| Abstract [eng] |
Aim of the work – to evaluate the influence of factors to stability of different concentration dexpanthenol aqueous solutions and emulsifying systems (O/W). Objects of research – dexpanthenol aqueous solutions of different concentration; emuldion system (O/W) made with PEG – 20 glyceryl triisostearate and propylene glycol. Tasks of research – to evaluate the pH value, temperature mode and storage time influence to the stability of 0,5 – 0,6 % dexpanthenol aqueous solutions; to compare different PEG – 20 glyceryl triisostearate and propylene glycol concentration influence to the emulsion system formation; to compare 400 – 800 rotations per minute (rpm) mixing rate influence to emulsion system oil droplet size; to evaluate dexpanthenol influence to emulsion system lypophilic and hydrophilic phase aggregate stability, to oil droplets size and to emulsion system texture. Dexpanthenol is an optically active substance, and its concentration in aqueous solutions is measured by a polarimeter. The pH value is measured by the pH - meter. Dexpanthenol aqueous solutions with different pH values stability was compared and it was found that the minimum dexpanthenol concentration reduction was observed with pH value 6,0±0,2 and the maximum reduction in acid and in alkaline environments (p<0,05). Dexpanthenol aqueous solutions are stable at the temperature of 21±2 ⁰C. It was found that increasing PEG – 20 glyceryl triisostearate and propylene glycol concentration from 5 % to 20 % stability of emulsion system increased. When PEG – 20 glyceryl triisostearate concentration is 20 % emulsion system is stable, when concentration exceeds 20 % - stability decreases significantly. Following the centrifuge test it was found that 5 % propylene glycol concentration improves emulsion system stability 1,15 times (p<0,05). Increasing the mixing rate from 400 – 800 rpm, emulsion system (O/W) dispersion value increases significantly and the size of oil droplets diminishes and a heating - cooling cycle study showed increases thermodynamic stability. A stable emulsion system with dexpanthenol is formed after 3 days from emulsion system. Emulsion system with dexpanthenol pH value is 5,9±0,2. It was found that emulsion system dispersivity is 1,1 times (p<0,05) superior to dispersivity of the emulsion system without dexpanthenol. Dexpanthenol significantly influences emulsion system texture: increase of density, adhesion and viscosity index (p<0,05). Emulsion system with dexpanthenol could be used for irritated, prone to dermatitis skin care. It is appropriate to increase the emulsion system mixing rate to extend the stability trials, toxicological studies and research in vivo. |
