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.
The document discusses ocular drug delivery systems. It begins by introducing the need for ocular drug delivery and some of the challenges, such as short residence time of eye drops. It then covers eye anatomy and factors affecting drug absorption. Various traditional and advanced ocular drug delivery systems are described, including solutions, suspensions, inserts, nanoparticles, and hydrogels. The mechanisms of drug release and factors influencing performance of these systems are also summarized. Evaluation methods for ocular formulations include assessing drug content, moisture absorption, and in vitro drug release using methods like the bottle or diffusion cell techniques.
The document discusses gastroretentive drug delivery systems which are designed to prolong the gastric residence time of drugs and promote local or systemic drug delivery in the upper gastrointestinal tract. It describes the anatomy of the stomach and its different regions. It also discusses the different motility phases of the stomach and how gastroretentive systems can provide benefits like improved drug absorption and bioavailability, reduced dosing frequency, and site-specific drug targeting in the stomach. Various types of gastroretentive drug delivery systems are also summarized, including floating, swelling/expanding, bioadhesive, high density, and raft forming systems. Evaluation parameters for floating and swelling systems are also highlighted.
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.
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 concentric phospholipid bilayers that were first produced in 1961 and can be used to deliver drugs. They range in size from 20nm to several micrometers and are made up of phospholipids that form a bilayer with a hydrophilic exterior and hydrophobic interior. Liposomes offer advantages for drug delivery such as targeting drugs to specific tissues, increasing drug stability and reducing toxicity.
This document discusses monoclonal antibodies (mAbs), which are antibodies that are cloned from identical immune cells. mAbs are produced using hybridoma technology, which involves fusing antibody-producing immune cells with myeloma cells to produce immortal hybrid cell lines. These hybridomas can then be cultured to mass-produce mAbs with a single specificity. The document outlines the history, properties, production process including immunization, cell fusion and screening, and applications of mAbs in diagnostics and therapeutics. Specific examples of therapeutic mAbs are also provided.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate water-soluble or lipid-soluble drugs. They provide targeted drug delivery and increase drug efficacy while reducing toxicity. Liposomes are classified by lamellarity and size, and are characterized based on their physical properties. They have various applications including cancer therapy, gene delivery, and treatment of infections.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate hydrophilic or hydrophobic drugs. They range in size from 25nm to 5000nm. This document discusses the structure of liposomes and their components, including phospholipids and cholesterol. It also covers various preparation methods such as lipid film hydration, extrusion, and detergent removal. Liposomes offer advantages for drug delivery such as the ability to encapsulate different drug types and provide controlled release, but also have challenges like high production costs and drug leakage.
The document discusses ocular drug delivery systems. It begins by introducing the need for ocular drug delivery and some of the challenges, such as short residence time of eye drops. It then covers eye anatomy and factors affecting drug absorption. Various traditional and advanced ocular drug delivery systems are described, including solutions, suspensions, inserts, nanoparticles, and hydrogels. The mechanisms of drug release and factors influencing performance of these systems are also summarized. Evaluation methods for ocular formulations include assessing drug content, moisture absorption, and in vitro drug release using methods like the bottle or diffusion cell techniques.
The document discusses gastroretentive drug delivery systems which are designed to prolong the gastric residence time of drugs and promote local or systemic drug delivery in the upper gastrointestinal tract. It describes the anatomy of the stomach and its different regions. It also discusses the different motility phases of the stomach and how gastroretentive systems can provide benefits like improved drug absorption and bioavailability, reduced dosing frequency, and site-specific drug targeting in the stomach. Various types of gastroretentive drug delivery systems are also summarized, including floating, swelling/expanding, bioadhesive, high density, and raft forming systems. Evaluation parameters for floating and swelling systems are also highlighted.
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.
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 concentric phospholipid bilayers that were first produced in 1961 and can be used to deliver drugs. They range in size from 20nm to several micrometers and are made up of phospholipids that form a bilayer with a hydrophilic exterior and hydrophobic interior. Liposomes offer advantages for drug delivery such as targeting drugs to specific tissues, increasing drug stability and reducing toxicity.
This document discusses monoclonal antibodies (mAbs), which are antibodies that are cloned from identical immune cells. mAbs are produced using hybridoma technology, which involves fusing antibody-producing immune cells with myeloma cells to produce immortal hybrid cell lines. These hybridomas can then be cultured to mass-produce mAbs with a single specificity. The document outlines the history, properties, production process including immunization, cell fusion and screening, and applications of mAbs in diagnostics and therapeutics. Specific examples of therapeutic mAbs are also provided.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate water-soluble or lipid-soluble drugs. They provide targeted drug delivery and increase drug efficacy while reducing toxicity. Liposomes are classified by lamellarity and size, and are characterized based on their physical properties. They have various applications including cancer therapy, gene delivery, and treatment of infections.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate hydrophilic or hydrophobic drugs. They range in size from 25nm to 5000nm. This document discusses the structure of liposomes and their components, including phospholipids and cholesterol. It also covers various preparation methods such as lipid film hydration, extrusion, and detergent removal. Liposomes offer advantages for drug delivery such as the ability to encapsulate different drug types and provide controlled release, but also have challenges like high production costs and drug leakage.
Vesicles are colloidal particles in which a concentric bilayer made-up of amphiphilic molecules surrounds an aqueous compartment Useful vehicle for drug delivery of both hydrophobic drugs and hydrophilic drugs, which are encapsulated in the interior aqueous compartment.
Liposomal drug delivery involves encapsulating drugs within liposomes, which are spherical vesicles composed of phospholipid bilayers, to improve drug targeting and reduce toxicity. Liposomes can be classified based on lamellarity, size, and method of preparation. Drugs are encapsulated within the aqueous interior or phospholipid bilayer of liposomes. Liposomes protect drugs, control drug release, and can be targeted to specific tissues. Applications include cancer therapy, antimicrobial delivery, ophthalmic delivery, and topical delivery to improve treatment.
Nanoparticle targeted drug delivery systemBINDIYA PATEL
This document discusses nanoparticles as subnanosized colloidal drug delivery systems ranging from 10-1000 nm in diameter. It defines nanoparticles and describes their basic concept of selectively delivering drugs to target tissues while restricting access to non-target tissues. The document outlines ideal characteristics of nanoparticles and various methods for their preparation, characterization, and evaluation. It provides examples of nanoparticle applications such as cancer therapy, intracellular targeting, vaccines, DNA delivery, and ocular delivery. The document concludes by listing references for further information on nanoparticles.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate hydrophilic or hydrophobic drugs. There are several methods for manufacturing liposomes including mechanical dispersion methods like film hydration and sonication. Film hydration involves dissolving lipids in an organic solvent to form a thin film, removing the solvent, then hydrating the film. The hydrated lipid sheets self-close to form multilamellar vesicles. Several factors must be considered for liposome preparation including lipid selection, phase transition temperature, charge, and cholesterol content. Liposomes can be classified based on size, lamellarity, surface properties, and method of preparation.
