USING THE HPLC METHOD TO STUDY A MIXTURE OF SUBSTANCES CONTAINING ACYCLOVIR AND HYDROCORTISONE

Abstract

The article is devoted to the study of a mixture of substances containing acyclovir and hydrocortisone by the method of highperformance chromatography (HPLC), as a result of which the chromatography conditions were modified and unacceptable impurities were carefully investigated. The purpose of the work. Investigate alternative conditions for chromatography using the HPLC method of a mixture of hydrocortisone and acyclovir substances, which could demonstrate a higher identification ability during the determination of impurities in their composition; to modify research methods to create optimal conditions for protection against chemical degradation of the structure of hydrocortisone and acyclovir substances – potential ingredients of the pharmaceutical composition. Methodology. Acyclovir (ACV) and hydrocortisone (HCT) are biologically active substances that are used as active agents and additional components in the creation of pharmaceutical compositions in the form of ointments, tablets, creams, etc. During the synthesis of substances, by-products of the reaction, accompanying impurities and related substances, as well as molecular degradation products are formed, the presence of most of which is not regulated by the State Pharmacopoeia of Ukraine (SPU), European Pharmacopoeia (Eur.Ph.) and British Pharmacopoeia, and the analysis is performed by the method of liquid chromatography. These substances negatively affect the quality of substances and, accordingly, medicines. During chromatographic studies of pharmaceutical compositions with acyclovir and hydrocortisone, correctly selected chromatographic conditions are important, since the use of aggressive reagents or violation of the temperature regime, the presence of unacceptable impurities in the composition of chemical reagents can lead to the destruction and chemical degradation of both the substance and the pharmaceutical composition. Scientific novelty. Obtaining new data on the possibility of using modified HPLC chromatography conditions for a mixture of acyclovir and hydrocortisone substances will allow the introduction of the HPLC method into the practice of pharmaceutical analysis of these chemicals, since in the developed research conditions, molecules of acyclovir and hydrocortisone are not subject to chemical degradation. Materials and methods. Samples of acyclovir and hydrocortisone substances, pharmacopoeial standard samples of SPU of acyclovir and hydrocortisone; HPLC, Agilent 1260 Infinity II chromatograph with UV detector, INERTSIL ODS-3V column, 250x4.6x5 with a temperature of 25˚С; column – Waters Xbridge C18, 250x4.6x5 with a temperature of 25˚С; flow – 0.8 ml/min, 1.0 ml/ min; injection volume – 10 μl; chromatography time – 56-60 min; UV detection at 254 nm; for the determination of extraneous impurities – accompanying substances by the HPLC method, reagents were used: acetonitrile (pure for HPLC), water (pure for HPLC), dipotassium hydrogen phosphate, orthophosphoric acid; computer analysis – OpenLab CDS program. Conclusions. The effect of modified HPLC chromatography conditions was studied in comparison with the generally accepted pharmacopoeial methods of research of accompanying impurities in the composition of acyclovir and hydrocortisone substances, which provide protection of their structure from chemical degradation by creating optimal conditions for preserving the chemical structure. The peak of hydrocortisone is located with Rt in the interval 24.398-24.570 min, compared to the standard value in the interval Rt 24.401-24.566 min, and unidentified impurities were detected: I (Rt=12.533 min), 1 (Rt=10.101 min), 2 (Rt=13.266 min); the acyclovir peak is located with Rt in the interval 11.339-11.389 min, compared to the standard Rt value in the interval 11.294-11.310 min.