Abstract
The effect of antacids on the dissolution behavior of tetracycline hydrochloride and methacycline hydrochloride from commercial capsules was studied. The dissolution of the tetracyclines was found to be markedly retarded by antacids such as aluminium silicate and magnesium trisilicate. An attempt was made to elucidate the mechanism of this effect. The results suggest that the effects of antacids on the dissolution may be due to the adsorption of the drugs on antacid particles as well as to the increased pH of the medium. A study was also carried out to determine the influence of stomachics using Cinnamomi Cortex as a test material. In dissolution experiments on commercial capsules, a significant dissolution inhibition by the stomachic was found.
