization, stability, uses, and commercial products. Liposomes are spherical vesicles composed of phospholipid bilayers that can encapsulate drugs for targeted delivery. They were discovered in 1965 and offer advantages like biocompatibility and protection of drugs, though production costs are high and leakage can occur.
This document summarizes the formulation and evaluation of fast dissolving tablet dosages of felodipine. It discusses the drug profile, aim/objectives of developing fast dissolving tablets, materials/equipment used, preparation of formulations using different superdisintegrants (crospovidone, crosscarmellose sodium, sodium starch glycolate), and evaluation of tablet properties (thickness, hardness, friability) and performance (disintegration time, dissolution). 9 formulations were developed and evaluated, with F3 showing the fastest disintegration time of 116 seconds and highest drug release of 90.58% within 30 minutes. The study demonstrated the potential of using superdisintegrants to develop fast dissolving felodipine tablets for improved patient compliance and
Formulation development and evalution of matrix tablet ofGajanan Ingole
The document describes the development of a matrix tablet for oral delivery of an antihypertensive drug (NSL) using pH dependent and independent polymers. It includes sections on introduction, literature review, drug and excipient profiles, aim and objectives, rationale, materials and equipment, experimental work, results, discussion, and references. The key steps involved preformulation studies, formulation of matrix tablets, optimization studies to match the in vitro dissolution profile of a marketed reference product, and stability studies. The optimized formulation was found to release the drug in a controlled manner for 24 hours.
NANOTECHNOLOGY comprises technological developments on the nanometer scale, usually 0.1 to 100 nm. Nanotechnology, the science of the small. Nano is Greek for dwarf, and nanoscience deals with the study of molecular and atomic particles.
Formulation and evaluation of fast dissolving tablet- by aryan and rajeshSridhar Sri
This document provides an overview of a study to formulate and evaluate fast dissolving tablets of domperidone. It begins with an introduction that defines fast dissolving tablets and lists their requirements and advantages. It then outlines the objectives, plan of work, drug and excipient profiles, materials, and methodology for the study. The methodology section describes preformulation tests conducted on domperidone as well as evaluation tests that will be performed on the formulated tablets, including disintegration time, drug content, and in vitro drug release. The document provides background information needed to understand and carry out the research project on developing a fast dissolving tablet of domperidone.
This document discusses regulatory considerations for over-the-counter (OTC) drugs in India and the United States. It provides definitions of OTC drugs and differences between prescription and OTC drugs in both countries. The key criteria for classifying drugs as OTC in the US and India are described. The document also examines regulations around marketing authorization, labeling, and advertising of OTC drugs. It evaluates the branded bisacodyl product Dulcolax and generic bisacodyl product Bisomer 5 based on tests specified in the Indian Pharmacopoeia. The evaluation found both products met requirements. The document concludes with recommendations for improving OTC drug regulations and classification in India.
Liposomes are spherical vesicles made of concentric phospholipid bilayers. They were first produced in 1961 and can range in size from 20 nm to several micrometers. Liposomes provide advantages like selective targeting to tumors, increased drug efficacy, and reduced toxicity, but also have disadvantages such as high production costs and drug leakage. Common methods for preparing liposomes include film hydration, ethanol injection, and detergent removal.
This document provides an overview of liposomes. It begins with an introduction describing liposomes as concentric bilayer vesicles composed mainly of phospholipids and cholesterol. It then covers the mechanism of liposome formation, classifications, biological fate, preparation methods, characterization techniques, advantages and disadvantages, and applications. Preparation methods discussed include physical dispersion, solvent dispersion, detergent solubilization, and various size reduction/increase techniques. Characterization includes assessing size, shape, lamellarity, surface charge, drug release, and encapsulation efficiency using tools like microscopy, NMR, and chromatography.
GASTRO RETENTIVE DRUG DELIVERY SYSTEM PPT PDF.pdfVIJAY JADHAV
This document outlines a student project to develop a gastroretentive floating tablet of the antihypertensive drug propranolol hydrochloride using polymers like HPMC and HPC to increase its residence time in the stomach and bioavailability. The objectives are to study the drug's bioavailability, residence time in stomach, dosing frequency, and absorption window. Materials include propranolol HCl and polymers. Tablets will be formulated by direct compression and evaluated for properties, in vitro drug release kinetics, and in vivo gastrointestinal residence time. The literature review covers gastroretentive drug delivery systems and previous work formulating propranolol HCl tablets.
ABSTRACT- The objective of our present study was to develop multiparticulate gastro retentive drug delivery system
of Curcumin. The gastro retentive drug delivery system can be formulated to improve the absorption and bio-availability
of curcumin by retaining the system into the stomach for prolonged period of time. The floating drug delivery system of
curcumin was prepared by emulsion solvent diffusion method by using ethyl cellulose, Eudragit L100, HPMC, Phyllium
husk polymers in varying concentration. Formulations were evaluated for percent yield, particle size, entrapment
efficiency, in vitro buoyancy as well as in vitro release studies. The optimized formulations show good buoyancy and in
vitro controlled release of Curcumin.
