ABSTRACT
Objective: To investigate the application characteristics of excipient copovidone in co-grinding process and the feasibility of co-grinding products for improving the dissolution of curcumin, using curcumin as a model drug in vitro. Methods: The prepared products were obtained by curcumin and various proportions (0%, 1%, 3%) of copovidone in co-grinding process, which were characterized by laser particle size analyzer, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X-ray powder diffraction (XRPD). The in vitro dissolution of milled products was evaluated in two media, and their accelerated stability was investigated. Results: In comparison with pure curcumin, the particle size of milled products decreased with the lower crystallinity by XRPD analysis, but the hygroscopicity and DSC thermograms showed no significant difference. Moreover, compared with pure curcumin, the products exhibited significant improvement of in vitro dissolution. Also, there was no significant difference in the dissolution behavior of products placed under the accelerated conditions (40 ℃, RH 75%) for three months, indicating their good stability. Conclusion: As a new excipient, copovidone could effectively enhance the dissolution of curcumin via co- grinding process. This study provided a feasible strategy for improving the solubility and even oral bioavailability of poorly soluble drugs.
ABSTRACT
OBJECTIVE: To improve the dissolution rate of nitrendipine in vitro using co-grinding method.METHODS: Single-factor test was adopted to detect effect of phases of co-grinding,category of excipients (MCC,PVPk30,HPC,HPMC),time (0,10,20,30,40,50,60 min) of co-grinding and ratio of principal component to excipients (1 ∶ 1,1 ∶ 2,1 ∶ 3,1 ∶ 4,1 ∶ 5,1 ∶ 6,1 ∶ 7,1 ∶ 8,1 ∶ 9) on in vitro dissolution of nitrendipine power and tablet.RESULTS: The condition of co-grinding method was as follows: dual co-grinding phase,HPC or MCC as excipients,co-grinding time of 40 min,ratio of principal component to excipients was 1 ∶ 4.Accumulative dissolution rate of nitrendipine powder was more than 80% within 10 min and that of nitrendipine tablet was more than 80% within 40 min.CONCLUSION: Co-grinding method can improve the dissolution rate of poorly water-soluble nitrendipine in vitro under suitable condition.