This document discusses polymeric micelles, which are self-assembled colloidal particles composed of amphiphilic block copolymers. It covers the mechanism of micelle formation, factors affecting micellization, types of polymeric micelles including conventional, poly-ion complex, and non-covalently connected micelles. Methods for preparing polymeric micelles include direct dissolution, solvent casting, dialysis, and lyophilization. Key characteristics include the critical micelle concentration and size/shape as determined by light scattering and microscopy. Applications include solubilization of hydrophobic drugs and targeted drug delivery.
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.
liposomes are novel drug delivery dosage systems, where the drug is entrapped in phospholipid bilayered vesicles. the release of drug from the vesicles can be controlled or sustained.
the follwing presentation contain structure, classification and preparation methods, characterization and applications of liposomes.
Oral sustained and controlled release dosage forms Dr Gajanan Sanap
This document discusses oral sustained and controlled release dosage forms. It begins with an introduction and overview of rationality in designing sustained release drug formulations. It defines sustained release as formulations that continuously release medication over an extended period after a single dose to achieve prolonged therapeutic effects. Controlled release aims to deliver drug at a predetermined rate for a specified time period to maintain constant drug levels. The document outlines the differences between controlled and sustained release. It discusses objectives and advantages of sustained release formulations as well as challenges and factors to consider in design.
This document provides an overview of a seminar presentation on liposomes. It begins with an introduction defining liposomes as vesicles with an aqueous volume enclosed by a phospholipid bilayer. It then discusses the composition of liposomes, including the structure of phospholipids. Various methods for preparing liposomes are described, such as mechanical dispersion, freeze drying, sonication, and microemulsification. Liposomes can be classified based on their structure, preparation method, or composition. The document concludes by discussing techniques for characterizing liposomes, including evaluating their physical properties like size, surface charge, and drug encapsulation efficiency.
Nanostructured lipid carriers (NLCs) were presented as a topical drug delivery system. NLCs consist of a blend of solid and liquid lipids which can incorporate drugs at high loading capacities. They were summarized to have advantages over solid lipid nanoparticles including avoidance of drug expulsion and unpredictable gelation. Methods for producing NLCs like high pressure homogenization were described. NLCs were said to increase skin permeation of drugs while providing occlusive and moisturizing properties beneficial for skin care. Several drug-loaded NLC formulations were presented including ones for flurbiprofen, minoxidil, and tacrolimus to improve their topical delivery and stability.
Liposomes and liposomal drug delivery system( recent advancement)Unmesh Bhamare
This document summarizes a seminar presentation on recent trends in pharmaceutical sciences focusing on liposomes. It defines liposomes as concentric bilayered vesicles enclosing an aqueous volume within a phospholipid membrane. The presentation covers the structural components of liposomes including commonly used phospholipids, classification based on lamellarity and size, various preparation methods such as mechanical dispersion, solvent dispersion, and detergent removal. It also discusses characterization, stability considerations, applications in drug delivery, recent advances, and some marketed liposome products.
Liposomes are spherical vesicles composed of a lipid bilayer membrane enclosing an aqueous core. They can encapsulate both hydrophilic and hydrophobic drugs. Liposomes offer several advantages for drug delivery such as increased drug efficacy, reduced toxicity, and ability to target specific tissues. They are classified based on lamellarity and size. Common preparation methods include thin film hydration, reverse phase evaporation, and detergent removal. Key properties evaluated include particle size, surface charge, drug encapsulation efficiency, and drug release kinetics. Liposomes have applications as carriers for drugs, proteins, genes, and imaging agents.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate hydrophilic or hydrophobic drugs. They range in size from 25nm to 5000nm. This document discusses the structure of liposomes and their components, including phospholipids and cholesterol. Various preparation methods are described, such as lipid film hydration, ethanol injection, and detergent removal. Liposomes offer advantages for drug delivery, such as the ability to encapsulate different drug types and provide controlled release. They can be classified based on structure, method of preparation, composition, and specialty type.
Liposome drug delivery is a promising approach for ophthalmic applications. Liposomes can encapsulate both hydrophilic and hydrophobic drugs, protecting them from degradation and increasing ocular bioavailability. They have intimate contact with the cornea and conjunctiva, enhancing residence time for poorly absorbed drugs. Liposomal formulations can also reduce drug toxicity and provide sustained release at target sites in the eye. Examples include reducing toxicity of amphotericin B and improving pharmacokinetics of fluconazole and ciprofloxacin for ocular diseases.
Liposomes are spherical vesicles made of concentric phospholipid bilayers that can encapsulate drugs. They were discovered in the 1960s and have been widely explored as a drug delivery system. Liposomes allow targeted delivery, extended release, and protection of drugs. They can encapsulate both water-soluble drugs within the aqueous core and lipid-soluble drugs within the bilayer. Liposomes are characterized based on size, surface charge, lamellarity, drug encapsulation efficiency, and release kinetics. They have applications in drug, gene, vaccine and enzyme delivery.
Niosomes are non-ionic surfactant-based vesicles that can be used to deliver drugs. They are divided into small unilamellar vesicles, large unilamellar vesicles, and multi-lamellar vesicles based on their size and number of bilayers. Niosomes can be used for controlled drug release, to improve drug stability and bioavailability, and for targeted drug delivery to tissues like the liver, spleen, and tumors. They have applications in drug delivery via various routes of administration like oral, topical, and intravenous delivery.
This document discusses various techniques for preparing and characterizing liposomes. It describes common methods for passive loading of drugs into liposomes, such as freeze drying, ethanol injection, ether injection, and reverse-phase evaporation. It also discusses remote loading using pH gradients or electrical potentials. Characterization techniques discussed include measuring particle size, surface charge, drug encapsulation efficiency, transition temperature, and drug release rate. Methods are provided for determining important chemical characteristics like phospholipid and cholesterol content.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate aqueous solutions. They come in several sizes and lamellar structures. Liposomes are prepared through mechanical dispersion and processing of hydrated lipids. They can be purified through gel filtration, dialysis, or centrifugation. Liposomes can encapsulate and deliver drugs while protecting them from degradation and increasing their half-life. They can also be targeted to specific tissues and used for sustained drug release.
Liposomes, Structure of liposome, phospholipids, classification of liposomes, method of preparation of liposomes, mechanism of liposome formation, application of liposomes.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate aqueous solutions. They range in size from 20nm to several microns. Liposomes can be used to deliver drugs as they protect drugs from degradation and can target delivery to specific tissues. There are several types of liposomes classified by their structure, size, number of bilayers, and method of preparation. The main components used to form liposome bilayers are phospholipids like phosphatidylcholine and cholesterol. Liposomes offer advantages for drug delivery such as passive targeting to tumors, reduced toxicity, and improved pharmacokinetics.
This document provides information on liposomes, including:
- Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate drugs. They were first demonstrated in 1965.
- Liposomes offer advantages for drug delivery such as the ability to encapsulate both hydrophilic and hydrophobic drugs and provide controlled release.
- Liposomes are classified based on size, lamellarity, and composition. Common types include small unilamellar vesicles, multilamellar large vesicles, and long-circulating stealth liposomes.
- Drugs can be loaded into liposomes using passive loading techniques like mechanical dispersion or solvent dispersion methods.
Vesicles are colloidal particles in which a concentric bilayer made-up of amphiphilic molecules surrounds an aqueous compartment Useful vehicle for drug delivery of both hydrophobic drugs and hydrophilic drugs, which are encapsulated in the interior aqueous compartment.
