Formulation and evaluation of transdermal patches of an Antifungal drug
Hemalatha PC, V Chandrakala
Background: Bioavailability of Terbinafine HCl tablets as a result of the first-pass metabolism is approximately 40%.A single oral dose of 250mg Terbinafine results in a peak plasma concentration (Cmax) of 0.83μg/ml within 2h of administration. The absorption of half-life is 0.8h and the distribution half- life is 4.6 h. This Originates the Transdermal drug delivery as an alternative route of administration for such drugs which can bypass the hepatic first-pass metabolism.Objective: The objective of the present study was to compare the release effect of Terbinafine HCl from different polymeric (natural and synthetic) patches prepared using different permeation enhancers (natural and synthetic) and varying concentrations. The best polymer and permeation enhancer was selected based on the release of the drug from the patches.Materials and Methods: Polymers such as HPMC, Chitosan, and Glycerin was used as a plasticizer. Enhancers used were Eucalyptus oil and Dimethyl Sulfoxide. Transdermal patches were prepared by using the solvent casting technique. FTIR was studied to estimate the incompatibility. Patches were evaluated for physicochemical Characteristics like thickness, weight variation, folding endurance, moisture loss, moisture absorption, drug content, and In-vitro diffusion studies.Results: The results obtained showed no physical-chemical incompatibility between the drug and the polymers. HPMC was found to be a suitable polymer compared to Chitosan in preparation of transdermal patches. From the evaluation of patches, DMSO appears acceptable permeation enhancer compared to Eucalyptus oil as a natural origin. F19 containing 20% of DMSO was considered as the best formulation for the transdermal delivery of TH. Conclusion: Transdermal patches were successfully prepared for TH and their evaluation studies of each dosage form revealed that topically applied TH patch possess immense potential to control the release rate of medicament to improve the bioavailability as well as patient compliance.