title: Analysis of pilocarpine and its trans epimer, isopilocarpine, by capillary electrophoresis.
abstract: Capillary zone electrophoresis was used for the separation of pilocarpine from its epimer, isopilocarpine, using coated fused-silica capillaries of 20 cm x 25 microm I.D., 8 kV running voltage, migration buffer of 0.1 M sodium dihydrogenphosphate pH 8, detection at 217 nm and injection by electromigration. Injections of aqueous, acid and basic solutions were compared. Linearity of the signal for pilocarpine hydrochloride up to 200 microg ml(-1) in 0.05 M hydrochloric acid was obtained, using naphazoline nitrate as internal standard. Optimization of migration buffer pH using coated silica capillaries of 50 cm x 50 microm I.D. showed that at pH 6.9 pilocarpine can be separated from ++isopilocarpine. Inclusion of beta-cyclodextrin in the buffer allows full baseline separation of both epimers. The method was applied to the analysis of a commercial ophthalmic pilocarpine solution.
authors.affiliation: Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, University of Ghent, Belgium.
authors.forename: W
authors.initials: W
authors.lastname: Baeyens
authors.forename: G
authors.initials: G
authors.lastname: Weiss
authors.forename: G
authors.initials: G
authors.lastname: Van Der Weken
authors.forename: W
authors.initials: W
authors.lastname: Van Den Bossche
mesh_terms: D002021:Buffers; D003505:Cyclodextrins / Q000737:chemistry; D004355:Drug Stability; D004586:Electrophoresis; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D009883:Ophthalmic Solutions; D010862:Pilocarpine / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D047392:beta-Cyclodextrins
chemical_list: D002021:Buffers; D003505:Cyclodextrins; D009883:Ophthalmic Solutions; D047392:beta-Cyclodextrins; D010862:Pilocarpine; C031215:betadex