Key-words- Floating microsphere, Ethyl cellulose, Hydroxypropyl Methyl cellulose (HPMC), Eudragit L 100, Phyllium
Husk
This document describes the development and evaluation of carvedilol phosphate gastroretentive floating tablets using a 32 factorial design. Carvedilol phosphate is a drug that belongs to BCS Class II and is indicated for hypertension and heart failure. Floating tablets were prepared using varying concentrations of guar gum and sodium bicarbonate as polymers to control the release of the water soluble drug. Nine formulations were designed and evaluated for properties like drug content, floating lag time, and in vitro drug release using kinetic models. The results showed that all formulations met pharmacopeial standards and formulation F8 containing 25% guar gum and 3.75% sodium bicarbonate best matched the marketed product with respect to drug release.
The document discusses the formulation and evaluation of an artemether sustained release floating bilayer tablet. It aims to develop a floating drug delivery system for artemether to increase its gastric residence time and provide sustained release to ensure optimal drug levels in the blood and minimize side effects. The document provides background on floating drug delivery systems and reviews previous literature on developing such systems for other drugs. It then gives information on the drug artemether and outlines the objectives and methodology that will be used in the study.
This document describes the design and evaluation of atenolol gastroretentive floating tablets using a 3^2 factorial design. Nine formulations were prepared using different concentrations of HPMC K15M and sodium bicarbonate as independent variables. The dependent variables measured were the time taken for 10%, 50%, 75%, and 90% drug dissolution. Formulation F8, containing 25% HPMC K15M and 3.75% sodium bicarbonate, showed prolonged drug release similar to the marketed product and followed Higuchi kinetics with non-Fickian diffusion-controlled drug release. Polynomial equations were developed relating the independent and dependent variables.
Abstract
The main objective of present research work is to formulate the floating tablets of atenolol using 32 factorial design. Atenolol, β-blocker belongs to Biopharmaceutical Classification System Class-III. The floating tablets of atenolol were prepared employing different concentrations of hydroxypropyl methylcellulose (HPMC) K15M and sodium bicarbonate in different combinations by direct compression technique using 32 factorial design. The concentration of HPMC K15M and sodium bicarbonate required to achieve desired drug release was selected as independent variables, X1 and X2, respectively, whereas time required for 10% of drug dissolution (t10%), 50% (t50%), 75% (t75%), and 90% (t90%) were selected as dependent variables. Totally, nine formulations were designed and are evaluated for hardness, friability, thickness, % drug content, floating lag time, in vitro drug release. From the results, concluded that all the formulation were found to be within the pharmacopoeial limits and the in vitro dissolution profiles of all formulations were fitted into different Kinetic models, the statistical parameters like intercept (a), slope (b) and regression coefficient (r) were calculated. Polynomial equations were developed for t10%, t50%, t75%, t90%. Validity of developed polynomial equations was verified by designing 2 checkpoint formulations (C1, C2). According to SUPAC guidelines the formulation (F8) containing combination of 25% HPMC K15M and 3.75% sodium bicarbonate, is the most similar formulation (similarity factor f2 = 87.797, dissimilarity factor f1 = 2.248 and no significant difference, t = 0.098) to marketed product (BETACARD). The selected formulation (F8) follows Higuchi’s kinetics, and the mechanism of drug release was found to be non-Fickian diffusion (n = 1.029, Super Case-II transport).
Gastric emptying is a complex process, one that is highly variable and makes in vivo performance of drug delivery systems uncertain. A controlled drug delivery system with prolonged residence time in the stomach can be great practical importance for drugs with an absorption window in the upper small intestine. The main limitations are attributed to the inter- and intra-subject variability of gastrointestinal (GI) transit time and to the non-uniformity of drug absorption throughout the alimentary canal. Floating drug delivery systems are useful in such applications. Floating microspheres have been gaining attention due to the uniform distribution of these multiple-unit dosage forms in the stomach, which results in more reproducible drug absorption and reduced risk of local irritation. The present research briefly addresses the physiology of the gastric emptying process with respect to floating drug delivery systems. Floating microsphere were prepared by solvent evapouration method, using hydroxylpropyl methylcellulose (HPMC), ethyl cellulose (EC), Eudragit S 100 polymer in varying ratios. The shape and surface morphology of the microspheres were characterised by differential scanning calorimetry and scanning electron microscopy.
Formulation and Evaluation of Floating in Situ Gel of LafutidineAI Publications
Gastroesophageal reflux disease (GERD) and peptic ulcers are prevalent gastrointestinal disorders that significantly impact the quality of life of affected individuals. Lafutidine, a histamine H2-receptor antagonist, has demonstrated effectiveness in managing these conditions. However, its short gastric residence time limits its therapeutic efficacy. To address this limitation, we aimed to formulate and evaluate a floating in situ gel of Lafutidine for prolonged gastric retention and enhanced therapeutic outcomes. In vivo studies were conducted on albino Wistar rats to assess the pharmacokinetic parameters and gastric residence time. The pharmacokinetic evaluation demonstrated that the floating in situ gel exhibited improved Lafutidine bioavailability compared to the conventional dosage form. Gastric residence time was significantly extended, enhancing Lafutidine's therapeutic efficacy. Overall, the formulation and evaluation of the floating in situ gel of Lafutidine demonstrated its potential as an effective drug delivery system for the management of GERD and peptic ulcers. The extended gastric retention and enhanced bioavailability of Lafutidine make this formulation a promising option for improving patient compliance and therapeutic outcomes in the treatment of these gastrointestinal disorders. Further clinical studies are warranted to establish its clinical efficacy and safety profile.
