In vitro study of a transfersomal gel preparation containing lynestrenol as a transdermal drug delivery system

Objective: Lynestrenol, a progestin hormone derivative, can suppress the productions of endogenous estrogen and progesterone hormones (ovaries) to prevent ovulation. In this study, lynestrenol was included in various transfersomal gel preparations for its transdermal delivery into fat (F)-and non-fat (NF)-containing skin tissues. Methods: Lynestrenol transfersome vesicles were prepared by encapsulating the drug in varied concentrations of phosphatidylcholine and Tween 80 using lipid film hydration method. Transfersomes were produced in the form of gel preparations at a dose of 0.15 mg/week and evaluated for their particle size, percentage of entrapment efficiency, and particle polydispersity. We performed in vitro evaluations of the formulation variants F0 (lynestrenol gel control) and F1 and F2 (lynestrenol transfersome gels) with variations in their phosphatidylcholine and Tween 80 content. We then performed an in vitro evaluation using the Franz diffusion cell (FDC) method for 12 h using all three formulations on F and NF-containing rat skin. Results: The FDC results demonstrated that lynestrenol was deposited into fat tissue and increased concentrations of Tween 80 (edge activator) increased lynestrenol delivery into this tissue. In addition, the percentages of drug penetration from NF rat skin treated with F0, F1, and F2 gels were 19.56%, 20.13%, and 20.56%, respectively, and those from F rat skin were 17.16%, 17.38%, and 17.50%, respectively. Conclusion: In vitro evaluation using the FDC method indicates that transdermal drug delivery through to fat tissues using transfersomes is a promising method for lynestrenol delivery.