Stability of thiamine hydrochloride in liquid formulations

ABSTRACT

The stability of thiamine hydrochloride in aqueous media at 25, 37 and 60C, for 6 months was studied. In pure distilled water, thiamine hydrochloride was found to be stable for 6 months at 25C, while at elevated temperature, the residual% values were 85.0 and 66.2% at 37 and 60C, respectively. In the presence of light, appreciable loss of potency was observed in less than 3 months. The effect of McIlvain and phosphate buffers at different pH values have been also investigated. Maximum stability was found at pH 4 to 4.5 McIlvain buffer at 25 and 37C. On the other hand, the effect of certain additives commonly used for formulation of antidiarrheal containing thiamine hydrochloride, demonstrated that, at either 37 or 60C Aerosil 200 and bismuth oxycarbonate did not cause any significant decrease in potency. In contrast, veegum reduced the potency to 25.5 and 15.0% at 37 and 60C, respectively, after 3 months. At 37C, thiamine hydrochloride was stable for one month in presence of kaolin, while at 60C a significant decrease in its potency was found. In presence of mixture of vitamins B, ferric ammonium citrate, calcium pantothenate and calcium gluconate, the rate of decomposition of thiamine hydrochloride was highly accelerated