Optimization of L-arginine and thiotriazoline compound analysis by high-performance liquid chromatography method

Abstract

Cardiovascular diseases are the leading cause of death and disability in most countries of the world. Therefore, the crucial task of pharmacy and medicine is the creation of drugs for the treatment of these pathologies. As a result of pharmacological studies, the optimal ratio of L-arginine with thiotriazoline – 4:1 was found. It was proposed to use modern, high-precision method of high-performance liquid chromatography (HPLC) to determine the active substances in the dosage form. Objective. The purpose of our study is to develop a method for the simultaneous determination of L-arginine and thiotriazoline standardization in model mixture by high-performance liquid chromatography, in particular the selection of the mobile and stationary phase. Materials and methods . L-arginine (manufactured by Sigma-Aldrich, China), thiotriazoline (manufactured by the State Enterprise Chemical Reagents Plant of the Scientific and Technological Complex Institute of Single Crystals of the National Academy of Sciences of Ukraine) was used for the study. The studies were carried out using a modular BISCHOFF HPLC system (BISCHOFF Analysentechnik GmbH, Germany) with a Lambda 1010 spectrophotometric detector. Results: At first, the determination was carried out on the reverse phase, with L-arginine practically not retained (coming out at the “dead volume”), and the use of cyanated phase did not significantly affect the retention of L-arginine. Further, the retention time of L-arginine increased slightly under ion-pair chromatography on the reversed phase, in determining and using the eluent with tetrabutylammonium. The most acceptable result was obtained by using an ion buffer reagent acid buffer – 0.05 % solution of trifluoroacetic acid. Conclusion. Thus, according to the obtained results, we believe that the use of an acid buffer – 0.05 % solution of trifluoroacetic acid is one of the promising ways for the simultaneous determination of L-arginine with thiotriazoline in the model mixture along with the ion-pair reagent. In the future, we are going to use this technique for the standardization of a combined drug which includes L-arginine and thiotriazoline, in solid and liquid dosage forms.