Liposomal drug delivery involves encapsulating drugs within liposomes, which are spherical vesicles composed of phospholipid bilayers, to improve drug targeting and reduce toxicity. Liposomes can be classified based on lamellarity, size, and method of preparation. Drugs are encapsulated within the aqueous interior or phospholipid bilayer of liposomes. Liposomes protect drugs, control drug release, and can be targeted to specific tissues. Applications include cancer therapy, antimicrobial delivery, ophthalmic delivery, and topical delivery to improve treatment.
Nanoparticle targeted drug delivery systemBINDIYA PATEL
This document discusses nanoparticles as subnanosized colloidal drug delivery systems ranging from 10-1000 nm in diameter. It defines nanoparticles and describes their basic concept of selectively delivering drugs to target tissues while restricting access to non-target tissues. The document outlines ideal characteristics of nanoparticles and various methods for their preparation, characterization, and evaluation. It provides examples of nanoparticle applications such as cancer therapy, intracellular targeting, vaccines, DNA delivery, and ocular delivery. The document concludes by listing references for further information on nanoparticles.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate hydrophilic or hydrophobic drugs. There are several methods for manufacturing liposomes including mechanical dispersion methods like film hydration and sonication. Film hydration involves dissolving lipids in an organic solvent to form a thin film, removing the solvent, then hydrating the film. The hydrated lipid sheets self-close to form multilamellar vesicles. Several factors must be considered for liposome preparation including lipid selection, phase transition temperature, charge, and cholesterol content. Liposomes can be classified based on size, lamellarity, surface properties, and method of preparation.
This document discusses polymeric micelles, which are self-assembled colloidal particles composed of amphiphilic block copolymers. It covers the mechanism of micelle formation, factors affecting micellization, types of polymeric micelles including conventional, poly-ion complex, and non-covalently connected micelles. Methods for preparing polymeric micelles include direct dissolution, solvent casting, dialysis, and lyophilization. Key characteristics include the critical micelle concentration and size/shape as determined by light scattering and microscopy. Applications include solubilization of hydrophobic drugs and targeted drug delivery.
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.
liposomes are novel drug delivery dosage systems, where the drug is entrapped in phospholipid bilayered vesicles. the release of drug from the vesicles can be controlled or sustained.
the follwing presentation contain structure, classification and preparation methods, characterization and applications of liposomes.
Oral sustained and controlled release dosage forms Dr Gajanan Sanap
This document discusses oral sustained and controlled release dosage forms. It begins with an introduction and overview of rationality in designing sustained release drug formulations. It defines sustained release as formulations that continuously release medication over an extended period after a single dose to achieve prolonged therapeutic effects. Controlled release aims to deliver drug at a predetermined rate for a specified time period to maintain constant drug levels. The document outlines the differences between controlled and sustained release. It discusses objectives and advantages of sustained release formulations as well as challenges and factors to consider in design.
This document provides an overview of a seminar presentation on liposomes. It begins with an introduction defining liposomes as vesicles with an aqueous volume enclosed by a phospholipid bilayer. It then discusses the composition of liposomes, including the structure of phospholipids. Various methods for preparing liposomes are described, such as mechanical dispersion, freeze drying, sonication, and microemulsification. Liposomes can be classified based on their structure, preparation method, or composition. The document concludes by discussing techniques for characterizing liposomes, including evaluating their physical properties like size, surface charge, and drug encapsulation efficiency.
Nanostructured lipid carriers (NLCs) were presented as a topical drug delivery system. NLCs consist of a blend of solid and liquid lipids which can incorporate drugs at high loading capacities. They were summarized to have advantages over solid lipid nanoparticles including avoidance of drug expulsion and unpredictable gelation. Methods for producing NLCs like high pressure homogenization were described. NLCs were said to increase skin permeation of drugs while providing occlusive and moisturizing properties beneficial for skin care. Several drug-loaded NLC formulations were presented including ones for flurbiprofen, minoxidil, and tacrolimus to improve their topical delivery and stability.
Liposomes and liposomal drug delivery system( recent advancement)Unmesh Bhamare
This document summarizes a seminar presentation on recent trends in pharmaceutical sciences focusing on liposomes. It defines liposomes as concentric bilayered vesicles enclosing an aqueous volume within a phospholipid membrane. The presentation covers the structural components of liposomes including commonly used phospholipids, classification based on lamellarity and size, various preparation methods such as mechanical dispersion, solvent dispersion, and detergent removal. It also discusses characterization, stability considerations, applications in drug delivery, recent advances, and some marketed liposome products.
Liposomes are spherical vesicles composed of a lipid bilayer membrane enclosing an aqueous core. They can encapsulate both hydrophilic and hydrophobic drugs. Liposomes offer several advantages for drug delivery such as increased drug efficacy, reduced toxicity, and ability to target specific tissues. They are classified based on lamellarity and size. Common preparation methods include thin film hydration, reverse phase evaporation, and detergent removal. Key properties evaluated include particle size, surface charge, drug encapsulation efficiency, and drug release kinetics. Liposomes have applications as carriers for drugs, proteins, genes, and imaging agents.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate hydrophilic or hydrophobic drugs. They range in size from 25nm to 5000nm. This document discusses the structure of liposomes and their components, including phospholipids and cholesterol. Various preparation methods are described, such as lipid film hydration, ethanol injection, and detergent removal. Liposomes offer advantages for drug delivery, such as the ability to encapsulate different drug types and provide controlled release. They can be classified based on structure, method of preparation, composition, and specialty type.
Liposome drug delivery is a promising approach for ophthalmic applications. Liposomes can encapsulate both hydrophilic and hydrophobic drugs, protecting them from degradation and increasing ocular bioavailability. They have intimate contact with the cornea and conjunctiva, enhancing residence time for poorly absorbed drugs. Liposomal formulations can also reduce drug toxicity and provide sustained release at target sites in the eye. Examples include reducing toxicity of amphotericin B and improving pharmacokinetics of fluconazole and ciprofloxacin for ocular diseases.
Liposomes are spherical vesicles made of concentric phospholipid bilayers that can encapsulate drugs. They were discovered in the 1960s and have been widely explored as a drug delivery system. Liposomes allow targeted delivery, extended release, and protection of drugs. They can encapsulate both water-soluble drugs within the aqueous core and lipid-soluble drugs within the bilayer. Liposomes are characterized based on size, surface charge, lamellarity, drug encapsulation efficiency, and release kinetics. They have applications in drug, gene, vaccine and enzyme delivery.
Niosomes are non-ionic surfactant-based vesicles that can be used to deliver drugs. They are divided into small unilamellar vesicles, large unilamellar vesicles, and multi-lamellar vesicles based on their size and number of bilayers. Niosomes can be used for controlled drug release, to improve drug stability and bioavailability, and for targeted drug delivery to tissues like the liver, spleen, and tumors. They have applications in drug delivery via various routes of administration like oral, topical, and intravenous delivery.
