LIPOSOMES INTRODUCTION AND TYPES.pptx

Liposomes is Greek words means ‘Lipo’ mean ‘Fat’ and ‘Somes’ mean ‘Body’.
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 extensively used as carriers for numerous molecules in cosmetic and pharmaceutical industries.

1. SEMINAR MOLECULAR PHARMACEUTICS LIPOSOMES- INTRODUCTION AND TYPES SUBMITTED BY, ARDRA KRISHNA P V MPHARM 2 ND SEMESTER DEPARTMENT OF PHARMACEUTICS KMCH COLLEGE OF PHARMACY 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 1

2. CONTENT 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 2

3. TARGETING METHODS Rational Research in drug delivery began in 1950s . Need for Targeted/controlled Drug Delivery : Delivery of the drug at a rate and/or a location dictated by the needs of the body or disease state over a specified period of time. 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 3

4. LIPOSOMES Liposomes is Greek words means ‘ Lipo ’ mean ‘ Fat ’ and ‘ Somes ’ mean ‘ Body ’. 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 extensively used as carriers for numerous molecules in cosmetic and pharmaceutical industries. 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 4

5. Discovered in 1960‟s by Bangham and coworkers . The size range of liposome: 20 nm up to several micrometers . Due to their size and hydrophobic and hydrophilic character(besides biocompatibility), liposomes are promising systems for drug delivery . The choice of bilayer components determines the ‘rigidity’ or ‘fluidity’ and the charge of the bilayer . 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 5

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8. COMPOSITION OF LIPOSOMES There are number of components of liposomes however Lecithin (mixture of phospholipids) and cholesterol being main components . 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 8

9. PHOSPHOLIPIDS Phospholipids are fatty substances the major structural components of cell wall & biological membranes. Phospholipids are amphipathic moieties with a hydrophilic head group and two hydrophobic tails. Two types of phospholipids exist – PHOSPHODIGLYCERIDES AND SPHINGOLIPIDS , together with their corresponding hydrolysis products. Phospholipids have phosphatidyl moiety (tail) with different head groups (choline, Ethanolamine, Serine) The most common phospholipid is P hosphatidylcholine (PC) molecule. 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 9

10. 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 10 Phosphatidylcholine has glycerol bridge links a pair of hydrophobic acyl hydrocarbon chains having 10-24 carbon atoms with a hydrophilic polar head group.

11. ADVANTAGES Provides selective passive targeting to tumor tissues (liposomal doxorubicin). Increased efficacy and therapeutic index. Increased stability via encapsulation. Reduction in toxicity of the encapsulated agent. Improved pharmacokinetic effects ( reduced elimination , increased circulation life times). Flexibility to couple with site-specific ligand to achieve active targeting. Site avoidance effect (avoids non- target tissues ). 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 11

12. DISADVANTAGES Very high production cost. Drug leakage/ entrapment/ drug fusion. Sterilization. Short biological activity / t ½. Oxidation of bilayer phospholipids. Repeated iv administration problems. 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 12

13. STERILIZATION OF LIPOSOMES D ue to the particular sensitivity of liposomes and their tendency to physicochemical alterations, their sterilization remains a real challenge. Conventional sterilization methods such as heat, ethylene oxide, ultraviolet and gamma irradiations are considered as unsuitable for liposome sterilization. The search for an alternative method being therefore necessary, the applicability of SUPERCRITICAL CARBON DIOXIDE (ScCO 2 ) TECHNOLOGY , which is nowadays a promising strategy for the sterilization of sensitive products such as liposomes. ScCO 2  could effectively be an interesting alternative to achieve sterility of liposomes . 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 13

14. TYPES 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 14 CLASSIFICATION LIPOSOMES CAN BE CLASSIFIED BASED ON THREE DIFFERENT CRITERIA :

15. CLASSIFICATION OF LIPOSOMES 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 15

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19. NOVEL LIPOSOMES 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 19

20. 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 20 TRANSFEROSOMES ARCHEOSOMES VIROSOMES ETHOSOMES

21. MARKETED FORMULATIONS CARRIER SYSTEM TARGETED SITE CARRIER FORMULATION MARKETED EXAMPLES IV TUMOR CELL LIPOSOMES POWDER , DISPERSION AND SOLVENT FOR CONCENTRATE FOR DISPERSION FOR INFUSION myocet IV FUNGAL CELL WALL LIPOSOMES POWDER FOR DISPERSION FOR INFUSION AmBisome® 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 21

22. LIPOSOMES AND CANCER Liposomes have revolutionized cancer therapy by their broad clinical applications. Liposomes overcome the limitations of conventional chemotherapy by improving the bioavailability and stability of the drug molecules and minimizing side effects by site-specific targeted delivery of the drugs. 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 22

23. Biological Challenges Facing Liposomal Drug Delivery Systems As with any foreign particle that enters the body, liposomes encounter multiple defense systems aimed at recognition, neutralization, and elimination of invading substances. These defenses include the RES ( Reticuloendothelial system), opsonization, and immunogenicity. While these obstacles must be circumvented for optimal liposome function, other factors such as the enhanced permeability and retention (EPR) effect can be exploited to enhance drug delivery. 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 23

24. REFERENCES Akbarzadeh , A., Rezaei-Sadabady , R., Davaran , S.  et al.  Liposome: classification, preparation, and applications.  Nanoscale Res Lett   8,  102 (2013). https:// doi.org/10.1186/1556-276X-8-102 Sriram Vemuri , C.T Rhodes, Preparation and characterization of liposomes as therapeutic delivery systems: a review, Pharmaceutica Acta Helvetiae , Volume 70, Issue 2, 1995, https :// doi.org/10.1016/0031-6865(95)00010-7 Nina Filipczak , Jiayi Pan, Satya Siva Kishan Yalamarty , Vladimir P. Torchilin , Recent advancements in liposome technology, Advanced Drug Delivery Reviews, Volume 156, 2020, 4-22, https :// doi.org/10.1016/j.addr.2020.06.022 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 24

25. THANK YOU! 17-11-2021 Department of Pharmaceutics, KMCH College OF Pharmacy 25