Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina.
AAPS PharmSciTech. 2013 Jun;14(2):727-35. doi: 10.1208/s12249-013-9958-9. Epub 2013 Apr 19.
β-cyclodextrin (βCD) and methyl-β-cyclodextrin (MβCD) complexes with sulfamethazine (SMT) were prepared and characterized by different experimental techniques, and the effects of βCD and MβCD on drug solubility were assessed via phase-solubility analysis. The phase-solubility diagram for the drug showed an increase in water solubility, with the following affinity constants calculated: 40.4±0.4 (pH 2.0) and 29.4±0.4 (pH 8.0) M(-1) with βCD and 56±1 (water), 39±3 (pH 2.0) and 39±5 (pH 8.0) M(-1) with MβCD. According to (1)H NMR and 2D NMR spectroscopy, the complexation mode involved the aromatic ring of SMT included in the MβCD cavity. The complexes obtained in solid state by freeze drying were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and thermal analysis. The amorphous complexes obtained in this study may be useful in the preparation of pharmaceutical dosage forms of SMT.
β-环糊精(βCD)和甲基-β-环糊精(MβCD)与磺胺间甲氧嘧啶(SMT)形成的复合物,通过不同的实验技术进行了制备和表征,并通过相溶解度分析评估了βCD 和 MβCD 对药物溶解度的影响。药物的相溶解度图显示出水溶性增加,计算得到的亲和常数如下:在 pH 2.0 时为 40.4±0.4 M(-1),在 pH 8.0 时为 29.4±0.4 M(-1),与βCD 形成复合物;在水中为 56±1 M(-1),在 pH 2.0 时为 39±3 M(-1),在 pH 8.0 时为 39±5 M(-1),与 MβCD 形成复合物。根据(1)H NMR 和 2D NMR 光谱,包合模式涉及 SMT 的芳环被包含在 MβCD 空腔内。通过冷冻干燥获得的固体复合物通过傅里叶变换红外光谱、扫描电子显微镜和热分析进行了表征。本研究中获得的无定形复合物可能有助于制备 SMT 的药物剂型。