Development of a Tamsulosin Hydrochloride Controlled-Release Capsule Consisting of Two Different Coated Pellets

Development of arsenic trioxide sustained-release pellets for reducing toxicity and improving compliance

Arsenic trioxide (ATO) is first-line drug for acute promyelocytic leukemia. Clinically, the continuously slow intravenous infusion is adopted to maintain effective blood concentration and reduce toxic effects, but it causes poor patient' compliance for a considerable infusion period. To overcome these disadvantages, we developed an oral ATO sustained-release preparation which was constructed via the ATO core pellets prepared by extrusion spheronization and followed by a coating membrane by fluid-bed technology. The prepared coated pellets displayed a round surface and uniform particle size. All in vitro release profiles of ATO pellets in different pH media and rotation speeds had no statistical difference. Importantly, the coated pellets can release completely in 12 h without obvious burst release. There was no distinct change in appearance and release behaviors in stability experiments. In vivo pharmacokinetics was studied by one-time intragastric administration of rats. Compared with free drug, the AUC_0-∞ of the ATO coated pellets was 2.3-fold higher, indicating the oral bioavailability was significantly increased. C_max decreased by about a half and T_max extended about 15 h. In particularly, the ATO level at 96 h only decreased about 20% of C_max , suggesting that the ATO sustained-release preparation could not only decrease the peak concentration, but also maintain a relatively constant blood concentration for a long period. Further, the in vivo absorption could be well predicted by in vitro release experiments. Therefore, the ATO sustained-release preparation formulated by the mature preparation technology, possessing satisfactory stability and improving bioavailability, had great application potentials for industrialization.

Preparation and stability investigation of tamsulosin hydrochloride sustained release pellets containing acrylic resin polymers with two different techniques

The objective of this study was to prepare tamsulosin hydrochloride-sustained release (TSH-SR) pellets which showed good release stability with frame-controlled method. TSH was added to Eudragit^®NE30D and Eudragit^®L30D-55 polymers to form drug-loaded inner core. Afterwards, enteric Eudragit^®L30D-55 polymer was modified on the surface of it to the final product. Dissolution studies showed that TSH-SR pellets were more stable during the coating process, different curing temperatures and storage conditions compared with TSH pellets produced by film-controlled technique. Appearances and glass transition temperatures (Tgs) of free films and surface morphologies observed by scanning electron microscopy (SEM) of blank sustained release pellets prepared by different ratios of Eudragit^®NE30D and Eudragit^®L30D-55 further indicated that temperature and relative humidity (RH) were the key factors when Eudragit^®NE30D blended with Eudragit^®L30D-55 were applied to sustained/controlled release preparations. In addition, SEM identified the surface morphologies of TSH-SR pellets before and after dissolution, which showed intact surface structure and great correlation with release curve respectively.