PREPARATION AND EVALUATION IN-VITRO OF COLLOIDAL LIPOSPHERES CONTAINING PILOCARPINE AS ION-PAIR

Aqueous dispersions of solid lipospheres containing up to 7.5% pilocar pine as lipophilic ion pairs were submitted to a preliminary evaluatio n. The lipospheres (diameter 75-85 nm) consisted mainly of stearic aci d and egg lecithin; pilocarpine base was incorporated as ion pair with mono-octylphosphate, monodecylphosphate and monohexadecylphosphate. T he following parameters were investigated: stability constants (beta) and lipophilicity of the ion pairs, size, porydispersity and drug cont ent of the lipospheres, pilocarpine release in vitro. The preparations might constitute a promising vehicle for sustained ocular delivery of pilocarpine.