Abstract The aim of the present exploration was to develop novel pH-sensitive cross-linked Gelatin/Polyvinyl pyrrolidone hydrogels using different ratios of both the polymers and to investigate the effect of polymers and degree of crosslinking on dynamic, equilibrium swelling and invitro release pattern of the model drug (captopril). Grafting polymerization technique was used for the preparation of these hydrogels using glutaraldehyde as crosslinking agent. These polymeric materials were then used as model systems to envisage various important characterizations like FTIR (Fourier transform infrared spectroscopy), XRD (X-ray diffraction) and scanning electron microscopy (SEM). Phosphate buffers of pH 1.2, 6.5 and 7.5 were used for swelling and invitro drug release profile investigation. Different parameters like swelling analysis, porosity, sol-gel analysis, average molecular weight between crosslinks (Mc), solvent interaction parameter (χ), volume fraction of polymer (V2,s) and diffusion coefficient that affects the drug release behavior were also determined. Higher swelling and release was observed at lower pH values. FTIR spectra showed interaction between gelatin and polyvinyl pyrrolidone and successful formation of cross-linked structure. Pulsatile drug release study showed the controlled delivery of model drug. The release of drug occurred through non-fickian diffusion or anomalous mechanism. Aforementioned characterizations reveal successful formation of copolymer. pH sensitive swelling ability and drug release behavior suggest that the rate of polymer chain relaxation and the rate of drug diffusion from these hydrogels are comparable which also predicts their possible use for site specific captopril delivery.

中文翻译：

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用于控制递送抗高血压药物的生物相容性水凝胶：开发、表征和体外评估

摘要 本研究的目的是开发新型 pH 敏感交联明胶/聚乙烯吡咯烷酮水凝胶，使用不同比例的聚合物，并研究聚合物和交联度对水凝胶的动态、平衡溶胀和体外释放模式的影响。模型药物（卡托普利）。使用戊二醛作为交联剂，接枝聚合技术用于制备这些水凝胶。然后将这些聚合物材料用作模型系统，以设想各种重要的表征，如 FTIR（傅里叶变换红外光谱）、XRD（X 射线衍射）和扫描电子显微镜（SEM）。pH 1.2、6.5 和 7.5 的磷酸盐缓冲液用于溶胀和体外药物释放曲线研究。不同的参数，如溶胀分析、孔隙率、还测定了溶胶-凝胶分析、交联之间的平均分子量 (Mc)、溶剂相互作用参数 (χ)、聚合物的体积分数 (V2,s) 和影响药物释放行为的扩散系数。在较低的 pH 值下观察到较高的溶胀和释放。FTIR 光谱显示明胶和聚乙烯吡咯烷酮之间存在相互作用并成功形成交联结构。脉冲式药物释放研究显示模型药物的受控递送。药物的释放是通过非菲克扩散或异常机制发生的。上述表征揭示了共聚物的成功形成。