Formulation and Evaluation of Floating Matrix Tablets of an Antipsychotic DrugBRNSSPublicationHubI
This document describes the formulation and evaluation of floating matrix tablets containing ziprasidone, an antipsychotic drug, for gastroretentive drug delivery. Ziprasidone was selected as a model drug and formulated into multi-unit floating tablets using various fatty and hydrophilic polymers like Gelucire 43/01, HPMC K4M, and HPMC K100M via wet and melt granulation techniques. The formulated tablets were evaluated for drug content, physical properties, in vitro buoyancy, and floating lag time. The results showed that tablets containing Gelucire 43/01 as the polymer had optimal floating properties and drug release characteristics, making it a suitable candidate for the controlled delivery of ziprasidone in
Formulation and Evaluation of Gabapentin Mucoadhesive Gastro Retentive Tablets.pharmaindexing
This document describes the formulation and evaluation of gabapentin mucoadhesive gastroretentive tablets. Various tablet formulations were prepared using different concentrations of mucoadhesive polymers like carbopol 934P, sodium CMC, and sodium alginate. The tablets were evaluated for parameters like thickness, weight variation, hardness, drug content, swelling index, and mucoadhesive strength. In vitro drug release studies showed that a formulation containing 0.5% carbopol 934P (F-IV) exhibited slowest drug release over 12 hours compared to other formulations. Stability studies of F-IV showed no significant changes in properties after 3 months of storage. The study concluded that mucoadhesive polymers can help
This document provides an overview of gastroretentive drug delivery systems (GRDDS). It begins with an introduction to GRDDS and their advantages such as improving bioavailability and overcoming physiological challenges. It then discusses modulation of gastric transit and the mechanisms of drug permeation. The document outlines the main types of GRDDS including high density, floating, and swelling/expanding systems. It also covers evaluations of GRDDS both in vitro and in vivo. The document concludes that GRDDS offer advantages for drugs that are poorly absorbed in the upper GI tract by maximizing absorption and bioavailability.
This document provides an overview of floating drug delivery systems (FDDS). FDDS are low-density drug delivery systems that remain buoyant in the stomach without affecting gastric emptying rate, resulting in increased gastric retention time and better control of drug concentrations. FDDS are useful for drugs that need to be absorbed in the stomach or have a narrow absorption window in the upper gastrointestinal tract. The document discusses the advantages and disadvantages of FDDS, examples of commercially available FDDS formulations, and different types of FDDS including effervescent systems that use gas-generating agents and non-effervescent systems. It concludes that FDDS can enhance bioavailability for certain drugs but may not be suitable for all drugs depending on factors like
In the present study, a gastro retentive micro particulate system was formulated with different Polymers by using
solvent evaporation technique. A series of 8 formulations was prepared based on 23 Design of experiments. The
formulated microspheres were evaluated flow characteristics, Practical yield (up to 80 %) and Encapsulation
efficiency (up to 94%). Scanning electron Microscopy confirmed their porous and spherical structure and the
particles were of the Size range of (65-525 μm). The release of drug at 1 hour and 8 hours’ time points were
taken as the measurable parameters for running the DOE experiments. According to design space Hollow
Microspheres formulated with Drug in the range of 50 to 70 mg/unit, Ethyl cellulose 7 cps in the range of 145 to
150 mg/unit and HPMC 5 cps in the range of 0.4 to 2 mg/unit were observed to have the best floating
characteristics and in vitro dissolution profile as per the preset target product profile. Stability studies showed no
significant change in the drug content in the formulations at 3 months accelerated condition. In this study
concluded that a micro particulate floating dosage form of an anti-infective drug can be successfully designed to
give controlled release and improved oral bioavailability.
KEYWORDS
Gastro retentive system, Ciprofloxacin Hcl, Ethyl Cellulose 7 cps, HPMC 5cps, Hollow microspheres.
Approaches Of Gastro-Retentive Drug Delivery System or GRDDSAkshayPatane
Approaches Of Gastro-Retentive Drug Delivery System
Includes:
Floating and Non-Floating drug delivery system with their subtypes
Like Non-effervescent system, Effervescent system, Raft forming system,
High Density system, Expandable system, Muco-adhesive system,
Super porous hydrogel system and Magnetic Systems, etc.
This document discusses the development of floating microspheres of Alfuzosin HCl to improve its bioavailability and achieve steady plasma concentrations. It aims to formulate a gastroretentive drug delivery system using polymers to develop floating microspheres. The document provides background on floating drug delivery systems, factors affecting gastric retention time, and approaches to gastroretentive drug delivery including floating, bioadhesive, expanding and high density systems. It outlines the rationale for developing a floating microsphere formulation of Alfuzosin HCl and lists the objectives of optimizing the formulation to improve drug release.
