The administration of pioglitazone as an oral therapy is restricted due to various challenges. The aim of the current investigation was to evaluate the suitability of pioglitazone in adhesive transdermal patch as an alternative delivery system, in order to improve therapeutic delivery. Drug in adhesive pioglitazone (2% w/w) transdermal patch were optimized for drug release, suitable adhesive, and skin permeation enhancer. The selected patch was examined for drug-loading capacity and the patch with greater pioglitazone (6% w/w) was evaluated in rat models. The release of pioglitazone was influenced by the tested adhesive and was shown to be significantly higher (p < 0.001) with patch, prepared using Duro-Tak 87-2516. The ex vivo permeation results substantiate the release data as a greater transdermal flux (15.67 ± 2.35 µg/cm2/h) was demonstrated in patch fabricated with Duro-Tak 87-2516. Skin penetration enhancers promoted the ex vivo transdermal delivery of pioglitazone, and was ~2 folds (p < 0.0001) higher with propylene glycol, as compared to patch without enhancer. The maximum solubility of pioglitazone in Duro-Tak 87-2516 was found to be 6% w/w. Increasing the drug content in patch enhanced the transdermal flux and was highest when the pioglitazone level was 6% w/w (72.68 ± 5.76 µg/cm2/h). In vivo pharmacokinetic data demonstrate that the AUC0-α in transdermal application (13,506.51 ± 1649.92 ng·h/mL) was ~2 times higher (p < 0.0001) as compared to oral dosage form. In conclusion, the promising results observed here signifies that developed patch could be a viable alternative for oral therapy of pioglitazone.
Keywords: Duro-Tak; flux; permeation enhancer; pharmacokinetics; rat; release.