LC method for the simultaneous determination of R-timolol and other closely related impurities in S-timolol maleate: Optimization by use of an experimental design
LC optimization; experimental design; timolol maleate; enantiomeric purity; related substances
Abstract :
[en] A liquid chromatography (LC) method using cellulose tris(3,5-dimethylphenylcarbamate) (5 mum) as chiral stationary phase (CSP) and a mixture of hexane, 2-propanol, and diethylamine as mobile phase was developed for the simultaneous determination of R-timolol and other potential related substances in S-timolol maleate samples. An experimental design was elaborated in order to test the effects of the different selected factors. Three factors were studied simultaneously, namely the concentrations of 2-propanol and diethylamine as well as the column temperature. The effects of these factors were evaluated statistically. Optimal LC conditions were then deduced by applying a multicriteria decision making approach, namely Derringer's desirability function, for the responses of interest. The developed LC method was compared to the European Pharmacopoeia method and was applied to the determination of R-timolol and other related substances in several samples of S-timolol maleate from different sources.
Crommen, Jacques ; Université de Liège - ULiège > Département de pharmacie > Analyse des médicaments
Language :
English
Title :
LC method for the simultaneous determination of R-timolol and other closely related impurities in S-timolol maleate: Optimization by use of an experimental design
(1996) ICH Topic Q 2 B, Note for Guidance on Validation of Analytical Procedures: Methodology, , 6 November
(1999) ICH Harmonized Tripartite Guideline, Technical Requirements for Registration of Pharmaceuticals for Human Use, Impurities in New Drug Substances, , 7 October