ABSTRACT
The main objective of present research work is to formulate the floating tablets of Carvedilol Phosphate using 32 factorial design. Carvedilol Phosphate, non-selective α1-β1-blocking agent belongs to BCS Class-II and Indicated for treatment of Hypertension/moderate Heart Failure. The Floating tablets of Carvedilol Phosphate were prepared employing different concentrations of HPMCK100M and Sodium bicarbonate in different combinations by Direct Compression technique using 32 factorial design. The concentration of HPMCK100M and Sodium bicarbonate required to achieve desired drug release was selected as independent variables, X1 and X2 respectively whereas, time required for 10% of drug dissolution (t10%), 50% (t50%), 75% (t75%) and 90% (t90%) were selected as dependent variables. Totally nine formulations were designed and are evaluated for hardness, friability, thickness, % drug content, Floating Lag time, In-vitro drug release. From the Results concluded that all the formulation were found to be with in the Pharmacopoeial limits and the In-vitro dissolution profiles of all formulations were fitted in to different Kinetic models, the statistical parameters like intercept (a), slope (b) & regression coefficient (r) were calculated. Polynomial equations were developed for t10%, t50%, t75%, t90%. Validity of developed polynomial equations were verified by designing 2 check point formulations (C1, C2). According to SUPAC guidelines the formulation (F8) containing combination of 25% HPMCK100M and 3.75% Sodium bicarbonate, is the most similar formulation (similarity factor f2=88.801, dissimilarity factor f1= 2.250 & No significant difference, t= 0.095) to marketed product (CARDIVAS). The selected formulation (F8) follows Higuchi’s kinetics, and the mechanism
The study evaluated the long-term effects of administering silibinin, epigallocatechin, quercetin, or rutin on the absorption and tissue distribution of zinc, copper, and iron in rats. The results showed that all flavonoids increased serum and tissue levels of the trace elements compared to controls. Specifically, the flavonoids increased absorption of all three elements and their availability in brain, kidney, and liver tissues. However, the effects varied between flavonoids, with epigallocatechin generally having the greatest effect on iron absorption and tissue levels. The study suggests long-term intake of high-dose flavonoid supplements could increase absorption and tissue accumulation of some trace elements.
This document provides an overview of floating drug delivery systems (FDDS). FDDS are low-density drug delivery systems that remain buoyant in the stomach without affecting gastric emptying rate, resulting in increased gastric retention time and better control of drug concentrations. There are two main types of FDDS - effervescent systems that use gas-generating agents to reduce density, and non-effervescent systems that rely on gel-forming or swellable polymers. FDDS can improve drug absorption for drugs that need to be absorbed in the stomach or have a narrow absorption window in the small intestine. Several commercially available FDDS products and patents are described. Factors like dosage form size and shape, gender, posture, and age
Floating drug delivery approach uses low-density systems that have sufficient buoyancy to flow over the
gastric contents and remains buoyant in the stomach without affecting the stomachic emptying rate for a
chronic period of time. This result is increased gastric retention time and better control of the fluctuations
in plasma drug concentration with a low risk of toxicity. Drugs, which are locally active in the stomach,
drugs having narrow absorption window and unstable in the intestine, and colonic environment, are the
potential drug candidates. The approach not only improves drug absorption but also minimizes the mucosal
irritation of drugs. As the approach requires a high fluid level in the stomach to float and work efficiently,
it makes the approach limited up to some extent. Many buoyant systems have been developed based on
granules, powders, capsules, tablets, laminated films, and hollow microspheres and few formulations have
been commercialized in the market at the present time. This review gives an overview of the approach of
floating drug delivery at present with sequential demystification thus enabling a greater understanding of
their role in medicine and drug delivery
1.
Kharia et al: Formulation and Evaluation of Polymeric Nanoparticles of an Antiviral Drug for Gastroretention
1557
International Journal of Pharmaceutical Sciences and Nanotechnology
Volume 4 • Issue 4 • January – March 2012
Research Paper
MS ID: IJPSN-8-19-11-KHARIA
Formulation and Evaluation of Polymeric Nanoparticles of
an Antiviral Drug for Gastroretention
1,2
3
1
A.A. Kharia , A.K. Singhai and R. Verma
1
Oriental College of Pharmacy, Bhopal, Madhya Pradesh, India
2
Uttarakhand Technical University, Dehradun, Uttarakhand, India
3
Lakshmi Narayan College of Pharmacy, Bhopal, Madhya Pradesh, India
Received August 19, 2011; accepted January 12, 2012
ABSTRACT
The aim of present study was to formulate and evaluate
nanoparticles of acyclovir by using different hydrophilic
polymers. Acyclovir was selected as a suitable drug for gastroretentive nanoparticles due to its short half life, low
bioavailability, high frequency of administration, and narrow
absorption window in stomach and upper part of GIT. The
nano-precipitation method was used to prepare nanoparticles
so as to avoid both chlorinated solvents and surfactants to
prevent their toxic effect on the body. Nanoparticles of
acyclovir were prepared by using hydrophilic polymers such as
bovine serum albumin, chitosan, and gelatin. The prepared
formulations were then characterized for particle size,
polydispersity index, zeta potential, loading efficiency,
encapsulation efficiency and drug-excipient compatibility. The
prepared nanoparticulate formulations of acyclovir with
different polymers in 1:1 ratio have shown particle size in the
range of 250.12-743.07 nm, polydispersity index (PDI) in the
range of 0.681-1.0, zeta potential in the range of -14.2 to +33.2
mV, loading efficiency in the range of 8.74-17.54%, and
entrapment efficiency in the range of 55.7%-74.2%.
