Formulation and in vitro-in vivo Evaluation of Theophyline and Salbutamol Sulphate Sustained Release Tablets

The objective of this study was to formulate and evaluate a matrix system for sustained and simultaneous delivery of two anti-asthmatic drugs Salbutamol sulphate and Theophylline which is often indicated for the management of asthma, their frequent dosing may reduce compliance, thus making prolonged release formulation necessary.

The matrix tablets were prepared by wet granulation method using hydroxypropyl methylcellulose (HPMC K15M, K4M; HPC and Carbapol 934P) in various percentages. The granules showed satisfactory flow properties and compressibility. All the five tablet formulations showed acceptable pharmacotechnical properties and complied with the in-house specifications for tested parameters. The release rate could efficiently be modified by varying the matrix forming polymer, the use of polymer blends and the addition of water soluble or water insoluble fillers (such as dicalcium phosphate, lactose or mannitol). The tablets swelled and eroded upon contact with release medium. Fitting the in-vitro drug release data to Korsmeyer equation indicated that diffusion along with erosion could be the mechanism of drug release.