Prabhu Prabhakara, Dubey Akhilesh, Parth Vinod, Ghate Vivek
Department of Pharmaceutics, Shree Devi College of Pharmacy, Mangalore, Karnataka, India.
Int J Pharm Investig. 2015 Oct-Dec;5(4):214-25. doi: 10.4103/2230-973X.167684.
Hydrogel is a cross-linked network of polymers. Water penetrates these network causing swelling and giving the hydrogel a soft and rubbery consistency and there by maintaining the integrity of the membrane. Due to the drawback of conventional therapy for ocular delivery, hydrogel membranes containing the combination of gentamicin (GT) sulfate and dexamethasone (DX) were formulated for the treatment of conjunctivitis. The objective of this study was to formulate and evaluate the hydrogel membranes containing the combination of GT and DX for the treatment of conjunctivitis.
In the present investigation, hydrogel membranes were prepared by using polymers such as gelatin, polyvinyl alcohol, and chitosan, which were cross-linked using physical/chemical methods.
The cross-linking of the membranes was confirmed by Fourier transform infra-red studies. The pH of the membranes ranged from 7.19 to 7.45 and drug content ranged from 69.82% to 89.19%. The hydrogels showed a considerably good swelling ratio ranging from 22.5% to 365.56%. The in vitro drug release study showed that there was a slow and sustained release of the drug from the membranes which were sufficiently cross-linked and followed zero order release. In vivo studies showed that the severity of conjunctivitis was remarkably lowered at day 3 with hydrogel membrane compared to marketed eye drops. Results of unpaired t-test of significance between two groups indicated that the hydrogel membrane showed a better response in the treatment of conjunctivitis compared to the marketed products. Stability studies proved that the formulations could be stable when stored at room temperature.
Results of the study indicated that it is possible to develop a safe and physiologically effective hydrogels which are patient compliant.
水凝胶是聚合物的交联网络。水渗透到这些网络中导致膨胀，使水凝胶具有柔软且类似橡胶的稠度，从而维持膜的完整性。由于眼部给药传统疗法的缺点，配制了含有硫酸庆大霉素（GT）和地塞米松（DX）组合的水凝胶膜用于治疗结膜炎。本研究的目的是配制并评估含有GT和DX组合的水凝胶膜用于治疗结膜炎。
在本研究中，使用明胶、聚乙烯醇和壳聚糖等聚合物制备水凝胶膜，并采用物理/化学方法进行交联。
通过傅里叶变换红外研究证实了膜的交联。膜的pH值范围为7.19至7.45，药物含量范围为69.82%至89.19%。水凝胶显示出相当好的溶胀率，范围为22.5%至365.56%。体外药物释放研究表明，药物从充分交联的膜中缓慢且持续释放，并遵循零级释放。体内研究表明，与市售眼药水相比，水凝胶膜在第3天时可显著降低结膜炎的严重程度。两组之间的不成对t检验显著性结果表明，与市售产品相比，水凝胶膜在治疗结膜炎方面显示出更好的效果。稳定性研究证明，制剂在室温下储存时可以保持稳定。
研究结果表明，有可能开发出一种安全且生理有效的、患者依从性好的水凝胶。