Nanoparticulate formulation prepared with chitosan in 1:1 ratio
showed satisfactory results i.e. average particle size 312.04
nm, polydispersity index 0.681, zeta potential 33.2 mV, loading
efficiency 17.54%, and entrapment efficiency 73.4%. FTIR
study concluded that no major interaction occurred between
the drug and polymers used in the present study.
KEYWORDS: Nanoparticles; gastro-retentive; nano-precipitation, polydispersity index, zeta potential; entrapment efficiency.
Introduction
The oral route of drug administration is the most
convenient and commonly used method of drug delivery
due to their considerable therapeutic advantages such as
ease of administration, patient compliance, and
flexibility in formulation (Garg et al., 2008; Gupta et al.,
2007). However, this route has several physiological
problems, such as inability to restrain and locate the
controlled drug delivery system within the desired region
of the gastrointestinal tract due to variable gastric
emptying and motility. Furthermore, the relatively brief
gastric emptying time in humans, which normally means
2-3 hours through the major absorption zone, i.e.,
stomach and upper part of the intestine, can result in
incomplete drug release from the drug delivery system
leading to reduced efficacy of the administered dose
(Rouge et al., 1996). These difficulties have prompted
researchers to design a drug delivery system which can
stay in the stomach for prolonged and predictable period
(Deshpande et al., 1996; Hwang et al., 1998). Several
attempts are being made to develop a controlled drug
delivery system, which can provide therapeutically
effective plasma drug concentration for a longer period,
thereby reducing the dosing frequency and minimizing
fluctuations in plasma drug concentration at steady-state
by delivering the drug in a controlled and reproducible
manner (Sood et al., 2003).
Different methodologies have been reported in the
literature to increase the gastric retention of drugs, like
intra-gastric floating systems, hydro dynamically
balanced
systems,
extendable
or
expandable,
microporous
compartment
system,
microballons,
bio/muco-adhesive systems, high-density systems, and
super porous biodegradable hydro gel systems (Singh
et al., 2000). After oral administration, such a dosage
form would be retained in the stomach for several hours
and would release the drug there in a controlled and
prolonged manner, so that the drug could be supplied
continuously to its absorption sites in the upper
gastrointestinal tract (Streubel et al., 2006). Prolonged
gastric retention improves bioavailability, reduces drug
waste, and improves solubility of drugs that are less
soluble in a high pH environment. It is also suitable for
local drug delivery to the stomach and proximal small
intestine (Rao et al., 2005). Gastroretention helps to
provide better availability of new products with suitable
therapeutic activity and substantial benefits for patients.
ABBREVIATIONS: Bovine serum albumin (BSA); molar (M); ultraviolet (UV); Fourier transform infra red (FTIR); polydispersity index (PDI).
1557
2. 1558
Acyclovir, a cyclic analogue of the natural nucleoside
2-deoxyguanosine, is clinically used in the treatment of
herpes simplex, varicella zoster, cytomegalovirus, and
Epstein Barr virus infections (Brien et al., 1989).
Absorption of orally administered acyclovir is slow,
variable, and incomplete, with a bioavailability of 15%30% (Shao et al., 1994) and the elimination half-life of
acyclovir is approximately 3 hours. It has narrow
absorption window and is primarily absorbed from
stomach and upper part of the small intestine (Groning
et al., 1996); there is a need to develop an effective
formulation with enhanced gastric residence time.
Attia et al., prepared niosomes of acyclovir by using
cholesterol, span 60, and dicetyl phosphate to improve its
poor and variable bioavailability. The niosomal
dispersion when compared to the free solution has shown
more than 2-fold increase in drug bioavailability and
increase in the mean residence time of acyclovir
reflecting sustained release characteristics (Attia et al.,
2007). Palmberger et al., developed a novel oral delivery
system for the acyclovir, utilizing thiolated chitosan as
excipient, which is capable of inhibiting P-glycoprotein
(P-gp). Three chitosan-4-thiobutylamidine (Chito–TBA)
conjugates with increasing molecular mass (Chito-9.4
kDa-TBA, Chito-150 kDa-TBA, and Chito-600 kDa-TBA)
were synthesized and permeation studies on rat
intestinal mucosa and Caco-2 monolayers were
performed. They found that Chito-150 kDa–TBA/GSH
might be an appropriate sustained release drug delivery
system for acyclovir, which is able to enhance acyclovir
transport due to efflux pump inhibition (Palmberger et
al., 2008). Kharia et al., optimized the floating drug
delivery systems of acyclovir using psyllium husk and
hydroxypropylmethylcellulose K4M as the polymers by 3²
full factorial design to improve the oral bioavailability of
acyclovir. The optimized formulations followed Higuchi’s
kinetics while the drug release mechanism was found to
be anomalous type, controlled by diffusion through the
swollen matrix (Kharia et al., 2010). Stulzer et al.,
prepared microparticles containing acyclovir and
chitosan cross-linked with tripolyphosphate using the
spray-drying technique. The results obtained indicated
that the polymer/acyclovir ratio influenced the final
properties of the microparticles, with higher ratios giving
the best encapsulation efficiency, dissolution profiles,
and stability (Stulzer et al., 2009).
