A novel directly compressible co-processed excipient, based-on rice starch for extended-release of tablets

Abstract

The development of a direct compression excipient with extended-release property is crucial for improving tablet manufacturing and drug delivery. This research focuses on developing a novel co-processed excipient composed of rice starch (RS), methylcellulose (MC), and colloidal silicon dioxide (CSD) using a wet granulation technique. The ratios of RS: MC (1.66:1–1:3) and CSD concentrations (1.0 – 8.26 %) on the properties of co-processed material were evaluated. The RS co-processed with MC and CS (RMSs) formed agglomerate particles (199 – 294 μm of average particle size) with irregular shapes and rough surfaces due to the wet granulation technique. FT-IR spectroscopy confirmed that there was no change in the chemical structure during co-processing, while the amorphous characteristic of MC considerably decreased the crystallinity of the RMSs. The increase in the particle size and the bulk density of the RMSs improved material flowability (17 – 18° for angle of repose) and facilitated particle rearrangement during die filling. RS plasticity promoted material compressibility, while the brittleness of CSD contributed to the increased tablet tensile strength. The elastic recovery of RMSs relied on the ratio of RS, which facilitated permanent bonding, whereas incorporating CSD reduced the lubricant sensitivity of material. The co-processing with MC significantly improved material swellability and effectively maintained the polymer matrix for a long period in media with pH 1.2, 4.5, and 7.5. The in vitro release study confirmed the ability of RMSs to prolong drug release from the matrix tablets, where the cumulative drug release of RMS-2 tablets met the specification and conformed with Higuchi model. Among the RMSs, RMS-2 (RS co-processed with 48.7 % MC and 2.68 % CSD) exhibited the optimal ratio of co-processing, as it demonstrated more favorable compression behavior and extended-release property than other RMSs. These findings indicated that RMSs could potentially be used as a direct compression excipient with extended-release properties.