Gastro retentive drug delivery system (GRDDS)Shweta Nehate
Oral route is the most acceptable route for drug administration. Apart from conventional dosage forms several other forms were developed in order to enhance the drug delivery for prolonged time period and for delivering drug to a particular target site. Gastro-retentive drug delivery system (GRDDS) has gainned immense popularity in the field of oral drug delivery recently. it is a widely employed approach to retain the dosage form in the stomach for an extended period of time and release the drug slowly that can address many challenges associated with conventional oral delivery, including poor bioavailability. different innovative approaches are being applied to fabricate GRDDS. Gastroretentive drug delivery is an approach to prolong gastric residence time, there by targeting site-specific drugs release in the upper gastrointestinal tract (GIT) for local or systemic effects. It is obtained by retaining dosage form into stomach and by releasing the in controlled manner.
Gastro retentive drug delivery system (GRDDS)Shweta Nehate
Oral route is the most acceptable route for drug administration. Apart from conventional dosage forms several other forms were developed in order to enhance the drug delivery for prolonged time period and for delivering drug to a particular target site. Gastro-retentive drug delivery system (GRDDS) has gainned immense popularity in the field of oral drug delivery recently. it is a widely employed approach to retain the dosage form in the stomach for an extended period of time and release the drug slowly that can address many challenges associated with conventional oral delivery, including poor bioavailability. different innovative approaches are being applied to fabricate GRDDS. Gastroretentive drug delivery is an approach to prolong gastric residence time, there by targeting site-specific drugs release in the upper gastrointestinal tract (GIT) for local or systemic effects. It is obtained by retaining dosage form into stomach and by releasing the in controlled manner.
Application Of Polymer In Controlled Release FormulationAnindya Jana
Polymers are becoming increasingly important in the field of drug delivery. The pharmaceutical applications of polymers range from their use as binders in tablets to viscosity and flow controlling agents in liquids, suspensions and emulsions. Polymers can be used as film coatings to disguise the unpleasant taste of a drug, to enhance drug stability and to modify drug release characteristics.
As a consequence, increasing attention has been focused on methods of giving drugs continually for a prolonged time periods and in a controlled fashion.
This technology now spans many fields and includes pharmaceutical, food and agricultural applications, pesticides, cosmetics, and household products.
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 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.
Mucoadhesive drug delivery system interact with the mucus layer covering the mucosal epithelial surface, & mucin molecules & increase the residence time of the dosage form at the site of the absorption.
Mucoadhesive drug delivery system is a part of controlled delivery system.
Since the early 1980,the concept of Mucoadhesion has gained considerable interest in pharmaceutical technology.
combine mucoadhesive with enzyme inhibitory & penetration enhancer properties & improve the patient complaince.
MDDS have been devloped for buccal ,nasal,rectal &vaginal routes for both systemic & local effects.
Hydrophilic high mol. wt. such as peptides that cannot be administered & poor absorption ,then MDDS is best choice.
Mucoadhesiveinner layers called mucosa inner epithelial cell lining is covered with viscoelasticfluid
Composed of water and mucin.
Thickness varies from 40 μm to 300 μm
General composition of mucus
Water…………………………………..95%
Glycoproteinsand lipids……………..0.5-5%
Mineral salts……………………………1%
Free proteins…………………………..0.5-1%
The mechanism responsible in the formation of mucoadhesive bond
Step 1 : Wetting and swelling of the polymer(contact stage)
Step 2 : Interpenetration between the polymer chains and the mucosal membrane
Step 3 : Formation of bonds between the entangled chains (both known as consolidation stage)
Electronic theory
Wetting theory
Adsorption theory
Diffusion theory
Fracture theory
Advantages over other controlled oral controlled release systems by virtue of prolongation of residence of drug in GIT.
Targeting & localization of the dosage form at a specific site
-Painless administration.
-Low enzymatic activity & avoid of first pass metabolism
If MDDS are adhere too tightlgy because it is undesirable to exert too much force to remove the formulation after use,otherwise the mucosa could be injured.
-Some patient suffers unpleasent feeling.
-Unfortunately ,the lack of standardized techniques often leads to unclear results.
