Transdermal Patch With Crosslinked Acrylic Adhesive Matrix

The patent changes the chemical parameters of the adhesive system by introducing a specific crosslinking mechanism. The adhesive composition includes a polymer with carboxyl groups that crosslink in the presence of crosslinking agents (such as silane crosslinkers or carbodiimide crosslinkers), forming a gel network structure. This crosslinking transformation allows the adhesive to maintain its bonding properties even at high drug loads (up to 40-50% w/w nitroglycerin), resolving the contradiction between drug quantity and adhesive reliability.

By implementing crosslinking in the adhesive layer, the patent achieves a significant increase in drug release capacity per unit area. The crosslinked gel structure creates a more efficient drug reservoir and release mechanism, allowing adequate nitroglycerin delivery (10-20 mg/day) from a compact patch size (5-10 cm²), thereby maintaining ease of operation while ensuring sufficient drug release.

The patent extracts and eliminates the need for absorption enhancers from the formulation. Instead of using traditional permeation promoters (such as fatty acids, alcohols, or surfactants) that cause skin irritation, the invention relies on the crosslinked adhesive gel structure itself to facilitate controlled drug release and permeation. The crosslinked network provides a favorable microenvironment for drug diffusion through the skin without requiring irritating enhancement agents, thus improving permeation while avoiding skin irritation.