Evaluation of pilocarpine loaded gelatin particles for topical ophthalmic use

Gelatin particles containing pilocarpine HCl were prepared using a desolvation method. The influence of the gelatin type and the preparation pH on particle properties was studied. The drug entrapment amounted 44 to 57%, zetapotential was slightly negative. Particle size varied from 312 nm to 500 nm depending on preparation pH. Franz diffusion cell experiments showed a release approaching zero-order kinetics and a sustained release compared to an aqueous pilocarpine HCl solution.