-costly drug delivery system
Video Lecture is available at https://www.youtube.com/watch?v=DXu_CLgB4q0
Introduction, terminology/definitions and rationale, advantages, disadvantages, selection of drug candidates. Approaches to design-controlled release formulations based on diffusion, dissolution and ion exchange principles. Physicochemical and
biological properties of drugs relevant to controlled release formulations.
Application Of Polymer In Controlled Release FormulationAnindya Jana
Polymers are becoming increasingly important in the field of drug delivery. The pharmaceutical applications of polymers range from their use as binders in tablets to viscosity and flow controlling agents in liquids, suspensions and emulsions. Polymers can be used as film coatings to disguise the unpleasant taste of a drug, to enhance drug stability and to modify drug release characteristics.
As a consequence, increasing attention has been focused on methods of giving drugs continually for a prolonged time periods and in a controlled fashion.
This technology now spans many fields and includes pharmaceutical, food and agricultural applications, pesticides, cosmetics, and household products.
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 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.
Mucoadhesive drug delivery system interact with the mucus layer covering the mucosal epithelial surface, & mucin molecules & increase the residence time of the dosage form at the site of the absorption.
Mucoadhesive drug delivery system is a part of controlled delivery system.
Since the early 1980,the concept of Mucoadhesion has gained considerable interest in pharmaceutical technology.
combine mucoadhesive with enzyme inhibitory & penetration enhancer properties & improve the patient complaince.
MDDS have been devloped for buccal ,nasal,rectal &vaginal routes for both systemic & local effects.
Hydrophilic high mol. wt. such as peptides that cannot be administered & poor absorption ,then MDDS is best choice.
Mucoadhesiveinner layers called mucosa inner epithelial cell lining is covered with viscoelasticfluid
Composed of water and mucin.
Thickness varies from 40 μm to 300 μm
General composition of mucus
Water…………………………………..95%
Glycoproteinsand lipids……………..0.5-5%
Mineral salts……………………………1%
Free proteins…………………………..0.5-1%
The mechanism responsible in the formation of mucoadhesive bond
Step 1 : Wetting and swelling of the polymer(contact stage)
Step 2 : Interpenetration between the polymer chains and the mucosal membrane
Step 3 : Formation of bonds between the entangled chains (both known as consolidation stage)
Electronic theory
Wetting theory
Adsorption theory
Diffusion theory
Fracture theory
Advantages over other controlled oral controlled release systems by virtue of prolongation of residence of drug in GIT.
Targeting & localization of the dosage form at a specific site
-Painless administration.
-Low enzymatic activity & avoid of first pass metabolism
If MDDS are adhere too tightlgy because it is undesirable to exert too much force to remove the formulation after use,otherwise the mucosa could be injured.
-Some patient suffers unpleasent feeling.
-Unfortunately ,the lack of standardized techniques often leads to unclear results.
-costly drug delivery system
Video Lecture is available at https://www.youtube.com/watch?v=DXu_CLgB4q0
Introduction, terminology/definitions and rationale, advantages, disadvantages, selection of drug candidates. Approaches to design-controlled release formulations based on diffusion, dissolution and ion exchange principles. Physicochemical and
biological properties of drugs relevant to controlled release formulations.
GRDDS is most widely used system for controlled delivery of drugs. various approaches for GRDDS is available including
floating ,gastroadhesive,high density ,unflatable system
Gastroretentive drug delivery is an approach to
prolong gastric residence time, thereby
targeting site-specific drug release in the upper
gastrointestinal tract (GIT) for local or
systemic effects. The various approaches are discussed with advantages like sustained drug delivery, increased bioavailability and site specific drug delivery.
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdfJim Jacob Roy
Cardiac conduction defects can occur due to various causes.
Atrioventricular conduction blocks ( AV blocks ) are classified into 3 types.
This document describes the acute management of AV block.
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
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Gastrorentive drug delivery systems
1. GASTRO RETENTIVE DRUG DELIVERY
SYSTEM - ADVANTAGES, LIMITATIONS AND
DIFFERENT APPROACHES
Dr.K.Umasankar.,M.Pharm.,Ph.D.,FAGE
Krishna Teja Pharmacy College
Tirupathi
Email:- umasankar73@gmail.com
1
3. INTRODUCTION
• Oral Drug Delivery is widely used in pharmaceutical field to treat the diseases.
• Some drugs are absorbed at specific site only these require release at that
specific site.
