Liposomes

Liposomes : Modified Drug Delivery System

1. LIPOSOMES h 1 Presented by: Aditya Singh PhD (Pharmaceutics) 2001014 Applied Pharmaceutics

2. CONTENT Introduction Advantages Disadvantages Extraction Method Formulation of Liposome Liposomal examination In vitro drug release study Storage Stability study of liposomes Scanning Electron Microscopy (SEM) pH 2

3. Structure of liposomes 3 Fig 1. Liposome

4. INTRODUCTION Liposomes were first described by British hematologist Alec D Bangham in 1961 (published 1964). Liposomes are small artificial vesicles of spherical shape and composed of one more phospholipids bilayer and an aqueous core at the centre and have amphipathic in nature. Liposomes, were consists of Lipos (fat) + soma (body). Liposomes composed of lecithin which are used as encapsulator antioxidant and cholesterol is an important component of biological membrane. 4

5. ADVANTAGE OF LIPOSOMES Liposomes increased efficacy and therapeutic index of drug. Liposome increased stability via encapsulation. Liposomes are non-toxic, flexible, biocompatible, completely biodegradable, and non-immunogenic for systemic and non-systemic administrations. Liposomes reduce the toxicity of the encapsulated agent. Liposomes help to reduce the exposure of sensitive tissues to toxic drugs site avoidance effect. Flexibility to couple with site-specific to achieve active targeting. 5

6. Disadvantages of liposome Low solubility. Short half-life. Leakage and fusion of encapsulated. drug/molecules. Production cost is high. 6

7. Classification of Liposmes 7 Fig 2. Types of liposomes formation

8. Formulation of Liposome by Rotatory Vacuum Evaporator method 8 Fig 3. Liposome preparation

9. Microscopic image of liposome 9 Fig 4. Microscopic examine of liposomes formation

10. Evaluation Parameters pH Spreadability studies Viscosity Drug entrapment studies SEM 10

11. V iscosity 11 Rheological analysis of the experimental liposome was performed by using Rheometer . Fig 5 . Types of liposomes formation

12. In vitro drug release study 12 The release studies were carried out in 250 ml beaker containing 100 ml of phosphate buffer pH 6.8. The beaker was assembled on a magnetic stirrer and the medium was equilibrated at 37±50C. Dialysis membrane was taken and one end of the membrane was sealed. Fig 6 . In vitro release of liposomes

13. Drug entrapment efficiency of liposomes Entrapment efficiency of liposomes was determined by centrifugation method, the liposomes were subjected to centrifugal on a laboratory centrifuge ( Remi R4C) at 3500 rpm at 5ºC for a period of 45 min to separate the free drug from solution. 13

14. Scanning Electron Microscopy (SEM ) Emission Scanning Electron Microscope (SEM) provides the surface morphology of the sample. 14

15. pH of the Liposomes The pH of liposomes formulations was determined by using digital pH meter. About 1g of the liposomes was weighed and dissolved in 100 ml of distilled water and stored for 1 hours. 15 Fig 7 . pH parameter for liposome testing

16. Application of Liposomes Site specific targeting. Sustained / controlled release. Gene therapy. Herbal preparation. Anti-Aging. Ocular delivery of antibiotic . 16

17. List of Marketed Formulation 17

18. REFERENCES Bangham A, Standish M.M, Watkins J, 1965, Diffusion of univalent ions across the lamellae of swollen phospholipids, Journal of Molecular Biology , Vol. 13, pp. 238-252. Torchilin , V, Weissig , V, 2003, Liposomes: A Practical Approach. Oxford University Press: Kettering , UK, Vol.4, pp.77-101. Vemuri S, Rhodes CT, 1995, Preparation and characterization of liposomes a therapeutic delivery system, a review, Pharmaceutica Acta Helvetiae , 70(2), 95-111. Khan I, Elhissi A, Shah M, Alhnan MA, Waqar A, 2013, Liposome based carrier systems and devices used for pulmonary drug delivery, In: DAVIM JP (ed.) Biomaterial and medical tribology research and development, pp. 395-443. Khan I, Yousaf S, Subramanian S, Alhnan M A, Ahmed W, 2007, Proliposome Powders for the Generation of Leptosomes, the Influence of Carbohydrate Carrier and Separation Conditions on Crystallinity and Entrapment of a Model Antiasthma Steroid, AAPS Pharm SciTech , pp.1-13. 18

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