Multivariate Optimization and Validation of a CE method for Simultaneous Analysis of Dorzolamide Hydrochloride and Timolol Maleate in Ophthalmic Solution

Abstract

A fast, accurate, precise, and sensitive capillary electrophoretic method has been developed for simultaneous analysis of dorzolamide hydrochloride and timolol maleate in eye drops. Response-surface methodology with a central composite design was used for optimization of buffer pH, applied potential, and temperature. Capillary electrophoresis at 25°C with NaH 2 PO 4 buffer (pH 6.00, 0.025 M), and an applied potential of 20 kV was found to be suitable, and under these optimum conditions, dorzolamide hydrochloride and timolol maleate were separated in approximately 3 min. This method was validated and successfully applied to a pharmaceutical preparation, ophthalmic solution, and the results were compared with those from a spectrophotometric method described in the literature.

Dual design spaces for micro-extraction together with the core–shell chromatographic determination of dorzolamide and timolol in rabbit plasma: an example of quality by design method development

“…Consequently, the proposed method acquired higher sensitivity than the methods reported for their simultaneous determination. [21][22][23][24][25][26][27][28][29][30][31] Regarding the other reported methods for their separate determination in plasma, it was found to be superior to many of them. 34,[36][37][38][39][40][41] 3.3.2.…”

“…In this context, there is a need for monitoring their plasma levels after their ocular instillation with the aid of sensitive analytical methods. Nevertheless, few reports detail their simultaneous quantification depending on the use of UV-spectrophotometry, [21][22][23] thin layer chromatography (TLC), 21 capillary electrophoresis (CE) 24 and high-performance liquid chromatography (HPLC). [25][26][27][28][29] However, these methods lack enough sensitivity, which enables their quantification in biological fluids.…”

New RP-HPLC Method Development and Validation for Dorzolamide in Ophthalmic Dosage Form

“…These methods include reversed-phase high-performance liquid chromatography (RP-HPLC) [2–10], spectrophotometry [11–14], capillary electrophoresis [15], and others [7, 13, 16]. Both the British Pharmacopoeia [1] and United States Pharmacopoeia [17] describe liquid chromatography methods for the determination of the drug in pharmaceutical dosage forms.…”

Stability-Indicating HPTLC-Densitometric Method for Estimation of Dorzolamide Hydrochloride in Eye Drops

“…The literature review reveals that several methods have been reported for the estimation of DORZO in biological fluids [2][3][4][5], and there are some methods reported by HPLC [6][7][8][9], spectroscopy [10,11], and capillary electrophoresis [12], and there are some methods reported for estimation of DORZO in pharmaceutical formulation [13][14][15]. According to current good manufacturing practices, all drugs must be tested with a stability-indicating assay method before release.…”