이온강도 및 pH가 딜티아젬 서방정의 용출에 미치는 효과 = Effect of Ionic Strength and pH on the Dissolution Rate of Diltiazem Hydrochloride Modified Release Tablets

다국어 초록 (Multilingual Abstract)

Dissolution criteria for evaluating an equivalence of drugs should take into account a physicochemical property of each drug and/or a specific formulation of each preparation. The effect of acidity, ionic strength and buffer capacity of media on the dissolution profiles were examined using a diltiazem hydrochloride modified release tablet, a calcium ion cellular influx inhibitor. The dissolution rate was the fastest at pH 1.2, and the addition of NaCl did not affect its release pattern. By sharp contrast, NaCl and phosphate ions at pHs 6.8 and 8.2 led to a decrease of drug release. The decreasing rate was more conspicuous by addition of phosphate ions than by that of NaCl. This indicates that the composition of dissolution medium affects the solubility of test drugs, the physicochemical property of polymers used for a modified release, and dissolution profiles of a drug product. In conclusion, dissolution specification should consider acidity, ionic strength and buffer capacity of media.