SOLUBILITY KINETICS OF DRUGS STUDIED BY LALLS METHOD IN WATER SOLUTIONS WITH VARIOUS HYDROGEN ISOTOPE CONTENT

The kinetic evaluation of solubility of drug substances of different chemical and pharmacological groups (bendazol hydrochloride, lactose monohydrate and taurine) was conducted in aqueous solutions with different isotopic composition of hydrogen. The choice of solvent was made due to the fact that the replacement of purified water, containing 141,0 ± 0,9 ррm 21H(D) heavy isotope of hydrogen, to water with low content of 21H(D) can accelerate the solubility of the active process pharmaceutical ingredients (APIs), approximately in 1,5 times. The study was carried out by the laser light diffraction method, which is the basis of the Monograph.1.2.1.0008.15 SF RF XIII «Particle size distribution». In contrast to the existing methods of the pharmacopoeial analysis governing the visual assessment of the completeness of the solubility of the API, the laser diffraction method allows to get an objective assessment of the solubility of the API based on the change of the integral characteristics of dispersion over time