Simultaneous determination of Timolol Maleate and Pilocarpine Hydrochloride in ophthalmic solutions by first derivative UV spectrophotometry and PLS-1 multivariate calibration.

SATUF, M. L.; ROBLES, J. C.; GOICOECHEA, H. C.; OLIVIERI, A. C.

ANALYTICAL LETTERS

Taylor & Francis, Inc.

Lugar: Philadelphia, Estados Unidos; Año: 1999 vol. 32 p. 2019 - 2033

0003-2719

The use of UV spectrophotometry (first-derivative/zero-crossing and zero-order spectra/multivariate calibration) is reported for the analysis of two miotic agents in ophthalmic solutions. The resolution of these mixtures has been accomplished without prior separation or derivatisation by using: 1) first-derivative measurements at two appropriate zero-crossing points: l1 = 222 nm, where the absorption corresponding to excipients is negligible, and l2 = 307 nm, where the contribution of pilocarpine and excipients to the overall absorption is negligible, and 2) partial least squares (PLS-1) regression analysis of zero-order spectral data. Although the components show an important degree of spectral overlap, they have been simultaneously determined with high accuracy, and with no interference from ophthalmic solution excipients.