Department of Pharmaceutical Technology, International Medical University SDN BHD, Bukit Jalil, Kuala Lumpur, Malaysia.
Pharm Dev Technol. 2012 Jul-Aug;17(4):494-501. doi: 10.3109/10837450.2010.550622. Epub 2011 May 25.
Methyl salicylate-lactose physical mixture (1:1 and 1:1.5 ratios) was incorporated into calcium alginate beads by a coacervation method involving an ionotropic gelation/polyelectrolyte complexation approach.
This study aims to determine the influence of chitosan coating over the beads on drug entrapment efficiency (DEE) and release characteristics in artificial saliva compared to that of the uncoated beads.
Changes in formulation parameters (gelation time, concentrations of Ca(2+) and alginate) resulted in decrease in DEE of chitosan-uncoated beads (p < 0.05). This is due to the combined effects of drug leach-out from the physical mixture by Ca(2+) ions, alginate gel matrix cross-linking and free drug diffusion from chitosan-uncoated beads. However, an increment in the DEE was seen for chitosan-coated beads. A rapid drug release profile was noted for uncoated beads, but for chitosan-coated beads a sustained release profile was depicted depending upon the coating conditions. Chitosan-coated beads had reduced swelling and erosion properties and thus behaved as a physical barrier to drug release. Shifting from anomalous transport type to Fickian transport confirmed the formation of physical barrier onto chitosan-coated beads.
Calcium alginate beads could be used as a controlled-release system for methyl salicylate-lactose physical mixture.
通过凝聚方法将水杨酸甲酯-乳糖物理混合物（1:1 和 1:1.5 比例）掺入海藻酸钙珠中，涉及离子凝胶化/聚电解质络合方法。
本研究旨在确定壳聚糖涂层对人工唾液中药物包封效率（DEE）和释放特性的影响与未涂层珠相比。
制剂参数（凝胶时间、Ca(2+)和海藻酸盐浓度）的变化导致壳聚糖未涂层珠的 DEE 降低（p < 0.05）。这是由于 Ca(2+)离子从物理混合物中浸出药物、海藻酸盐凝胶基质交联以及未涂层珠中游离药物扩散的综合作用。然而，壳聚糖涂层珠的 DEE 增加。未涂层珠呈现快速药物释放曲线，但对于壳聚糖涂层珠，根据涂层条件呈现出持续释放曲线。壳聚糖涂层珠具有减少的溶胀和侵蚀特性，因此表现为药物释放的物理屏障。从异常传递类型到菲克扩散类型的转变证实了壳聚糖涂层珠上形成了物理屏障。
海藻酸钙珠可用作水杨酸甲酯-乳糖物理混合物的控释系统。
