Two-layer patches composed of PVA-Pectin cryogels was designed for control release of enrofloxacin

MARTINEZ YANINA; PIÑUEL, LUCRECIA; CASTRO GUILLERMO R; JAVIER D, BRECCIA

Trivandrum

Conferencia; International Conference on New Horizons in Biotechnology; 2011

Cryogel patches composed of polyvinyl alcohol and pectin (PVA-P) blend were produced by repeating cycles of freeze–thawing. Since the pH in mammal´s skin is found in the range of 4.2 to 5.6, the release of enrofloxacin entrapped in the PVA-P cryogel matrix was evaluated at pH 5.5. The PVA cryogel has zero-order kinetic for enrofloxacin release and liberate 69.7% of the antibiotic in 4.5 h at 37°C. To slow down the quinolone release rate, high metoxylated pectin was added into the cryogel. This biopolymer showed a high binding capacity to the cationic form of the antibiotic. When 5.0 µg/ml of enrofloxacin were loaded, only 3.7% was released from a patch containing 1.0% (w/v) pectin after 4.5 h. Therefore, a two layer-system was designed to modulate the releasing rate of the antibiotic. In this system the top film was loaded with NaCl (1.5M) and the diffusion of the electrolyte to the bottom film containing the drug improved the release rate (24.0% in 4h). The release rate of enrofloxacin was found dependent of NaCl concentration in the upper gel layer. Consequently the new two-layer cryogel system showed attractive features for transcutaneous drug delivery.