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Advances in Pharmacological Sciences
Volume 2013 (2013), Article ID 192408, 11 pages
Research Article

Preparation and Evaluation of Intravaginal Ring Containing Drospirenone

1Research Center of Biomaterial and Novel Drug Delivery Systems, National Research Institute for Family Planning, No. 12 Da Hui Si Haidian District, Beijing 100081, China
2Chinese Academy of Medical Science and Peking Union Medical College, No. 9, Dongdan No. 3 Avenue, Beijing 100730, China

Received 11 September 2012; Revised 30 November 2012; Accepted 5 December 2012

Academic Editor: Abdelwahab Omri

Copyright © 2013 Ying Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In the present study, we investigated the feasibility of the vaginal administration of drospirenone silicone IVR. The in vitro release characteristics of matrix-type and reservoir-type IVR were compared under sink conditions in 21 days. At the same time, API excipients compatibility and preformulation study was performed by HPLC, IR, and DSC methods. Biocompatibility of reservoir system was evaluated by tolerability on tissue level in rats. It was found that, under strong light exposure, high temperature, and high humidity conditions, drospirenone and excipients had no significant interactions. The daily release of reservoir-type IVR was about 0.5 mg/d sustaining 21 days, which significantly decreased the burst effect compared with the matrix system. When drospirenone was modified by the PVPk30 in the reservoir system formulation, the daily release rate increased to 1.0 mg/d sustaining 21 days. The cumulative release of reservoir-type IVR was fitted to zero release equation. In addition, biocompatibility of drospirenone IVR system in this dosage is safe. It is feasibility feasibile to further developed for safe, convenient, and effective contraceptive drug delivery with reduced dosing interval.