Track: Formulation and Delivery - Chemical - Drug Delivery - Nanoparticles
Category: Poster Abstract
Liposomes and Transferosomes for the Topical Delivery of Papain in the Treatment of Hypertrophic Scars
Purpose: Hypertrophic scars are firm, raised, pathogenic scars that are unappealing and often hinder the movement by interfering with flexion and extension across joints. It is characterized by the abundance deposition of collagen in the dermal layer of the skin. Proteolytic enzymes like papain has been utilized in the treatment of hypertrophic scars . Papain is extracted from Carica Papaya and has a high molecular weight of 23.5kDa with 212 amino acid residues. This high molecular weight restricts the passage if the molecule through stratum corneum when applied topically. To overcome this limitation liposomes, phospholipid-based vesicles are used. Liposomes are spherical vesicles of phospholipid bilayer with a capacity of encapsulating both hydrophilic and hydrophobic drugs. This drug delivery system can further be subjected to pharmaceutical modification in presence of an edge activator to form transferosomes . The major objective of this study is to deliver papain to dermal layer of the skin using liposomes or/and transferosomes. We hypothesize both liposomes and transferosomes can effectively encapsulate and deliver papain across the skin overcoming the stratum corneum barrier when applied topically. Methods: Liposomes were prepared using the thin-film hydration method. Soy lecithin and cholesterol were taken in 4:1 ratio. Papain was added to the lipids and the mixture was dissolved in ether. The solvent was evaporated by using rotary evaporator to obtain a thin film which was then dispersed in the phosphate buffer. It was further subjected to ultra-sonication to obtain liposomes. However, for the transferosomes, thin-film hydration method was applied using soy lecithin in combination with tween 80 to obtain deformable vesicles. The particle size of both the blank and papain loaded vesicles was further controlled using an Avanti Polar- Lipid extruder. The extruded particles were subjected to freeze drying after the addition of trehalose. The freeze-dried particles were characterized for their particle size and zeta potential using Brookhaven particle size analyzer, and Zetameter, respectively. Results: The particle size of the papain loaded transferosomes before extrusion was 249.4±48.20 nm with polydispersity of 0.187. The surface charge of the vesicles was found to be negative. The extruded papain loaded transferosomes had a particle size range of 154.43±3.24 nm with a polydispersity of 0.152. The zeta potential of these vesicles was found to be negative indicating negatively charged surface of the vesicles. Conclusion: Transferosomes prepared had particle sizes in nano ranges with negative surface charge. The particles after extrusion had smaller particle size and narrow polydispersity index. In vitro permeation behavior of these transferosomes through skin utilizing different skin models are under investigation. References:
Chen, Y. Y., Lu, Y. H., Ma, C. H., Tao, W. W., Zhu, J. J., & Zhang, X. (2017). A novel elastic liposome for skin delivery of papain and its application on hypertrophic scar. Biomedicine & Pharmacotherapy, 87, 82-91.
Cevc, G. (1996). Transfersomes, liposomes and other lipid suspensions on the skin: permeation enhancement, vesicle penetration, and transdermal drug delivery. Critical reviews™ in therapeutic drug carrier systems, 13(3-4).