The aim of the present study was to formulate
gastroretentive nanoparticles of acyclovir to deliver the
drug at a controlled rate to its absorption site so that its
oral bioavailability can be enhanced. Mucoadhesive
polymers, such as bovine serum albumin, chitosan, and
gelatin, were selected to prepare gastroretentive
nanoparticles as they intensify the contact between
dosage form and the site of absorption, thereby reducing
the luminal diffusion pathway of the drug (bioadhesion)
and lead to significant improvements in oral drug
delivery (Lueben et al., 1994, Park and Robinson, 1984).
These mucoadhesive polymeric nanoparticles in the
stomach will offer various advantages such as (i) Longer
residence time of the dosage form on mucosal tissues in
Int J Pharm Sci Nanotech
Vol 4; Issue 4 • January−March 2012
the stomach. This will improve absorption of the drug
and increase the drug bioavailability. (ii) Higher drug
concentration at the site of adhesion absorption, which
will create a driving force for the paracellular passive
uptake. (iii) Immediate absorption from the bioadhesive
drug delivery system without previous dilution and
possible degradation in the luminal fluids (Hejazi and
Amiji et al., 2003)
Materials and Method
Acyclovir, bovine serum albumin (BSA), and gelatin
were obtained as a gift sample from Modern Laboratories
(Indore, India); chitosan was obtained as a gift sample
from Indian Sea Foods (Cochin, India). All other
chemicals and reagents were of laboratory grade and
were used as procured.
Preparation of Nanoparticles
Nanoparticles were prepared according to the
nanoprecipitation method with slight modification
(Elshafeey et al., 2010). Briefly, 200 mg of polymer
(bovine serum albumin, chitosan, and gelatin) was
dissolved in 25 ml of acetone separately. The acyclovir
100 mg was dissolved in 2 ml of dimethyl sulfoxide. Both
solutions were mixed and then 50 ml of water was added
and stirred for a half hour. Acetone was eliminated by
evaporation under reduced pressure using rotary flash
evaporator and the final volume of the suspension was
adjusted to 10 ml. Then this suspension was centrifuged
at 15000 rpm at 4oC for half an hour. The supernatant
was discarded and precipitate was washed 3 times with
distilled water. The nanoparticles thus obtained were
dried overnight in oven at 60ºC and stored in a
desiccator.
The prepared formulations were characterized for
loading efficiency, entrapment efficiency, particle size,
particle size distribution, polydispersity index, zeta
potential and drug excipient compatibility studies.
Characterization of Acyclovir Loaded
Nanoparticles
Loading Efficiency
Drug content in the preparation was determined by
extracting the drug from the nanoparticles with 0.1 M
hydrochloric acid. In this method, the nanoparticles (50
mg) were stirred in 50 ml of 0.1 M hydrochloric acid until
dissolved; it was filtered through a Millipore filter and
the drug content was determined, after suitable dilution,
at 254 nm by UV spectrophotometry. The loading
efficiency (L) of the nanoparticles was calculated
according to Equation 1
L (%) = (Qn /Wn) × 100
…..(1)
Where Wn is the weight of the nanoparticles and Qn
is the amount of drug present in the nanoparticles (Patel
and Patel, 2007).
3. 1559
Kharia et al: Formulation and Evaluation of Polymeric Nanoparticles of an Antiviral Drug for Gastroretention
Drug-loading and entrapment efficiency
Entrapment Efficiency
For determination of drug entrapment, the amount of
drug present in the clear supernatant after
centrifugation
was
determined
(w)
by
UV
spectrophotometer at 254 nm. A standard calibration
curve of drug was plotted for this purpose. The amount of
drug in supernatant was then subtracted from the total
amount of drug added during the preparation (W).
Effectively, (W-w) will give the amount of drug entrapped
in the particles (Bellare et al., 2005).
Then percentage entrapment of a drug was calculated
according to Equation 2
% Drug Entrapment = (W-w/W) × 100
…..(2)
Particle Size, Particle Size Distribution, and
Zeta Potential
The particle size and particle size distribution of the
formulation was determined by photo correlation
spectroscopy with a zeta master (Malvern Instruments,
UK) equipped with the Malvern PCS software. Every
sample was diluted with distilled water. The surface
charge (Zeta potential) was determined by measuring the
electrophoretic mobility of the nanoparticles using a
Malvern zeta sizer (Malvern Instruments, UK). Samples
were prepared by diluting with distilled water
(Pignatello et al., 2006).
Polydispersity Index
Polydispersity index is a parameter to define the
particle size distribution of nanoparticles obtained from
photon correlation spectroscopic analysis. It is a
dimensionless
number
extrapolated
from
the
autocorrelation function and ranges from a value of 0.01
for mono dispersed particles and up to values of 0.5-0.7.
Samples with very broad size distribution have
polydispersity index values > 0.7 (Nidhin et al., 2008).
Drug-Excipient Compatibility Studies
The drug excipient compatibility studies was
performed by using FT-IR spectrophotometer (Perkin
Elmer). The FT-IR spectra of drug, polymers, and
formulations were analyzed separately and then
correlated for incompatibility.
