Determination of vaginal gel composition on the basis of biopharmaceutical and rhelogical researches

Abstract

Aim. The aim of the work is to determine the content of gelling agent in the composition of the vaginal gel for the treatment of urogenital symptoms during the period of women's hormonal instability and to determine the concentration of a non-aqueous solvent propylene glycol in the gel to provide release of the active ingredient, resveratrol. Materials and methods. As objects of the study samples of gels with resveratrol and hyaluronic acid with varying concentrations of gelling agent aristoflex AVC and non-aqueous solvent propylene glycol have been taken. Biopharmaceutical studies by equilibrium dialysis through a semipermeable membrane for 6 hours were performed to select propylene glycol concentration. The optical density of the samples obtained was determined using Evolution 60-S spectrophotometer. The concentration of the gelling agent was determined by rheological performance using the Rheolab QC rheometer, by Anton Paar, Austria. Results. In the course of the study, a comparison was made between resveratrol release from samples with propylene glycol concentration of 10% and 15%. At 6th hour of the experiment, a larger amount of resveratrol, which has passed to the solution, was observed in a sample with propylene glycol concentration 15%. It has been established that an increase in the concentration of propylene glycol contributes to an increase in the rate of the active ingredient release from gel samples. Thus, for further studies on the development of vaginal gel composition, the concentration of non-aqueous solvent was chosen to be 15%. At the next stage, the choice of gel-former concentration in the gel was made. In the course of the study, rheological properties of samples with gel-former concentration of 1%, 1.5% and 2% have been compared. The obtained rheograms of gel samples indicate that all systems are coagulating with a pseudoplastic flow type and a certain degree of thixotropy. A sample with the concentration of 1% is a liquefied system that has practically no structure, as evidenced by the large difference between initial and final viscosity. An increase in the concentration of gelling agent to 2% leads to a strengthening of the structure. The sample with Aristoflex concentration 1,5% has optimal rheological parameters that can provide high biological availability of active substances. Conclusions. It has been established that the optimal concentration of PG, which contributes to maximal release of the active substance, is 15% of the total mass of the sample. According to the results of rheological research, the rational content of the gel-former in the gel is 1,5%