Sanz Taberner T, Martín-Villodre A, Pla-Delfina J M, Herráez José Vicente
Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Valencia, 46100, Valencia, Burjassot, Spain
Int J Pharm. 2002 Feb 21;233(1-2):43-50. doi: 10.1016/s0378-5173(01)00937-1.
A study is made of the polymerization process of polyacrylic acid, commercially known as Carbopol 971 NF, assessing its consistency as a function of the degree of neutralization at pH values from 3 to 12, approximately. Percentage concentrations ranging from 0.1 to 1.4% (w/w) were studied. The gels obtained were non-Newtonian, and pseudoplastic. As concentration and pH rise, the consistency of the gels increase to a maximum, which appears between pH 6 and 8, allowing their use as vehicles in bioadhesive formulations for mucosal application. Over the increasing viscosity interval, functions were obtained to indicate the consistency of the gel as a function of pH and concentration. Since the correlation between the theoretical and experimental results is excellent, the equation found can be used to theoretically calculate the working concentration and pH required to secure the necessary consistency for a given vehicle. The addition of soluble polyvinylpyrrolidone (PVP), and cross-linked PVP (PVPP) does not substantially modify the rheological behavior of the gels, thus permitting their addition to usual vehicles.
对商品名为卡波姆971 NF的聚丙烯酸聚合过程进行了研究，评估了其在pH值约为3至12时作为中和度函数的稠度。研究了0.1%至1.4%（w/w）的百分比浓度。所获得的凝胶为非牛顿型且呈假塑性。随着浓度和pH值升高，凝胶的稠度增加至最大值，该最大值出现在pH 6至8之间，这使得它们可作为用于黏膜应用的生物黏附制剂中的载体。在粘度增加区间，获得了一些函数以表明凝胶稠度作为pH值和浓度的函数。由于理论结果与实验结果之间的相关性极佳，所发现的方程可用于从理论上计算获得给定载体所需稠度所需的工作浓度和pH值。添加可溶性聚乙烯吡咯烷酮（PVP）和交联PVP（PVPP）不会显著改变凝胶的流变行为，因此允许将它们添加到常用载体中。
