Department of Pharmaceutical Technology, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, 73000, Thailand.
AAPS PharmSciTech. 2010 Sep;11(3):1315-9. doi: 10.1208/s12249-010-9513-x. Epub 2010 Aug 21.
Drug-loaded calcium pectinate gel (CaPG) beads were prepared by either mixing, absorption, or swelling method. The effects of drug loading method as well as the drug loading factors (i.e., drug concentration, soaking time in drug solution, type of solvent) on drug content and drug release were investigated. The amount of drug uptake (i.e., drug content) into CaPG beads increased as the initial drug concentration increased and varied depending on the loading method. The in vitro release studies in 0.1 N hydrochloric acid (HCl) and pH 6.8 buffer indicated that the drug loading method affected drug release and release parameter, time for 50% of drug release (T(50)). The mixing method provided a faster drug release and lower T(50) than the absorption method and swelling method, respectively. This is probably due to higher drug content in CaPG beads. The increased concentration of drug in soaking solution and soaking time resulted in higher drug content and thus faster drug release (lower in T(50) values). When using 0.1 N HCl as solvent for soaking instead of water, the drug release was slower owing to the increase in molecular tortuosity of CaPG beads. The drug release was also affected by pH of the release medium in which drug release in 0.1 N HCl was faster than in pH 6.8 buffer.
载药海藻酸钙凝胶（CaPG）珠粒通过混合、吸附或溶胀法制备。考察了载药方法以及载药因素（即药物浓度、药物溶液浸泡时间、溶剂类型）对药物含量和药物释放的影响。药物在 CaPG 珠粒中的摄取量（即药物含量）随初始药物浓度的增加而增加，并取决于载药方法。在 0.1N 盐酸（HCl）和 pH6.8 缓冲液中的体外释放研究表明，载药方法影响药物释放和释放参数，即 50%药物释放的时间（T（50））。与吸附法和溶胀法相比，混合法提供了更快的药物释放和更低的 T（50）。这可能是由于 CaPG 珠粒中药物含量较高。浸泡溶液中药物浓度和浸泡时间的增加导致药物含量增加，从而导致药物释放更快（T（50）值更低）。当使用 0.1N HCl 作为浸泡溶剂而不是水时，由于 CaPG 珠粒的分子曲折度增加，药物释放会变慢。药物释放还受到释放介质 pH 值的影响，在 0.1N HCl 中的药物释放速度快于 pH6.8 缓冲液。