This document discusses various techniques for preparing and characterizing liposomes. It describes common methods for passive loading of drugs into liposomes, such as freeze drying, ethanol injection, ether injection, and reverse-phase evaporation. It also discusses remote loading using pH gradients or electrical potentials. Characterization techniques discussed include measuring particle size, surface charge, drug encapsulation efficiency, transition temperature, and drug release rate. Methods are provided for determining important chemical characteristics like phospholipid and cholesterol content.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate aqueous solutions. They come in several sizes and lamellar structures. Liposomes are prepared through mechanical dispersion and processing of hydrated lipids. They can be purified through gel filtration, dialysis, or centrifugation. Liposomes can encapsulate and deliver drugs while protecting them from degradation and increasing their half-life. They can also be targeted to specific tissues and used for sustained drug release.
Liposomes, Structure of liposome, phospholipids, classification of liposomes, method of preparation of liposomes, mechanism of liposome formation, application of liposomes.
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate aqueous solutions. They range in size from 20nm to several microns. Liposomes can be used to deliver drugs as they protect drugs from degradation and can target delivery to specific tissues. There are several types of liposomes classified by their structure, size, number of bilayers, and method of preparation. The main components used to form liposome bilayers are phospholipids like phosphatidylcholine and cholesterol. Liposomes offer advantages for drug delivery such as passive targeting to tumors, reduced toxicity, and improved pharmacokinetics.
This document provides information on liposomes, including:
- Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate drugs. They were first demonstrated in 1965.
- Liposomes offer advantages for drug delivery such as the ability to encapsulate both hydrophilic and hydrophobic drugs and provide controlled release.
- Liposomes are classified based on size, lamellarity, and composition. Common types include small unilamellar vesicles, multilamellar large vesicles, and long-circulating stealth liposomes.
- Drugs can be loaded into liposomes using passive loading techniques like mechanical dispersion or solvent dispersion methods.
Liposomes are spherical vesicles made of lipid bilayers that can encapsulate aqueous materials. They vary in size from 20nm to several microns. Liposomes can selectively deliver drugs to tissues and cells, increasing drug efficacy while reducing toxicity. They improve drug solubility, stability, and pharmacokinetics by encapsulating drugs in their aqueous core. Various preparation techniques including thin-film hydration, extrusion, and solvent injection are used to produce liposomes of defined size and lamellarity for drug delivery applications including cancer chemotherapy, gene delivery, and dermatology.
This document discusses liposomal drug delivery systems. It begins by defining liposomes as bilayered vesicles composed of phospholipids that can encapsulate aqueous cores. Liposomes range in size from 20nm to several micrometers. The document then outlines the advantages of liposomal drug delivery such as improved targeting, controlled release, and reduced toxicity. Several methods for preparing and loading liposomes are also described. The document concludes by discussing some applications of liposomal drug delivery including cancer therapy, antimicrobial treatments, and gene delivery.
This document provides an overview of liposomes, which are spherical vesicles composed of phospholipid bilayers that can encapsulate drugs for delivery. Key points include:
- Liposomes range in size from 25nm to 5000nm and consist of phospholipids, cholesterol, and an encapsulated drug molecule.
- They offer advantages for drug delivery such as ability to encapsulate both hydrophobic and hydrophilic drugs, increase drug stability, and provide controlled release.
- Common methods for preparing liposomes include lipid film hydration, mechanical dispersion techniques like sonication, and detergent removal methods.
- Liposomes have applications in cancer chemotherapy, oral drug delivery, topical applications, pulmonary delivery, and gene delivery due
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate drugs for delivery. They range in size from 25nm to 5000nm. Liposomes are prepared through methods like lipid film hydration, microemulsification, sonication, or membrane extrusion. They offer advantages for delivering both hydrophobic and hydrophilic drugs and allow for controlled release. Liposomes can be classified based on their structure, preparation method, composition, and application.
1. Liposomes are spherical vesicles made of concentric phospholipid bilayers that can encapsulate aqueous solutions. They form spontaneously when phospholipids are exposed to aqueous solutions.
2. Liposomes have many advantages for drug delivery such as increased drug efficacy, stability, and targeting to tumor tissues while reducing toxicity. However, they also have disadvantages like high production costs, drug leakage, and short half-life.
3. There are various methods for preparing and loading drugs into liposomes, including mechanical dispersion techniques using sonication or extrusion to reduce liposome size, and solvent dispersion techniques using thin film hydration. Characterization and stability testing of the liposomes is important.
This document provides an overview of liposome preparation and evaluation. It begins by defining liposomes as spherical sacs of phospholipid molecules that enclose an aqueous solution. The document then covers the structure of phospholipids and liposomes, various advantages and disadvantages, different classifications based on structure and preparation method, and common preparation techniques. Evaluation methods for liposomes are also discussed, along with their therapeutic applications and some examples of marketed liposomal products.
This document discusses liposomes, which are spherical vesicles made of phospholipids that can encapsulate drugs. It covers the mechanism of liposome formation, types of phospholipids used, methods of preparation, characterization, and applications. Liposomes can be used to deliver drugs to target sites and prolong drug circulation time, reducing side effects. They show potential for targeted delivery of anticancer drugs, vaccines, and other therapeutics.
This document provides an overview of liposomes as a drug delivery system. It begins by defining liposomes as spherical vesicles composed of lipid bilayers that can encapsulate aqueous volumes. Liposomes were first produced in 1961. The document then discusses the composition of liposomes, including phospholipids and cholesterol as main components. It describes various methods for liposome preparation, such as film hydration, sonication, extrusion, and detergent removal. Characterization techniques are also outlined. In summary, this document introduces liposomes as lipid bilayer structures for drug delivery and encapsulation, and covers their composition, methods of preparation, and characterization.
This document discusses liposomes, which are spherical vesicles made of lipid bilayers that can encapsulate drugs for targeted drug delivery. Liposomes have a microscopic spherical structure and are made of one or more concentric lipid bilayers composed of natural or synthetic phospholipids. They can encapsulate both hydrophilic and hydrophobic drugs within their aqueous interior or lipid bilayer. The main components of liposomes are phospholipids and cholesterol. Phosphatidylcholine is a commonly used phospholipid that has a hydrophilic head and hydrophobic tails. Cholesterol is also incorporated and affects the fluidity and permeability of the membrane. Liposomes are classified based on structure, method of preparation, composition, and provide advantages like targeted drug delivery and
Liposomes-Classification, methods of preparation and application Vijay Hemmadi
liposome preparation and application
A liposome is a tiny bubble (vesicle), made out of the same material as a cell membrane. Liposomes can be filled with drugs, and used to deliver drugs for cancer and other diseases. Membranes are usually made of phospholipids, which are molecules that have a head group and a tail group
Liposomes are spherical vesicles composed of lipid bilayers that can encapsulate aqueous content. They are used as drug delivery systems to improve drug solubility, stability, and targeting. Liposomes are prepared using various methods involving dispersion of lipids in aqueous solution. Key components are phospholipids like phosphatidylcholine and cholesterol. Characterization evaluates parameters like size, shape, drug entrapment efficiency, and phase behavior. Liposomes offer benefits like increased drug efficacy and stability but also have challenges like short shelf life and high production costs.
Liposomal drug delivery systems an overviewsana916816
1. Liposomes are spherical vesicles made of phospholipid bilayers that encapsulate aqueous volume. They were first produced in 1961 and can be used to deliver drugs.
