- 医療薬学 (ISSN:1346342X)
- vol.40, no.3, pp.135-146, 2014-03-10 (Released:2015-03-10)
This study determined the effects of long-term storage under various conditions after opening press through package (PTP) sheets on the stability of each tablet formula of statin for treatment of dyslipidemia and clarified the difference in stability between brand-name drugs and generic drugs.It was demonstrated that opened Crestor® tablets were stable for one year under the conditions of diffused light at room temperature and shielded light at room temperature. Although the content of rosuvastatin in ground Crestor® tablets was greatly decreased after only 1 month under the condition of diffused light, it was stable for at least 3 months under shielded light, indicating that shielded light is necessary for storage of ground Crestor® tablets. Of the four tablet formulae of simvastatin tested, only Lipola®M was within the stability standards after storage for 6 months under all conditions. The other tablet formulae of simvastatin showed changes in hardness or elution pattern even under the condition of shielded light at room temperature, indicating that care is needed in preparing one-dose packages of these formulae. Four tablet formulae of pravastatin used in this study were stable for 6 months under shielded light at room temperature. It was also found that three of the five formulae with decreasing elution velocity contained crospovidone and that the other formulae contained no crospovidone. This decrease in elution velocity appears to be due to reduction in porosity of the tablet caused by high humidity.