A NEW POLY(VINYL CHLORIDE) MATRIX MEMBRANE-ELECTRODE FOR MANUAL AND FLOW-INJECTION DETERMINATION OF PILOCARPINE IN SOME PHARMACEUTICAL PREPARATIONS

A novel pilocarpinium ion selective membrane electrode is prepared, ch aracterized and used in pharmaceutical analysis. The electrode system incorporates a PVC membrane with pilocarpine-reineckate ion pair compl ex as an electroactive material. The electrode exhibits a fast near-Ne rnstian response for 10(-1)-4x10(-5)M pilocarpine over the pH range 4- 6.5. The electrode displays a good selectivity for pilocarpine with re spect to a number of foreign cations. Pilocarpine in various pharmaceu tical preparations is determined either by direct potentiometry or pot entiometric titration with NaTPB using the proposed sensor. Pilocarpin e-reineckate membrane is also used in a flow through sandwich cell as a detector for flow injection determination of pilocarpine. Results wi th an average recovery of 99% and a relative standard deviation of +/- 0.3% are obtained The data compare favorably with those obtained by t he standard US Pharmacopeia method.