Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt.
Pharm Dev Technol. 2011 Oct;16(5):497-510. doi: 10.3109/10837450.2010.495394. Epub 2010 Jun 16.
A suitable topical formulation of mefenamic acid was developed in order to eliminate the gastrointestinal disorders associated with its oral administration. Drug coprecipitates prepared with different polymers at various drug-to-polymer ratios improved drug solubility and dissolution compared to pure drug and physical mixtures. PVP polymers (ratio 1:4) produced the best results. Aqueous ionic cream, ointments of absorption and water soluble bases and gels of methylcellulose, carboxymethylcellulose sodium, HPMC, Carbopol® 934 and 940, and Pluronic® F127 bases containing 1-10% drug as coprecipitates of PVP polymers (1:4) were prepared. The highest drug release was achieved at 1% drug concentration from water soluble base and methylcellulose among cream/ointment and gel bases, respectively. Gels, in general yielded better release than creams/ointments. All tested medicated creams/ointments exhibited plastic flow while all gels conformed to pseudoplasticity. Most of them showed thixotropy, a desired property of topical preparations. Stability studies revealed that HPMC and methylcellulose had the smallest changes in drug content, viscosity, and pH among the formulations. Considering drug release, rheological properties, and stability, methylcellulose gel containing 1% drug as coprecipitates of PVP K90 was the best among the studied formulations, was promising for improving bioavailability of mefenamic acid and can be used in future studies.
为了消除口服甲芬那酸引起的胃肠道紊乱，开发了一种合适的局部制剂。与纯药物和物理混合物相比，用不同聚合物以不同药物-聚合物比例制备的药物共沉淀物提高了药物的溶解度和溶解速率。PVP 聚合物（比例 1:4）的效果最佳。制备了含有 1-10%药物作为 PVP 聚合物（1:4）共沉淀物的水性离子乳膏、吸收软膏、水溶性基质和甲基纤维素、羧甲基纤维素钠、HPMC、Carbopol®934 和 940 凝胶、Pluronic®F127 凝胶。从水溶性基质和甲基纤维素乳膏/软膏和凝胶基质中，以 1%药物浓度获得了最高的药物释放率。一般来说，凝胶的释放效果优于乳膏/软膏。所有测试的含药乳膏/软膏在流动时表现出塑性，而所有凝胶均符合假塑性。它们大多数表现出触变性，这是局部制剂的理想特性。稳定性研究表明，在配方中，HPMC 和甲基纤维素的药物含量、粘度和 pH 变化最小。考虑到药物释放、流变学性质和稳定性，含有 1%药物作为 PVP K90 共沉淀物的甲基纤维素凝胶是研究配方中最好的，有望提高甲芬那酸的生物利用度，可用于未来的研究。
