Optimized vinpocetine-loaded vitamin E D-α-tocopherol polyethylene glycol 1000 succinate-alpha lipoic acid micelles as a potential transdermal drug delivery system: in vitro and ex vivo studies

BACKGROUND: Vinpocetine (VNP), a semisynthetic natural product, is used as a vasodilator for cerebrovascular and age-related memory disorders. VNP suffers from low oral bioavailability owing to its low water solubility and extensive first-pass metabolism. This work aimed at utilizing D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and alpha lipoic acid (ALA) to develop efficient micellar system for transdermal delivery of VNP. MATERIALS AND METHODS: VNP-TPGS-ALA micelles were prepared, characterized for particle size using particle size analyzer, and investigated for structure using transmission electron microscope. Optimization of VNP-TPGS-ALA micelles-loaded transdermal films was performed using Box–Behnken experimental design. The investigated factors were percentage of ALA in TPGS (X(1)), citral concentration (X(2)), and propylene glycol concentration (X(3)). Elongation percent (Y(1)), initial permeation after 2 hours (Y(2)), and cumulative permeation after 24 hours (Y(3)) were studied as responses. RESULTS: Statistical analysis revealed optimum levels of 16.62%, 3%, and 2.18% for X(1), X(2), and X(3), respectively. Fluorescent laser microscopic visualization of skin penetration of the optimized transdermal film revealed marked widespread fluorescence intensity in skin tissue after 0.5, 2, and 4 hours compared with raw VNP transdermal film formulation, which indicated enhancement of VNP skin penetration. CONCLUSION: The obtained results highlighted the potentiality of VNP nanostructure-based films for controlling the transdermal permeation of the drug and improving its effectiveness.