Combinatorial Approach of Polymeric Patches and Solid Microneedles for Improved Transdermal Delivery of Valsartan: A Proof-of-Concept Study

Valsartan (VALS) is a first-line therapy for hypertension that belong to the Angiotensin II Receptor Blockers class. VALS is currently administered orally, but it is associated with its low bioavailability. The transdermal route can be an alternative to overcome this problem. However, this route has low permeation caused by the presence of stratum corneum on the skin. The use of permeation enhancers is needed. This study aims to determine the effect of PEG 400 concentration on physical characteristics and release of VALS from transdermal patch preparations and determine the effect of solid microneedles on VALS permeation. The transdermal patch formula was made using HPMC as a base and PEG 400 as a permeation enhancer with various concentrations. The patches were evaluated for their physical appearance, weight uniformity, thickness, moisture content, folding endurance, drug content, in vitro drug release, in vitro drug permeation, and ex vivo permeation test. The results showed that all formulations showed good characteristics for transdermal administration, and the use of PEG 400 could increase the permeation of VALS. Importantly, when combined with solid microneedles, the permeation of VALS was significantly improved. To conclude, the combination of VALS patch transdermal and MNs can increase the amount of VALS permeated.