2. Liposomes are composed mainly of phospholipids like phosphatidylcholine and cholesterol. Other components include phospholipid head groups, acyl chains, and a glycerol bridge.
3. Liposomes can be formed through various techniques including film hydration, extrusion, sonication, solvent injection, and freeze drying. These methods aim to produce unilamellar or multilamellar liposomes of defined size for drug delivery applications.
This document provides information on liposomes and nanoparticles for drug delivery. It defines liposomes as lipid bilayer structures composed of phospholipids that can encapsulate drug payload. Various preparation methods are described, including film hydration, solvent injection, and detergent removal. Key aspects of liposome characterization like size, drug encapsulation efficiency, and stability are covered. Applications include cancer therapy, gene delivery, and topical products. Common liposomal drugs are doxorubicin and amphotericin B. Nanoparticles are defined as submicron polymer structures that can be spheres or capsules. Preparation techniques include emulsion polymerization, solvent evaporation, and salting out. Nanoparticles offer advantages like versatile drug loading but
Liposomes are spherical vesicles made of phospholipid bilayers that can encapsulate hydrophilic or hydrophobic drugs. They were discovered in the 1960s and resemble natural cell membranes. Liposomes offer several advantages for drug delivery such as biocompatibility and the ability to target drugs. They can be classified based on size, number of bilayers, and preparation method. Key aspects of liposomes include their composition, surface charge, size, encapsulation efficiency, and ability to modify their properties for specific applications like cancer therapy, gene delivery, and transdermal drug administration.
Niosomes are vesicles composed mainly of hydrated non-ionic surfactant with or without cholesterol used for targetted drug delivery. Niosomes are better than liposomes as they are cost effective, stable, and can be stored for a long period of time.
liposomes used in preparation of both hydrophilic and hudrophobic drug.
it increases therapeutic efficiency by site targeting and increase circulatory time.
Liposomes are spherical vesicles composed of phospholipid bilayers that can encapsulate water-soluble drugs in their aqueous core and lipid-soluble drugs within their membrane. They have advantages for drug delivery such as providing selective targeting to tissues, increasing drug efficacy and stability, and reducing toxicity. However, they also have challenges with drug leakage and uptake by the reticuloendothelial system. Liposomes can be classified based on their lamellarity and size, and are prepared using methods like film hydration, ethanol injection, and detergent removal. They have applications for delivery of drugs, genes, vaccines, and contrast agents for imaging.
LPHNPs presentation is an illustration about the hybrid liposomes , types , methods and application , that gives a good idea about nanoparticles technology , the information has been collected from different references .
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
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Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
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A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
2. • Introduction
• Structure of liposomes
• Advantages& disadvantages
• Components of liposome
• Mechanism of liposome
• Preparation methods of liposomes
• Characterization of liposomes
• Applications of liposomes
• Summary
• Niosomes Introduction
• Advantages& disadvantages
• Preparation methods of niosomes
• Characterisation of niosomes
• summary
• References
3. LIPOSOMES
liposomes are concentric bilayered vesicles in which an aqueous
volume is entirely enclosed by a membraneous lipid bilayer
mainly composed of natural or synthetic phospholipids.
Liposomes were first produced in England in 1961 by
Alec D. Bangham. The size of a liposome ranges from some
20 nm up to several micrometers
1
4. Liposome =Phospholipid+
cholesterol
Hydrophillic head
Hydrophobic tail
The lipid moecules are usually phospholipids-amphipathic
moieties with a hydrophilic head group and two hydrophobic tails.
2
5. Advantages of
liposomes:
Provides selective passive targeting to tumor tissues.
(liposomal doxorubicin) .
Increased efficacy and therapeutic index.
Reduction in toxicity of the encapsulated agent.
Site avoidance effect (avoids non-target tissues).
Improved pharmacokinetic effects .
Flexibility to couple with site-specific ligands to achieve
active targeting.
3
6. Disadvantages of liposomes:
Production cost is high.
Leakage and fusion of encapsulated drug /
molecules.
Sometimes phospholipid undergoes oxidation
and hydrolysis like reaction.
Short half-life.
Low solubility.
4
10. Phospholipids
Phosphatidylcholine- natural
Amphipathic molecule
Hydrophilic polar head-
Phosphoric acid bound to water
soluble molecule.
Glyceryl bridge
Hydrophobic tail-
2 fatty acid chain containing 10-24 carbon
atoms and 0-6 double bond in each chain.
The amphipathic molecule self organise
in ordered supramolecular structure when
confronted (meet face to face)
with solvent.
8
11. The most common natural phospholipid is the
phospatidylcholine (PC ).
Polar Head Groups
Naturally occurring phospholipids used are :
PC: Phosphatidylcholine.
PE: Phosphatidylethanolamine.
Three carbon glycerol
PS: Phosphatidylserine
Synthetic phospholipids used are:
DOPC: Dioleoyl phosphatidylcholine
DSPC: Disteroyl phosphatidylcholine
DOPE: Dioleoyl phosphatidylethanolamine
DSPE: Distearoyl phosphatidylethanolamine
9
13. Molecules of PC are not soluble in water.
In aqueous media they align themselves closely in planar bilayer sheets
in order to minimize the unfavorable action between the bulk aqueous
phase and the long hydrocarbon fatty chain.
Such unfavorable interactions are completely eliminated when the
sheets fold on themselves to form closed sealed vesicles
11
14. PHASE TRANSITION
TEMPERATURE phospholipid membranes can exist
At various temperatures,
in different phases.
The transition from one phase to another can be detected by
technique like micro calorimetry .
What exactly happens during phase transition?
Tightly ordered At elevated temperature liquid crystal phase
gel state
( lipid membrane) (movement is higher)
This is due to the fatty acid chain adopting a new
conformation other than all trans straight chain configuration,
such as gauche configuration state( phenomenon- chain
tilt )
12
15. B. Cholesterol:
Cholesterol stabilizes the Membrane
Steroid lipid
Interdigitates between phospholipids.
i.e. below Tc , it makes membrane less ordered & above Tc more ordered.
Being an amphipathic molecule, cholesterol inserts into the
membrane with its hydroxyl group of cholesterol oriented
towards the aqueous surface and aliphatic chain aligned parallel to
the acyl chains in the center of the bilayer . 13
16. Role of cholesterol in bilayer
formation:
Cholesterol act as fluidity buffer
After intercalation with phospholipid molecules alter the
freedom of motion of carbon molecules in the acyl
Chain
Restricts the transformations of trans to gauche
Conformations.
Incorporated into phospholipid membrane upto 1:1 or
2:1 of cholesterol to PC.
14
18. Classification of liposome :
Classification
of liposome
Structural Method of Composition
parameters preparation and application
16
19. Lamella :
Types of vesicles based on lamella
17
20. A. Structural
parameters:
Based on structural
parameters
MLV OLV UV MVV
Multilamellar oligolamellar Multivesicular
Unilamellar
Large vesicles vesicles vesicles
(>0.5 um) (>0.1-1.0 um) Vesicles (> 1.0 UM)
SUV
MUV 20-100nm
GUV LUV
>1um >100nm 18
21. B. Based on REV, SUV made
method of by reverse
phase
preparation: evaporation
method
VET
SPLV
Vesicles Based on
method of Stable
prepared by
preparation plurilamenar
extrusion
vesicles
tech.
