Pectin-Hydroxypropylmethylcellulose Drug Delivery System for Colon Targeting
Design and in vitro evaluationMurat Turkoglu a , Sevgi Takka b , Habip Baran a , and Adel Sakr b Marmara University, Faculty of Pharmacy, Department of Pharmaceutical Technology a , Haydarpasa-Istanbul (Turkey), and University of Cincinnati, College of Pharmacy, Industrial Pharmcy Program b , Cincinnati, Ohio (USA)
Pectin-Hydroxypropylmethylcellulose (HPMC) matrix tablets were prepared and evaluated of their dissolution/ erosion properties to assess their colon targeting possibility based on a gastrointestinal transit time concept. Dosage forms were tested in water and also separately in 0.1 N HCl and pH 6.8 buffer systems. HPMCs of three different molecular weights were incorporated as 25 % into a pectin USP matrix in addition to pure pectin tablets. The effect of a pectin-degrading enzyme (Pectinex 3XL) on dissolution rate was also studied. It was found that dissolution/erosion rates were faster in water than in buffer solutions. The t50 values were 3, 3.4, 5.0, and 6.0 h in water and 4.6, 5.3, 9.7, and 11.7 h in a buffer system dependent on the viscosity grade of HPMC. Addition of 25 % HPMC improved the mechanical properties of pectin matrix. Pectinex 3XL accelerated the degradation of pectin tablets as well as HPMC content of matrix. Pectin-HPMC system is recommended as protective wall layers to protect and carry protein drugs to the colon for targeting.
Key words Colon targeting Â· Drug targeting Â· Hydroxypropylmethylcellulose Â· Pectin Â· Pectinase Â· Tablets, dissolution, erosion
Â© ECV- Editio Cantor Verlag (Germany) 1999
pharmind 1999, Nr. 7, Seite 662