HIGH-PRESSURE LIQUID-CHROMATOGRAPHIC DETERMINATION OF CHLORHEXIDINE ACETATE AND SOME TROPANE ALKALOIDS IN EYE DROPS

A method for the determination of chlorhexidine acetate in eye drops has been developed. Samples are assayed by direct injection on a C8 reverse phase column. The mobile phase is methanol 80% v/v, water 20% v/v with 0005M heptane sulphonic acid sodium salt at pH 3–5 as an ion‐pairing agent. When run on this system the chlorhexidine is well separated from/7‐chloroaniline, its major breakdown product. This method also allows the alkaloids to be determined by direct injection using approximately methanol 50% v/v, water 50% v/v with the ion‐pairing agent at pH 3–5. The procedure is to first assay the alkaloids and then by adjusting the solvent to methanol 80% v/v water 20% v/v and re‐injecting the samples, the chlorhexidine in the eye drops is determined. The samples are detected using a variable wavelength spectrophotometer. Copyright © 1979, Wiley Blackwell. All rights reserved