FATMLV
Frozen &
thawed MLV 19
22. Based on
composition
and convential
application:
immuno fusogenic
Based on
composition
& application
Long pH
circulatory sensitive
cationic
20
23. MethodS of Liposome Preparation
Passive
Loading of the entrapped agents
loading before/ during the manufacture
technique procedure.
Active/remo Certain types of compounds with
ionizable groups & those with both
te loading lipid & water solubility can be
technique Introduced into liposomes after the
formation of intact vesicles.
21
24. Methods of liposome preparation
Passive loading techniques Active loading techniques
Mechanical dispersion Solvent dispersion Detergent removal
methods methods technique
LIPID FILM HYDRATION ETHANOL INJECTION DETERGENT REMOVAL
BY HAND SHAKING,FREEZE
DRYING OR NON HAND ETHER INJECTION FORM MIXED MICELLES
SHAKING
DOUBLE EMULSION BY DIALYSIS
MICRO EMULSIFICATION
REVERSE PHASE CHROMATIGRALPY
SONICATION
VAPOURATION VESICLES DIFFUSION
FRENCH PRESSURE CELL
STABLE PLURI LAMELLER VESICLES LIKE….
MEMBRANE EXTRUSON 22
VESICLES RECONSTITUTED &
DRIED RECONSTITUTED
VESICLES SANDAI VIRUS ENVELOPE
26. 1. Mechanical dispersion method:
Lipid dissolve in organic solvent/co-solvent
Remove organic solvent under vacuum
Film deposition
Solid lipid mixture is hydrated by using aqueous buffer
Lipid spontaneously swell & Hydrate
Liposome
Post Hydration vortexing, sonication, freeze thawing &
high pressure extrusion 24
27. There are four basic methods of physical/mechanical
dispersion :
Hand shaken method.
Non shaking method.
Pro – liposomes .
Freeze drying .
25
28. Lipidsform stacks of film
from organic solution
(FE/HS)
Then film is treated with
aqueous medium
Upon hydration lipids
swell and peel out from
RB flask
vesiculate to form Multi
lamellar vesicles(MLVs)
26
29. Pro-liposomes:
To increase the surface area of dried lipid film & to
facilitate instantaneous hydration.
lipid Dried
over
Finely divided
lipid particulate support Pro - liposomes
like powdered NACL/
sorbital
Pro- Dispersion of MLV’S
water
liposomes
This Method overcome the stability problem. 27
30. Processing of the lipids hydrated by physical means or the
mechanical treatments of MLVs :
Micro Emulsification liposomes (MEL)
Sonicated unilamellar vesicles (SUVs)
French Pressure Cell Liposomes .
Membrane extrusion Liposomes
Dried reconstituted vesicles(DRVs)
Freeze thaw sonification (FTS)
pH induced vesiculation
Cochleate method. 28
31. Sonicated unilamellar vesicles:
The exposure of MLVs to ultrasonic
irradation for producing small vesicles.
Probe sonicator Bath sonicator
Used for dispersions large volume
require high of dilute lipids
energy in
small volumes
Sonication
MLVs hazy transparent
5-10 min solution
centrifugation 30 min
clear SUV 29
Dispersion.
33. French pressure cell liposomes:
Extrusion of preformed large liposomes in french press under very
high pressure .
uni or oligo lamellar liposomes of intermediate size (30-80nm ) .
Advantages
Less leakage and more stable liposomes are formed compared to
sonicated forms
31
34. Vesicles prepared by extrusion technique :
The size of liposomes is
reduced by gently passing them
through polycarbonate
membrane filter of defined
pore size at lower pressure
Used for preparation of LUVs
and MLVs
32
36. pH induced vesiculation:
The transient change in pH brings about
an increase in surface charge of the lipid
bilayer which induces spontaneous LUVs
vesiculation .
Reduced the pH
to 7.5
Exposed to high pH * Addition of
~ (addition of 1M 0.1M Hcl
Preformed NaoH)
MLV’S
~Period of
(2.5-3.0)
exposure < 2min
MLVs 34
37. Cochleate method:
Cochleates
Removal
of Ca++ by
Cylindrical EDTA
rolls(cochleate
Addition of cylinders)
Ca++ ions
SUVs made
from
phosphatidylse
rine(PS)
35
38. Solvent dispersion methods:
Lipid dissolve in organic solvent
Excess addition of aqueous phase
Lipids allign at interface of aqueous and organic layer
Formation of monolayer and bilayer of phospholipids
Liposome
Note:- Organic solvent miscible with aqueous phase
36
40. De-Emulsification method:
Generally the liposome is made up in 2 steps: Aqueous medium
containing material
1 st the inner leaflet of the bilayer . to be entrapped
Then the outer half.
Add to immiscible
organic solution of
lipid
Mechanical agitation
Microscopic water
droplets
Methods to prepare the droplets:
~Double emulsion vesicles
~Reverse phase evaporation vesicles 38
~Sonication methods
42. DETERGENT SOLUBILISATIOIN METHODS
Phospholipid brought into intimate contact with
aqueous phase
By addition optimized concentration of detergent
Formation of micelles (Liposome)
Below CMC, detergent molecules exist in free soln. As the
concentration is increased, micelles are formed.
Note:- Liposome size and
Methods to remove detergents:
shape depend on chemical
Dialysis
nature of
Column chromatography.
detergent, concentration and 40
other lipid involved
43. Active/remote loading technique:
The lipid bilayer membrane is impermeable to ions & hydrophilic
molecules. But, Permeation of hydrophobic molecules can be controlled
by concentration gradients.
Some weak acids or bases can be transported due to various
transmembrane gradients
Electrical gradients.
Ionic(pH) gradients.
Chemical potential gradients.
Weak amphipathic bases accumulate in aq phase of lipid vesicles
in response to difference in pH b/w Inside & outside of
liposomes 41
44. Solute bearing no Liposomes with low
internal pH
charge at neutral pH pH gradient is created by preparing liposomes
with low internal pH.
Addtn of base to extraliposomal medium.
[Basic compds ( lipophilic (non ionic) at high
pH & hydrophilic(ionic) at low pH)]
Neutral solute passes Lipophilic (UNPROTONATED) drug diffuse
easily through bilayer through the bilayer
membrane by
diffusion
At low pH side, the molecules are
predominantly protonated .
Exchange of external medium by gel extrusion
chromatorapghy with neutral solution.
Charge aquired by
solute inside Weak bases like doxorubicine,
liposomes makes adriamycin and vincristine are
them unable to exit encapsulated. 42
45. Locus of drugs in liposomes:
Hydrophilic (DOXORUBICIN)
Low entrapment
Leakage
Hydrolytic degradation
Lipophilic (CYCLOSPORINE)
High entrapment
Low leakage
Chemical stability
Ampiphilic (VINBLASTIN)
High entrapment
Rapid leakage
Biphasic insoluble
(ALLOPURINOL, 6-
MERCAPTOPURINE)
Poor loading & entrapment 43
51. Encapsulation of drugs in liposomes:
• Encapsulation volume/Trapped volume
Volume of aqueous solution entrapped in liposomes per mole of PL (µL/µmol PL)
• Encapsulation Efficiency
Assessed by mini column centrifugation method & protamine aggregation method.
protamine aggregation method used for neutral and negetively charged liposomes.