• Gastro Retentive Drug Delivery(GRDDS) is one of the site specific drug
delivery for the delivery of the drugs at stomach.
• Retaining the Dosage Form in stomach and drug is being released at
controlled manner at specific site
3
4. APPROPRIATE CANDIDATE DRUGS FOR GRDDS
• Drugs - acting locally in the stomach.
E.g. Antacids and drugs for H. Pylori viz.,
Misoprostol.
• Drugs - primarily absorbed in the stomach.
E.g. Amoxicillin
• Drugs - poorly soluble at alkaline pH.
E.g. Furosamide, Diazepam, Verapamil, etc.
• Drugs - with a narrow absorption window.
E.g. Cyclosporine, , Levodopa, Methotrexate etc.
•
Drugs - absorbed rapidly from the GI tract.
E.g. Metronidazole, tetracycline.
• Drugs that degrade in the colon.
E.g. Ranitidine, Metformin.
• Drugs that disturb normal colonic microbes
E.g. antibiotics against Helicobacter pylori.
4
5. ADVANTAGES
Enhanced bioavailability
Sustained drug delivery/reduced frequency
of Dosing
Targeted therapy for local ailments in the
upper GIT
Reduced fluctuations of drug concentration
Improved selectivity in receptor activation
Reduced counter-activity of the body
Extended effective concentration.
Minimized adverse activity at the colon.
5
6. LIMITATIONS
The drug substances that are unstable in the acidic environment of the
stomach are not suitable candidates to be incorporated in the systems.
These systems require a high level of fluid in the stomach for drug delivery to
float and work efficiently.
Not suitable for drugs that have solubility or stability problem in GIT.
Drugs which are irritant to gastric mucosa are also not suitable
These systems do not offer significant advantages over the conventional dosage
forms for drugs, which are absorbed throughout GIT.
6
7. APPROACHES FOR PROLONGING THE
GASTRIC RESIDENCE TIME
High-density systems. (HDS)
•
Floating systems. (FS)
•
Swelling and expanding
S
S
A
S
•
F
S
HDS
systems. (SS)
•
Mucoadhesive & Bioadhesive
systems. (AS)
7
9. HIGH DENSITY SYSTEM
• Gastric contents have a density close to water (1.004 g cm−3). When
the patient take high-density pellets, they sink to the bottom of the
stomach where they become entrapped in the folds of the antrum
and withstand the peristaltic waves of the stomach wall.
• A density close to 2.5 g cm−3 seems necessary for significant
prolongation of gastric residence time.
• Barium sulphate, zinc oxide, iron powder, and titanium dioxide
are examples for excipients used.
9
10. FLOATING DRUG DELIVERY
These have a bulk density lower than the gastric content. They remain buoyant in the
stomach for a prolonged period of time, with the potential for continuous release of drug.
They Include:
Hydrodynamically balanced systems (HBS)
Gas-generating systems
Volatile liquid/ vacuum containing systems
Raft-forming systems
Low-density systems
10
11. GAS GENERATING SYSTEMS
• Carbonates or bicarbonates, which react with
gastric acid or any other acid (e.g., citric or
tartaric) present in the formulation to produce
CO 2 , are usually incorporated in the dosage
form, thus reducing the density of the system
and making it float on the media.
11
12. MATRIX TABLETS
Single layer matrix tablet is prepared by
incorporating bicarbonates in matrix forming
hydrocolloid gelling agent like HPMC, Chitosin,
Alginate or other polymers and drug.
Bilayer tablet can also be prepared by gas
generating matrix in one layer and second layer
with drug for its SR effect.
Triple layer tablet also prepared having first
swellable floating layer with bicarbonates, second
sustained release layer of drug and third rapid
dissolving layer of bismuth salt.
12
13. INFLATABLE GASTROINTESTINAL DELIVERY
•
System is incorporated with an inflatable
chamber which contains liquid ether - gasifies
at body temperature to cause the chamber to
inflate in stomach.
•
Inflatable chamber is loaded with a drug
reservoir which can be a drug, impregnated
polymeric then encapsulated
in a gelatin capsule.
13
14. INTRAGASTRIC OSMOTICALLY CONTROLLED DDS
Comprised of both an osmotic pressure controlled drug delivery device and an
inflatable floating support in a biodegradable capsule.
In stomach, the capsule quickly disintegrates and release the intragastric
osmotically controlled drug delivery device.