Results and Discussion
The method of nanoprecipitation was used so as to
avoid both chlorinated solvents and surfactants to
prevent their toxic effect on the body. All the
determinations were done in triplicate.
Although drug loading expresses the percent weight
of active ingredient encapsulated to the weight of
nanoparticles, entrapment efficiency is the ratio of the
experimentally determined percentage of drug content
compared with actual, or theoretical mass, of drug used
for the preparation of the nanoparticles. The loading
efficiency depends on the polymer-drug combination and
the method used. Hydrophobic polymers encapsulate
larger amounts of hydro phobic drugs, whereas
hydrophilic polymers entrap greater amounts of more
hydrophilic drugs. Several formulation parameters, such
as emulsifier type, weight ratio of polymer to drug, and
organic to aqueous phase ratio, will influence the extent
of drug loading.
The effect of polymer on drug loading efficiency and
entrapment efficiency are given in Table 1 and shown in
Figure 1. The values were in the range of 8.74%-17.54%
and 55.7%-74.2%, respectively. Loading efficiency was
low for gelatin and albumin nanoparticles (8.74% and
11.43%
respectively)
while
high
for
chitosan
nanoparticles (17.54%). It was found that the
entrapment efficiency were high for the formulations
containing chitosan and gelatin (73.4% and 74.2%
respectively) while low for the formulation containing
bovine serum albumin (55.7%). Loading efficiency may be
increased by increasing polymer ratio, so that sufficient
quantity of polymer will be available to entrap the drug
present in the solution, while less entrapment efficiency
may be due to hydrophilic nature of acyclovir.
Particle Size Distribution and
Polydispersity Index
The particle size and particle size distribution are
critical factors in the performance of nanoparticles, as
batches with wide particle size distribution show
significant variations in drug loading, drug release,
bioavailability, and efficacy. Particle size and particle
size distribution can be determined using light scattering
techniques and by scanning or transmission electron
microscopy. Formulation of nanoparticles with a narrow
size distribution will be a challenge if emulsion cannot be
produced with a narrow droplet size distribution. As
nanoparticles are internalized into cells by endocytosis,
an increase in particle size will decrease uptake and
potentially, affect bioavailability of the drug. The extent
of endocytosis is dependent on the type of the target cell.
TABLE 1
Drug-loading and entrapment efficiency.
Sl.
No.
Formulation
Code
Polymer
Drug:Polymer
ratio
Formulation
Code
Loading
Efficiency* ± SD %
Entrapment
Efficiency* ± SD %
1.
2.
3.
NP 1
NP 2
NP 3
Bovine Serum Albumin
Chitosan
Gelatin
1:1
1:1
1:1
NP 1
NP 2
NP 3
11.43±2
17.54±3
8.74±3
55.7±6.3
73.4±3.5
74.2±4.9
* = Average of three determinations
4. 1560
Int J Pharm Sci Nanotech
Vol 4; Issue 4 • January−March 2012
Fig. 1. Effect of polymer on loading
and entrapment efficiency.
The results of prepared nanoparticulate formulations
of acyclovir with different polymers are given in Table 2
and shown in Figure 2. The formulations had very high
polydispersity index (PDI) in the range of 0.681-1.0.
From the particle size distribution data, it is evident that
in case of BSA nanoparticles, mean particle diameter
was 250.12 nm and major portion of the particles were in
the range of 200-400 nm, for chitosan nanoparticles
mean particle diameter was 312.04 nm; and major
portion of the particles were in range of 200-525 nm. In
case of gelatin nanoparticles mean particle diameter was
743.07 nm and most of the particles were in the range of
480-1200 nm. However, in all the formulations contained
a minority population of nanoparticles in much smaller
range. For BSA, about 10.1% of the particles were in the
range 15-30 nm, for chitosan about 7.1% of the particles
were in the range 48-90 nm and for gelatin 14.1% of the
particles were in the range 70-160 nm. These minority
populations are responsible for larger over all
polydispersity indices of the formulations. We are
currently exploring the process variables affecting the
relative amounts of different populations with an
objective to increase the yield of the particles in the
smaller range to get much smaller nanoparticles, which
have
greater
degree of
monodispersity.
Such
nanoparticles can be easily separated from the larger
sized population by simple methods like filtration.
From the above data it is clear that nanoparticles
prepared by using chitosan and BSA exhibited reduction
in mean nanoparticulate diameter and narrower
granulometric distribution. But the nanoparticles
prepared using gelatin as a polymer resulted in
nanoparticulate population of large particles. The higher
particle size and polydispersity index may be because of
absence of emulsifier as the use of emulsifier decreases
the surface tension between organic phase acetone and
aqueous phase and leads to the formation of smaller
solvent droplets, which in turn causes decrease in
particle size. It also stabilizes newly generated surfaces
and prevents aggregation of the particles as reported by
previous researchers (Schubert and Muller, 2003).
Therefore results which were obtained in this study may
be improved by using increased drug:polymer ratio, using
different formulation strategy such as desolvation (for
gelatin and albumin) or counter ion induced aggregation
(for chitosan and sodium alginate), employing cross
linking agent followed by neutralizing residual cross
linking agent with cysteine and high speed stirring.