Liposome dispersion can be precipitated with protamine solution and subsequent
centrifugation at 2000RPM.
By analysing the material in super natent & in liposome pellet ( after disrupting
liposomal pellet with 0.6 ml of 10% triton x-100 ). The encapsulation efficiency of
entrapped material can be estimated.
• % Encapsulation
Drug entrapped in liposomes
x 100
Total drug added
49
52. In gene delivery.
As drug delivery carriers.
Enzyme replacement therapy.
Chelation therapy for treatment of heavy metal poisoning.
Liposomes in antiviral/anti microbial therapy.
In multi drug resistance.
In tumour therapy.
In immunology.
In cosmetology
50
53. DNA delivery of Genes by Liposomes
Cheaper than viruses
No immune response
Especially good
for in-lung delivery (cystic fibrosis)
100-1000 times more plasmid DNA needed
for the same transfer efficiency as for viral vector 51
55. Liposomes could serve as tumor specific vehicles
(even without special targeting)
Liposomes better penetrate into tissues
with disrupted endothelial lining 53
57. NAME TRADE NAME COMPANY INDICATION
Liposomal Abelcet Enzon Fungal infections
amphotericin B
Liposomal Ambisome Gilead Sciences Fungal and protozoal infections
amphotericin B
Liposomal cytarabine Depocyt Pacira (formerly Malignant lymphomatous meningitis
SkyePharma)
Liposomal DaunoXome Gilead Sciences HIV-related Kaposi’s sarcoma
daunorubicin
Liposomal doxorubicin Myocet Zeneus Combination therapy with cyclophosphamide in
metastatic breast cancer
Liposomal IRIV vaccine Epaxal Berna Biotech Hepatitis A
Liposomal IRIV vaccine Inflexal V Berna Biotech Influenza
Liposomal morphine DepoDur SkyePharma, Endo Postsurgical analgesia
Liposomal verteporfin Visudyne QLT, Novartis Age-related macular degeneration, pathologic
myopia, ocular
histoplasmosis
Liposome-PEG Doxil/Caelyx Ortho Biotech, HIV-related Kaposi’s sarcoma, metastatic breast
doxorubicin Schering-Plough cancer, metastatic
ovarian cancer
55
Micellular estradiol Estrasorb Novavax Menopausal therapy
58. summary:
o liposomes are concentric bilayered vesicles in which an aqueous
volume is entirely enclosed by a membraneous lipid bilayer
o Liposomes are one of the unique drug delivery system, in controlling
and targeting drug delivery.
o Components of liposomes include phospholipid and cholesterol.
o Method of preparation of liposomes include active loading technique
and passive loading technique.
o Passive loading techniques include solvent mechanical dispersion,
solvent dispersion & detergent solubilisation
o Characterization of liposomes include physical,chemical and
56
biological.
60. Niosomes are non-ionic surfactant based unilamellar or multilamellar
bilayer vesicles up on hydration of non ionic surfactants with or
without incorporation cholesterol .
The niosomes are very small, and microscopic in size. Their size lies
in the nanometric scale.
Niosomes are a novel drug delivery system, in which the medication is
encapsulated in a vesicle. Both hydrophilic
& lipophilic drugs ,entrap either in the
aqueous layer or in vesicular membrane
made of lipid materials.
57
61. Hydrophilic drugs Polar heads facing
Structure of niosomes: located in hydrophilic region
aqueous regions
Head part encapsulated
(hydrophillic)
Tail part
(hydrophobic)
Drug molecules
Hydrophobic drugs
localized in the
Phospholipids hydrophobic
lamellae
These vesicular systems are similar to liposomes that can be
used as carriers of amphiphilic and lipophilic drugs.
It is less toxic and improves the therapeutic index of drug by
restricting its action to target cells. 58
62. Advantages of niosomes:
They are osmotically active and stable.
They increase the stability of the entrapped drug.
The vesicle suspension being water based offers greater patient
compliance over oil based systems
Since the structure of the niosome offers place to accommodate
hydrophilic, lipophilic as well as ampiphilic drug moieties, they can be
used for a variety of drugs.
The vesicles can act as a depot to release the drug slowly and of
controlled release.
Biodegradable, non-immunogenic and biocompatible. 59
64. Classification of niosomes
Small Large
Unilamellar Unilamellar Multilamellar
Vesicle Vesicle Vesicle
(SUV) (LUV) (MLV)
Typical Size Ranges: SLV: 20-50 nm – MLV:100-1000 nm
61
65. Components of niosomes:
Cholesterol and Non ionic surfactants are the two major components
used for the preparation of niosomes.
Cholesterol provides rigidity and proper shape. The surfactants play a
major role in the formation of niosomes.
non-ionic surfactants like spans(span 20,40,60,85,80), tweens (tween
20,40,60,80) are generally used for the preparation of
Niosomes.
Few other surfactants that are reported to form niosomes are as follows :
Ether linked surfactant
Di-alkyl chain surfactant
Ester linked
Sorbitan Esters
Poly-sorbates
62
66. alkyl group chain
length : C12-C18
Shud be above Span surfactants
the gel to liquid with HLB values
phase transition 4 and 8
temperature of Hydration Non-ionic
the system Temperature surfactant
nature
Factors
affecting
Surfactants niosomes
and lipid Membrane
formation additives
levels
surfactant/lipid
ratio: 10-30 mM Nature of Cholesterol: Prevent
encapsulated vesicle aggregation.
drug Dicetyl phosphate: -ve
charge
63
67. Concept of Critical Packing Parameter
Prediction of vesicle forming ability is not a simply a matter of HLB
CPP = v/lca0
where
v - hydrophobic group volume,
lc - critical hydrophobic group length and
a0 - area of the hydrophilic head group
CPP between 0.5 and 1 likely to form vesicles.
< 0.5 (indicating a large contribution from the hydrophilic head group
area) is said to give spherical micelles.
>1 (indicating a large contribution from the hydrophobic group volume)
should produce inverted micelles.
64
68. Comparisition between liposomes &
niosomes:
Sl. Liposomes Niosomes
No.
1. Vesicles made up of concentric Vesicles made up of surfactants
bilayer of phospholipids with or without incorporation of
cholesterol.
2. Size ranges from 10-3000nm Size ranges from 10-100nm
3. Comparatively expensive Inexpensive
4. Special storage condition are No such special requirement
required
5. Phospholipids used are unstable Non-ionic surfactants are stable
6. Comparatively more toxic Less toxic
65
71. Reverse phase evaporation technique :
Surfactant is dissolved in chloroform ond 0.25 volume of PBS buffer is
emulsified to get a W/O emulsion.
sonicated
chloroform is evaporated under reduced pressure.
The lipid or surfactant forms a gel first and hydrates to form vesicles.
