Transdermal patch based on pressure-sensitive adhesive: the importance of adhesion for efficient drug delivery

The development of transdermal patches with sufficient adhesion for consistent and extended drug delivery remains a challenging task. Challenges in adhesion stem from the complex interplay among PSAs, permeation enhancers, active pharmaceutical ingredients (APIs), and other excipients in current patch compositions, further complicated by variations arising from dermatological factors. These intricacies significantly impede the consistent effectiveness of patches. Progress in the exploration of new PSA polymers, in conjunction with innovative patch compositions, is crucial for establishing an optimal equilibrium between drug utilization rate, drug-loading, drug release, and adhesion, thus effectively addressing the challenges related to adhesion.