Zeta Potential
The measurement of the zeta potential allows
predictions about the storage stability of colloidal
dispersions. In general, particle aggregation is less likely
to occur for charged particles (i.e. high zeta potential)
due to electric repulsion. Generally, Zeta potential values
above 30 mV (positive or negative values) lead to more
stable nanocapsule suspensions because repulsion
between the particles prevented their aggregation. A
decrease in zeta potential, i.e. electrostatic repulsion,
was considered as the cause for the aggregation process
(Dalengon et al., 1998). The charge on the surface of the
nanospheres will influence their distribution in the body
and the extent of uptake into the cells. Because cell
membranes are negatively charged, there is greater
electrostatic affinity for positively charged nanoparticles.
Therefore, the surface of cationic or neutral
nanoparticles may be modified to confer a positive charge
to enhance efficacy.
The zeta potential values which were in the range of
–14.2 - +21.7 mV, indicates that the colloidal suspension
may not be stable and may lead to aggregation. Zeta
potential values can be altered by modifying the major
components such as surfactants, polymer, and surface
composition of the nanoparticles, the presence or the
absence of adsorbed compounds, composition of the
dispersing phase, mainly the ionic strength, and the pH
(Barratt et al., 1999).
5. 1561
Kharia et al: Formulation and Evaluation of Polymeric Nanoparticles of an Antiviral Drug for Gastroretention
during the process of formulation polymer has not
reacted with the drug to give rise to reactant products.
So it is only physical mixture and there is no interaction
between them which is in favor to proceed for
formulation.
Drug-Excipient Compatibility Studies
The results of drug-excipient compatibility studies
are shown in Table 3. From the IR data it is clear that
functionalities of drug have remained unchanged,
including intensities of the peak. This suggests that
TABLE 2
Drug polymer ratio, mean particle size, particle size distribution, poly dispersity index (PDI) and zeta potential.
Sl.
No.
Formulation
Code
Polymer
Mean Particle Size
(nm) ± SD
Size Distribution
PDI ± SD
Zeta Potential
(mV) ± SD
1.
NP 1
Bovine Serum Albumin
250.12±18
10.1% (15-30 nm)
89.9 % (200-400 nm)
1.0±0.12
21.7±1.4
2.
NP 2
Chitosan
312.04±32
7.8% (48-90 nm)
92.2% (200-525 nm)
0.681±0.15
33.2±2.1
3.
NP 3
Gelatin
743.07±45
14.2% (70-160 nm)
85.8% (480-1200 nm)
0.7770±0.14
-14.2±1.3
* = Average of three determination
Fig. 2. Effect of polymer on mean
particle size.
TABLE 3
Major peaks observed in the FT-IR spectrum.
S.
No.
1.
2.
3.
4.
5.
6.
7.
8.
Bands
-OH
N-H bend, assy.
C-C ring str.
Aromatic amines,
C-N str.
Assy. C-O-C str.
Sym C-O-C str.
N-H wagging
Mono-substitution
in ring
Drug
NP 1
cm-1
cm-1
NP 2
NP 3
cm-1
3447.8 and 3337.9
1632.5 cm-1
1537 and 1483.7 cm-1
1305.9 and 1392.1 cm-1
3442.9
1626.4 cm-1
1479.2 and 1531.1 cm-1
1387.1 cm-1
3434.5 and 3324.5
1638.8 cm-1
1456.9 cm-1
1390.4 and 1302.5 cm-1
3441.1 cm-1
1635.4 cm-1
1532.1 and 1481.1 cm-1
1303.6 cm-1
1219 cm-1
1013 cm-1
900.5 and 864.2 cm-1
777.1,753.7 and 681.2 cm-1
1216.8 cm-1
1011.9 cm-1
900.1 cm-1
767.6 and 672 cm-1
1219.2 cm-1
1080.3 cm-1
897.3 cm-1
771.5 and 675.5 cm-1
1216.5 cm-1
1011.2 cm-1
899.5 cm-1
769.8 and 670.9 cm-1
NP1 = Bovine Serum Albumin Nanoparticles, NP2 = Chitosan Nanoparticles, NP3 = Gelatin Nanoparticles
Conclusion
Among different nanoparticulate formulations
prepared by nanoprecipitation method formulation NP 2,
with chitosan in 1:1 drug: polymer ratio, showed
satisfactory results; i.e. mean particle size of 312.04 nm
(majority of the particles were in the range of 200-525
nm), polydispersity index of 0.681, zeta potential of 33.2
and loading efficiency of 17.54%, and entrapment
efficiency of 73.4%. FTIR study concluded that no major
interaction occurred between the drug and polymers used
in the present study.
6. 1562
Acknowledgements
The authors are thankful to Modern Laboratories
(Indore, India) and Indian Sea Foods (Cochin, India) for
providing gift samples and Director, Oriental College of
Pharmacy, Bhopal, India for their support and
cooperation in carrying out the research work. The
authors are very thankful to SAIL, RGPV, Bhopal, for
their valuable contribution in the determination of
particle size, PDI and zeta potential of the formulations.
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Address correspondence to: Ankit Anand Kharia, Oriental College of
Pharmacy Raisen Road, Thakral Nagar, BHOPAL (M.P.) 462021.
Mob: 09685360536; Email: ankitanandkharia@yahoo.co.in