Application of a sorbent based on hypromellose for the quantitative determination of procaine in pharmaceutical formulation

Abstract

Aim. The aim is to assess the selectivity and metrological characteristics of the spectrophotometric determination method of procaine in certain combined pharmaceutical preparations using a solid-phase extraction sorbent based on hypromellose. Material and methods. To obtain the solid-phase extraction sorbent, hypromellose and ethyl cyanoacrylate were used along with procaine hydrochloride and sodium hydroxide for the formation of active centers. The sorbent was prepared using a known method. The sorption capacity of the obtained sorbent samples for procaine was 10.2 1.0 g/g. Combined drugs containing procaine and its salts, such as "Menovazin," "Sulfocamphocaine," and "Otolorin," were selected for the study. Eluate optical density registration was performed using a SF-56 spectrophotometer (OKB SPECTR LLC). To evaluate the selectivity (specificity) of sample preparation in chromatographic separation of combined drugs, absorption spectra were registered in the wavelength range of 200-400 nm for eluates obtained using purified water and a 0.1 M hydrochloric acid solution. Procaine and benzocaine identification in the eluate was performed based on the presence of absorption maxima at wavelengths of 222 and 286 nm for benzocaine, and 228 and 292 nm for procaine, respectively. The statistical processing of experimental results and determination of metrological characteristics of the analysis method were carried out in accordance with OFS.1.1.0013 "Statistical Processing of results of physical, physicochemical, and chemical tests." Results. The selectivity of the spectrophotometric determination method of procaine in certain combined drugs using a solid-phase extraction sorbent based on hypromellose was demonstrated. Selective binding of the analyzed substance with active centers in the sorbent and stepwise elution with purified water and a 0.1 M hydrochloric acid solution during solid-phase extraction eliminates the interfering effect of pharmaceutical components during the UV-spectrophotometry of procaine. The use of a sorbent based on hypromellose leads to improved metrological characteristics and reduces the systematic error of the quantitative determination method by an average of 14.4%.