Manufacturing and Characterization of Long-Acting Levonorgestrel Intrauterine Systems

In this study, a twin-syringe method with a customized mold was developed to manufacture hollow cylindrical polydimethylsiloxane (PDMS)-based levonorgestrel intrauterine systems (LNG-IUSs). Different mold materials, curing temperatures and times were screened to fabricate PDMS-drug reservoirs with good quality characteristics (easy demolding, good appearance and appropriate physicochemical characteristics). The prepared PDMS-drug reservoirs were covered with the release rate controlling membrane to fabricate the LNG-IUSs. Physicochemical characterization (drug content and content uniformity, powder X-Ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FTIR) of the PDMS-drug reservoirs with different drug loadings (10%, 25% and 50% w/w) was conducted. Real-time in vitro drug release testing of LNG-IUSs with different drug loading was performed in normal saline (0.9% w/v NaCl) at 37°C using a water bath shaker rotating at 100 rpm. The prepared PDMS-drug reservoirs demonstrated good and reproducible quality characteristics including appearance (smooth surfaces), targeted drug loading and good drug content uniformity in the PDMS matrix. The PXRD showed that the crystallinity of the API was maintained inside the PDMS matrix. DSC, TGA and FTIR confirmed the structure of the drug and the PDMS, indicating no interaction between the drug and the PDMS matrix in the prepared LNG-IUSs. Real-time i...
Source: International Journal of Pharmaceutics - Category: Drugs & Pharmacology Source Type: research