PBAT/PLA Films and Supercritical Impregnation of Caffeine for Potential Application in Anticellulite Tools

Topical administration is the preferred route for the controlled release of active compounds since it reduces side effects typical of other administration methods. The use of polymer blends is a way to modulate drug release from a topical device. The blends ensure modulation of a wide range of properties, such as mechanical properties, water sorption, and degradation. This paper proposes blends of poly(lactide acid) (PLA), and Poly(butylene adipate‐ co ‐terephthalate) (PBAT), for the topical release of caffeine, a molecule with anti‐inflammatory, antioxidant, and anticellulite activities. PBAT/PLA blends are optimized for compatibility between the two polymers, mechanical properties, and drug release rate. Blends with a higher amount of PBAT show the best performance regarding polymer compatibility. The blends undergo supercritical CO 2 ‐assisted caffeine impregnation. This process assures homogeneous dispersion of caffeine into the polymer matrix. The ratios 45/55 and 55/45 PBAT/PLA show the best performance in terms of caffeine release (complete caffeine release within 25 h). Caffeine is released into three steps: a burst effect due to the caffeine dispersed over the film surface, a slower release due to the caffeine dispersed in the polymer matrix, and a fast release due to the increase of polymer degradation rate induced by caffeine presence.