Inflatable support forms a deformable hollow polymeric bag containing liquid
that gasifies at body temperature to inflate the bag.
Consists of 2 compartments:
•
Drug reservoir
•
Osmotically active compartment.
14
15. INTRA-GASTRIC FLOATING
GASTROINTESTINAL DRUG DELIVERY
SYSTEMS
System can be float by flotation chamber, which may be vacuum or
filled with air or a harmless gas
Drug reservoir is
encapsulated inside
a microporous
compartment
15
16. HYDRODYNAMICALLY BALANCED SYSYTEMS
Prepared by incorporating a high level (20-75%w/w) gel-forming
hydrocolloids. e.g.:- Hydoxyethylcellulose, hydroxypropylcellulose,
HPMC & Sod. CMC into the formulation and then compressing these
granules into a tablets or capsules.
It maintains the bulk density less than 1.
16
17. RAFT FORMING SYSTEM
This system is used for delivery of antacids and drug delivery for treatment of
gastrointestinal infections and disorders.
The mechanism involved in this system includes the formation of a viscous cohesive
gel in contact with gastric fluids, forming a continuous layer called raft.
17
18. HOLLOW MICROSPHERES
Polymers used commonly: Polycarbonates, Cellulose acetate, Calcium alginate,
Eudragit S, agar and methoxylated pectin etc.
18
19. ALGINATE BEADS
• Prepared by dropping
sodium alginate
solution into aqueous
solution of calcium
chloride, causing the
precipitation of calcium
alginate
• Freeze dry in liquid
nitrogen at -40 o c for
24h.
• Beads-spherical and
2.5 mm in diameter.
SUPERPOROUS HYDROGELS
Swellable agents have pore
size ranging between 10nm
to 10µm.
Superporous hydrogels will
swell more than the swelling
ratio 100,
This is achieved by coformulation of a hydrophilic
particulate material, and AcDi-Sol (crosscarmellose).
19
20. EXPANDABLE SYSTEMS
1.UNFOLDED SYSTEMS
2.SWELLABLE SYSTEMS
The swelling is usually results
from osmotic absorption of
water.
The device gradually
decreases in volume and
rigidity as a result depletion of
drug and expanding agent
and/or bioerosion of polymer
layer, enabling its elimination.
20
21. MUCOADHESIVE SYSTEMS
• The basis of mucoadhesion is that a dosage form can stick
to the mucosal surface by different mechanisms.
• Examples for Materials commonly used for bioadhesion are
poly (acrylic acid) (Carbopol®, polycarbophil), chitosin,
Gantrez® (Polymethyl vinyl ether/maleic anhydride
copolymers), cholestyramine, tragacanth, sodium alginate
21
22. MAGNETIC SYSTEM
Based upon the principle that dosage form contains
a small internal magnet, and a magnet placed on the
abdomen over the position of stomach can enhance
the GRT.
22
23. Marketed Products of GRDDS
Brand name
Delivery system
Drug (dose)
Company
name
Valrelease®
Floating capsule
Diazepam (15mg)
Hoffmann-LaRoche,
USA
Madopar® HBS
(Prolopa® HBS)
Floating, CR capsule
Benserazide (25mg) and Ldopa (100mg)
Roche Products,
USA
Liquid Gaviscon®
Effervescent Floating
liquid alginate
preparations
Al hydroxide (95 mg), Mg
Carbonate (358 mg)
GlaxoSmithkline,
India
Topalkan®
Floating liquid alginate
Preparation
Al – Mg antacid
Pierre Fabre Drug,
France
Conviron®
Colloidal gel forming
FDDS
Ferrous sulphate
Ranbaxy, India
Cytotech®
Bilayer floating capsule
Misoprostol (100μg/200μg)
Pharmacia, USA
Cifran OD®
Gas-generating floating
form
Ciprofloxacin (1gm)
Ranbaxy, India
23
24. CONCLUSION
• Gastro retentive drug delivery systems have
emerged as a current approach of controlled
delivery of drugs that exhibit an absorption window .
• All these drug delivery systems have their own
advantages and drawbacks.
• To design a successful GRDDS, it is necessary to
take into consideration the physicochemical
properties of the drug, physiological events in the
GIT, formulation strategies, and correct combination
of drug and excipients.
24