Free drug (unentrapped) is generally removed by dialysis.
sonication:
Surfactant +cholesterol Mixture is sonicated for 3
mixture is dispersed in 2 ml min at 60 C using titanium
aqueous phase in vial probe sonicator
Unilamellar niosomes 68
73. Multiple membrane extrusion Method:
•Mixture of surfactant, cholesterol and
dicetyl phosphate in chloroform is made
into thin film by evaporation
•The film is hydrated with aqueous drug
solution and the resultant suspension
extruded through polycarbonate membranes
70
74. Bubble method:
RBF as bubbling unit with three necks in water
It is novel technique for the bath.
one step preparation of
liposomes and niosomes Reflux , thermometer and nitrogen supply by
three necks
without the use of organic
solvents. Cholesterol+ Surfactant dispersed in buffer
pH 7.4 at 70°C
Above dispersion is homogenized for 15 sec and
then bubbled with nitrogen gas at 70°C to get
niosomes
71
75. proniosomes:
• Bubble Method
• Formation of niosomes from proniosomes:
It is prepared by coating water-soluble carrier such as sorbitol with
surfactant. The result of the coating process is a dry formulation. In
which each water-soluble particle is covered with a thin film of dry
surfactant. This preparation is termed “Proniosomes”.
72
76. Separation of unentrapped drug:
Gel filtration Separation of
unentrapped Centrifugation
drug The niosomal suspension
The unentrapped drug is
is centrifuged and the
removed by gel filtration of
supernatant is separated.
niosomal dispersion through a
The pellet is washed and
Sephadex-G-50 column and
then resuspended to obtain
elution with phosphate
a niosomal suspension free
buffered saline Dialysis from unentrapped drug.
Dialyzed in a dialysis tubing
against phosphate buffer or
normal saline
Gel Filtration Centrifuser 73
77. a) Size, Shape and Morphology
Freeze Fracture Electron Microscopy:- Visualize the vesicular structure of
surfactant based vesicles.
Photon Correlation spectroscopy :- Determine mean diameter of the
vesicles.
Electron Microscopy :- Morphological studies of vesicles.
b) Entrapment efficiency
After preparing niosomal dispersion, unentrapped drug is separated by
dialysis and the drug remained entrapped in niosomes is determined by
complete vesicle disruption using 50% n-propanol or 0.1% Triton X-100
and analysing the resultant solution by appropriate assay method for the
drug.
c) Vesicle Suface Charge
Determined by measurement of electrophoretic mobility and expressed in
expressed in terms of zeta potential
d) In vitro studies 74
79. Lancôme has come out with a variety of anti-ageing
products which are based on noisome formulations.
L‟Oreal is also conducting research on anti-ageing
cosmetic products.
76
80. Summary :
Niosomes provide incorporating the drug into for a
better targeting of the drug at appropriate tissue
destination .
They presents a structure similar to liposome and hence
they can represent alternative vesicular systems with
respect to liposomes
Niosomes are thoughts to be better candidates drug
delivery as compared to liposomes due to various factors
like cost, stability etc. Various type of drug deliveries can
be possible using niosomes like targeting, ophthalmic,
topical, parenteral etc.
77
81. 1. S.P. Vyas And R.K. Khar,targeted & Controlled Drug
Delivery,liposomes,173-279.
2. Mohammad Riaz, Liposomes :Preparation Methods,
Pakistan Journal Of Pharmaceutical Sciences, January
1996,Vol.19(1),65-77.
3. Sharma Vijay K1*, Liposomes: Present Prospective and
Future Challenges,International Journal Of Current
Pharmaceutical Review And Research, oct 2010,vol1,
issue 2,6-16
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82. 5. Madhav Nvs* And Saini A, Niosomes: A Novel
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7. Pawar Sd *, Pawar Rg, Niosome: An Unique Drug
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83. Success in life mostly depends on the power of
„CONCENTRATION‟
--- Swami Vivekananda
Editor's Notes
Vesicle contents are exchanged with the dispersion medium during breaking and resealing of phospholipid bi layers as they pass into membrane
polysorbate 20 ,should be above the gel to liquid phasetransition temperature of system.leads to gel to liq transition in niosomes,
Niosomes for the treatment of Leishmaniasis-Niosomes are being used for the delivery of stilbogluconate an antileishmaniasis agent for its delivery to visceral organs. It may be related to passive delivery of the vesicles and the contents through RES recognition and uptake by the Kupffer cells. Niosomes in Oncology:- Various anticancer drugs like MTX, DOX, can be encapsulated inside the niosomes and bac easily be delivered to the tumor cells due to small size. Niosomes as immunological adjuvants:- The ability of niosomes to enhance antibody production in response to Bovine Seum Albumin was compared with Freud’s adjuvant in the Balb/c mice which revealed niosomes as potent stimulator of cellular immunity. 4. Niosomes and Oral drug delivery:-Niosomes can be used for oral delivery of drug thus protecting it from the hostile environment of the GIT and targeting to RE.5. Niosomes for Transdermal drug delivery:- They are being used in topical and transdermal products both contaning hydrophobic and hydrophillic drugs. The intracellular route is the main route of vesicle penetration across the skin.6. Niosomes in Diagnostic imaging:-Niosomes can act as carriers for radiopharmaceuticals and site specific vehicle for spleen and liver imaging.
Niosomes for the treatment of Leishmaniasis-Niosomes are being used for the delivery of stilbogluconate an antileishmaniasis agent for its delivery to visceral organs. It may be related to passive delivery of the vesicles and the contents through RES recognition and uptake by the Kupffer cells. Niosomes in Oncology:- Various anticancer drugs like MTX, DOX, can be encapsulated inside the niosomes and bac easily be delivered to the tumor cells due to small size. Niosomes as immunological adjuvants:- The ability of niosomes to enhance antibody production in response to Bovine Seum Albumin was compared with Freud’s adjuvant in the Balb/c mice which revealed niosomes as potent stimulator of cellular immunity. 4. Niosomes and Oral drug delivery:-Niosomes can be used for oral delivery of drug thus protecting it from the hostile environment of the GIT and targeting to RE.5. Niosomes for Transdermal drug delivery:- They are being used in topical and transdermal products both contaning hydrophobic and hydrophillic drugs. The intracellular route is the main route of vesicle penetration across the skin.6. Niosomes in Diagnostic imaging:-Niosomes can act as carriers for radiopharmaceuticals and site specific vehicle for spleen and liver imaging.
Niosomes for the treatment of Leishmaniasis-Niosomes are being used for the delivery of stilbogluconate an antileishmaniasis agent for its delivery to visceral organs. It may be related to passive delivery of the vesicles and the contents through RES recognition and uptake by the Kupffer cells. Niosomes in Oncology:- Various anticancer drugs like MTX, DOX, can be encapsulated inside the niosomes and bac easily be delivered to the tumor cells due to small size. Niosomes as immunological adjuvants:- The ability of niosomes to enhance antibody production in response to Bovine Seum Albumin was compared with Freud’s adjuvant in the Balb/c mice which revealed niosomes as potent stimulator of cellular immunity. 4. Niosomes and Oral drug delivery:-Niosomes can be used for oral delivery of drug thus protecting it from the hostile environment of the GIT and targeting to RE.5. Niosomes for Transdermal drug delivery:- They are being used in topical and transdermal products both contaning hydrophobic and hydrophillic drugs. The intracellular route is the main route of vesicle penetration across the skin.6. Niosomes in Diagnostic imaging:-Niosomes can act as carriers for radiopharmaceuticals and site specific vehicle for spleen and liver imaging.