In-vitro study of physostigmine salicylate and pilocarpine hydrochloride release from different gel formulations.

Effect of methylcellulose and polyethylene glycol (PEG1 and PEG2) gel formulations on in-vitro release of combination of 0.25% w/w physostigmine salicylate and 1% w/w pilocarpine hydrochloride was investigated in comparison with a fatty base containing the same drugs by using a stationary dialysis technique. The results showed that the release of both drugs was very slow from the fatty base while a maximum release was attained from methylcellulose gel formulation followed by PEG1 and then PEG2 gel formulations as indicated by the calculated area under curves (AUC) for the amounts of drugs released from different formulations.