Development and validation of HPLC method for determination of clotrimazole and its two degradation products in spray formulation.
A novel simple isocratic HPLC method with UV detection for the determination of three compounds in spray solution (active component clotrimazole and two degradation products imidazole and (2-chlorophenyl)diphenylmethanol) using ibuprofen as an internal standard was developed and validated. The complications with different acido-basic properties of the analysed compounds in HPLC separation - while clotrimazole has pK(a) 4.7, imidazole has pK(a) 6.9 compared to relatively more acidic (2-chlorophenyl)diphenylmethanol - were finally overcome using a 3.5mum Zorbax((R)) SB-Phenyl column (75mmx4.6mm i.d., Agilent Technologies). The optimal mobile phase for separation of clotrimazole, degradation products imidazole and (2-chlorophenyl)diphenylmethanol and ibuprofen as internal standard consists of a mixture of acetonitrile and water (65:35, v/v) with pH* conditioned by phosphoric acid to 3.5. At a flow rate of 0.5mlmin(-1) and detection at 210nm, the total time of analysis was less than 6min. The method was applied for routine analysis (batch analysis and stability tests) in commercial spray solution.
Hájková
Renata
R
Department of Analytical Chemistry, Faculty of Pharmacy, Charles University, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.
Sklenárová
Hana
H
Matysová
Ludmila
L
Svecová
Petra
P
Solich
Petr
P