Liposome an Advantage in Drug Delivery
Liposomes Definition and background10
Liposomes were discovered in the early 1960’s and subsequently studied as cell membrane models. They have since gained recognition in the field of drug delivery. Liposomes are spherical vesicles which can be thought of as a hollow sphere they are composed of a bilayer membrane which entraps an aqueous core. The particle size of liposomes ranges from 20 nm to 10 μm in diameter.
Liposomes vary in charge and in size depending on their manufacturing protocol and type of (phospho) lipid bilayer used (the small unilamellar vesicle (SUV) size range is 0.02 -0.05 μm, the large unilamellar vesicles (LUV) size range is greater than 0.06 μm and the multilamellar vesicle (MLV) size range is 0.1 – 0.5 µm).
The physicochemical characteristics of the liposomes, like particle size, lamellarity, surface charge, sensitivity of pH changes and bilayer rigidity can be modified. Liposomes showed promising result in the drug delivery but their applicability is limited primarily to specific use because of short half-life in blood circulation.
The circulation time of liposomes in the blood stream is dramatically increased by attaching polyethylene glycol (PEG) – units to the bilayer, known as long circulating (Stealth) liposomes.
Main advantages of liposomes are that they offers suitable means for delivering drugs combined with the potential of improving the therapeutic index while greatly reducing the side effects. Liposomes are potential carrier for controlled drug release of tumors therapeutic agents and antibiotic, for gene and antisense therapy through nucleic acid sequence delivery, immunization through antigen delivery and for antiparkinsons. Last one decade, pharmaceutical researcher’s use the tools of biophysics in evaluating liposomal dosage forms. Liposomes have covered predominantly medical, albeit some non-medical areas like bioreactors, catalysts, cosmetics and ecology.
The structure is known as a phospholipid bilayer of
Liposomes were discovered in the early 1960’s and subsequently studied as cell membrane models. They have since gained recognition in the field of drug delivery. Liposomes are spherical vesicles which can be thought of as a hollow sphere they are composed of a bilayer membrane which entraps an aqueous core. The particle size of liposomes ranges from 20 nm to 10 μm in diameter.
Liposomes vary in charge and in size depending on their manufacturing protocol and type of (phospho) lipid bilayer used (the small unilamellar vesicle (SUV) size range is 0.02 -0.05 μm, the large unilamellar vesicles (LUV) size range is greater than 0.06 μm and the multilamellar vesicle (MLV) size range is 0.1 – 0.5 µm).
The physicochemical characteristics of the liposomes, like particle size, lamellarity, surface charge, sensitivity of pH changes and bilayer rigidity can be modified. Liposomes showed promising result in the drug delivery but their applicability is limited primarily to specific use because of short half-life in blood circulation.
The circulation time of liposomes in the blood stream is dramatically increased by attaching polyethylene glycol (PEG) – units to the bilayer, known as long circulating (Stealth) liposomes.
Main advantages of liposomes are that they offers suitable means for delivering drugs combined with the potential of improving the therapeutic index while greatly reducing the side effects. Liposomes are potential carrier for controlled drug release of tumors therapeutic agents and antibiotic, for gene and antisense therapy through nucleic acid sequence delivery, immunization through antigen delivery and for antiparkinsons. Last one decade, pharmaceutical researcher’s use the tools of biophysics in evaluating liposomal dosage forms. Liposomes have covered predominantly medical, albeit some non-medical areas like bioreactors, catalysts, cosmetics and ecology.
The structure is known as a phospholipid bilayer of