Biopolymeric nifedipine powder for acceleration of wound healing.

Nine biodegradable polymeric powders of chitosan; with or without gelatin; containing nifedipine (NF), were prepared via spray drying for acceleration of wound healing. The angle of repose of powders ranged from 30° to 40° for F(3) and chitosan/gelatin (C(2)), respectively. Upon spray drying, the mean particle size (PS) of chitosan was greatly reduced from 294 to 3.4 μm, while all formulae showed a PS near 3 μm. Specific surface area of the powders ranged from 0.06 × 10(5) to 2.03 × 10(5)cm(2)g. Powders exposure to glutraldehyde (GA) vapors gave smaller particles with higher densities with F(4) showing a mean PS of 0.4 μm. NF dissolution pattern in PBS, was highest from F(2) with 33% released after 30 min while F(3) showed only 4.5% NF released after the same period. Exposure to GA showed a reduction in NF release especially with F(5) showing 30% release after 3h. Tensile strength of 12 days-post incision wound in rats showed a maximum value of 4.7 kg cm(-2) for F(3) compared with 3.3 kg cm(-2) for the control. Excision wounds treated with F(3) also showed a fully developed epithelium with normal keratinization, and an average wound contraction of 99% compared with 79.5% for the control.