Improved transdermal delivery of valsartan using combinatorial approach of polymeric transdermal hydrogels and solid microneedles: an ex vivo proof of concept investigation

Valsartan (VAL) is used as a first-line agent to treat hypertension. However, VAL exhibits poor absorption and low bioavailability when administrated orally. To overcome these issues, VAL transdermal gel was developed in this study, where Carbopol was used as the gel matrices. Additionally, solid microneedles (Dermarolleh with various needle lengths were combined with transdermal gel to improve its permeation across the stratum corneum as a skin barrier. Developed formulations were further evaluated for various parameters, including pH, viscosity, spreadability, extrudability, gel strength, drug content, ex vivo permeation, in vitro release, occlusivity, and hemolysis. The results showed that all formulations exhibited desired physical characteristics without any potential to cause toxicity. Moreover, this approach showed that using microneedles could significantly enhance the permeation of VAL up to 3 folds compared to untreated skin. The use of microneedles 1.5mm was found to be the optimum combination to improve VA permeation without affecting skin integrity. As much as 1.69 +/- 0.004 mg of VAL permeated after 8h. Finally, it could be concluded that this work had successfully developed a new approach for VALS drug delivery and could potentially show a significant impact on the treatment of hypertension. Further in vivo work should be considered.

Automated summary

This study developed a new transdermal gel for the treatment of hypertension by combining it with solid microneedles, which significantly enhanced the permeation of valsartan without affecting skin integrity. This approach could have significant implications for drug delivery.