title: Photochemical stability of nimesulide.
abstract: HPLC and TLC methods for monitoring of the photochemical stability of nimesulide are presented. Solution of nimesulide sodium salt was exposed to the light of wavelengths 254 nm. The presence of degradation products (2-phenoxy4-nitroaniline and methanesulfonic acid) was observed. In the exposed sample, 2-phenoxy4-nitroaniline was detected by HPLC analysis and sulfonic acid was detected by TLC analysis. An isocratic HPLC chromatographic condition was described for determination of nimesulide in a presence of its degradation product. The sample was analysed on Separon SGX, C(18), 250 x 4.6 i.d. 7 microm analytical column. The mobile phase was consisted of a mixture of acetonitrile and ammonium phosphate (pH 7.9; 0.02 M) (35:65 v/v). UV detector was performed at 245 nm. Propylparaben was employed as an internal standard. Standard area response was linear respect to concentration of nimesulide over range 150-500 microg/ml. As a validation of the method, the accuracy and between-day precision were done. The detection limit of 2-phenoxy4-nitroaniline was 0.12 microg/ml. The solvent system for TLC analysis was consisted of ethylacetate and cyclohexane (45:55), the samples were plotted on silica gel UV-254 nm. UV lamp (254 nm) and the chemical detection were used.
authors.affiliation: Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, 50005, Hradec Kralove, Czech Republic. kovarikova@faf.uni.cz
authors.forename: Petra
authors.initials: P
authors.lastname: Kovaríková
authors.forename: Milan
authors.initials: M
authors.lastname: Mokrý
authors.forename: Jirí
authors.initials: J
authors.lastname: Klimes
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002855:Chromatography, Thin Layer / Q000379:methods; D004355:Drug Stability; D010777:Photochemistry; D013449:Sulfonamides / Q000032:analysis* / Q000737:chemistry*
chemical_list: D013449:Sulfonamides; C012655:nimesulide