抄録
Although the major ingredients in generic medicine are equivalent to those in brand-name medicine, generic medicines could be improved with regard to “easiness to take” and “availability of usage.” Such “advanced generic medicines” have been developed, for instance, taste-improved tablets, skin stimulation-reduced percutaneous absorbents, and solubility-improved preparations for injection. Gemcitabine, a deoxycytidine nucleoside analog, is the current standard chemotherapy used as first-line treatment for patients with pancreatic cancer. Gemcitabine preparations for injection are supplied as lyophilized dry powder contained in a vial, but the powder is slow to dissolve. It is thus necessary to thoroughly shake the vial after adding the solution and to confirm the presence or absence of insoluble particles. In this study, we investigated the solubility and dissolution of a brand-name and generic versions of gemcitabine preparation for injection. The solubility of gemcitabine, analyzed by HPLC, was different among the preparations. The average percentage of gemcitabine solubility in the brand-name preparation just after addition of saline was 78％. By contrast, those in generic preparations ranged from 57 to 98％. Furthermore, the dissolution time of lyophilized dry powder also differed significantly among the preparations. The brand-name preparation required 120 seconds, whereas the dissolution time of generic preparations ranged from 19 to 153 seconds. These results indicate that there are significant differences in the solubility and dissolution properties among the gemcitabine preparation for injection. The information may be useful for physicians or pharmacists when they select generic versions of gemcitabine preparation.
