Calixto Giovana, Yoshii Ana Carolina, Rocha e Silva Hilris, Stringhetti Ferreira Cury Beatriz, Chorilli Marlus
Department of Drugs and Pharmaceuticals, School of Pharmaceutical Sciences, São Paulo State University - UNESP , Araraquara, SP , Brazil.
Pharm Dev Technol. 2015 Jun;20(4):490-6. doi: 10.3109/10837450.2014.882941. Epub 2014 Feb 7.
Bioadhesiviness of polyacrylic acid polymers make them promising hydrogels to design topical drug delivery systems, allowing a close contact with biological substrate as well as an enhanced local concentration gradient, both factors that may improve the biological performance of the drugs.
Texture and bioadhesive properties of hydrogels were assessed by using texture analyzer and they were correlated with their rheological behavior and performance as drug delivery systems.
Aqueous dispersions of both polymers were prepared at 0.5%, 1.0% and 1.5% w/v. Hardness, compressibility, adhesiveness, cohesiveness, bioadhesion, continuous flow, oscillatory dynamic test and in vitro drug release were evaluated.
Rheological and texture parameters were dependent on polymer concentration and C974P polymer built the strongest structures. Both 1.5% hydrogels presented high bioadhesion values. About 50% of the metronidazole (MTZ) was sustained released from hydrogels within 2 h with an initial burst release at early stage. After, the release rates were decreased and 10% of the MTZ was released in the next 10 h. The drug release process was driven by Fickian diffusion and complex mechanism for PP and C974P hydrogels, respectively.
The set of results demonstrated that these hydrogels are promising to be used as topical controlled drug delivery system.
聚丙烯酸聚合物的生物黏附性使其成为设计局部给药系统的有前景的水凝胶，能够与生物底物紧密接触并增强局部浓度梯度，这两个因素都可能改善药物的生物学性能。
使用质构分析仪评估水凝胶的质地和生物黏附特性，并将其与流变行为及作为药物递送系统的性能相关联。
将两种聚合物的水分散体分别配制成0.5%、1.0%和1.5%（w/v）。评估硬度、压缩性、黏附性、内聚性、生物黏附性、连续流动、振荡动态测试和体外药物释放。
流变学和质地参数取决于聚合物浓度，且C974P聚合物形成的结构最强。两种1.5%的水凝胶均呈现出较高的生物黏附值。甲硝唑（MTZ）约50%在2小时内从水凝胶中持续释放，早期有初始突释。之后，释放速率降低，在接下来的10小时内释放了10%的MTZ。PP和C974P水凝胶的药物释放过程分别由菲克扩散和复杂机制驱动。
这组结果表明这些水凝胶有望用作局部控释给药系统。
