Quantitative Analysis of Microgram Quantities of Pilocarpine in Aqueous Solution

Evaluation of monolithic HPLC columns for various pharmaceutical separations: Method transfer from conventional phases and batch to batch repeatability

“…Solution b (Pilocarpic acid and isopilocarpic acid): Pilocarpic acid and isopilocarpic acid which are not commercially available were generated by base catalyzed hydrolysis in a way similar to [19]. To 5 ml of 1 mg/ml pilocarpine aqueous solution in a 25 ml volumetric flask, 100 l of concentrated ammonia was added and the mixture was heated in an oven to 90 • C for about 2 h. The mixture was allowed to cool to room temperature and then diluted to 25 ml with sample diluent.…”

“…Since only the configuration on one of the two chiral centers of pilocarpine changes the compounds are diastereomers. Isopilocarpine can then hydrolyse to form isopilocarpic acid [19].…”

Ultraviolet spectrometry

“…The reaction product was measured at 350 nm (72). Grignard reagents were determined by means of a reaction with acetophenone (143), vicinal diols by means of a reaction followed by measurement of the iodate formed (104), and pilocarpine and pilocarpic acid in aqueous solution by a kinetic method in which the hydrolysis of 2,4-dinitrophenyl acetate was measured by ultraviolet spectrophotometry (292).…”