Formulation of Oral Mucoadhesive Tablets of Terbutaline Sulphate Using Some Natural Materials and In Vitro-In Vivo Evaluation

Mucoadhesive polymers that bind to the gastric mucin or epithelial cell surface are useful in drug delivery for the purpose of increasing the intimacy and duration of contact of drug with the absorbing membrane. Several synthetic polymers are in use for this purpose. Since the biodegradability of the synthetic polymers are questionable, in this investigation an oral mucoadhesive controlled delivery system has been developed for terbutaline sulphate (TS) using natural mucoadhesive materials extracted from the edible fruits like Zizyphus mauritiana (ZM) and Aegle marmelos (Linn.) Cor. (AM) that have better mucoadhesive property than synthetic polymer hydroxypropylmethylcellulose K4M (HPMC K4M). The in vitro adhesive and mucoadhesive strength of mucoadhesive materials extracted from the fruits of ZM and AM were evaluated and compared with HPMCK4M using both Share Stress and Wilhelmy Plate. Different formulations of oral mucoadhesive coated TS tablets were prepared using these natural materials and compared with tablets prepared with HPMCK4M and hardness, thickness, friability, weight variation and drug content of tablets were tested. The in vitro release of TS was studied in buffer pH 7.2 at 37°C ± 0.5°C. Tablets were orally administered to rabbits and blood plasma concentration of TS was determined using HPLC. It was found that mucoadhesive materials extracted from the fruits of ZM and AM exhibited better adhesiveness and mucoadhesiveness as compared with the HPMC- K4M. The in vitro study of TS exhibited showed greater drug release profile for tablets prepared with natural materials than synthetic polymers and confirmed with in vivo study. In vitro and in vivo correlation showed the same release profile.