In the present study sustained release matrix tablets of Theophylline were prepared by direct compression method using different grades and ratios of hydroxy propyl methyl cellulose in presence of ethyl cellulose to examine their influence on tablet properties and drug release profile. Theophylline is used to treat chronic obstructive pulmonary disease (COPD) and asthma. The drug has a narrow therapeutic index and short half life (8 hours) which requires regular monitoring of serum theophylline concentration. Sustained delivery of the drug could reduce the adverse effects such as sinus tachycardia, nausea, tremor, indigestion etc. and improve the patient compliance. The formulated tablets were evaluated by measurement of hardness, friability, content uniformity, weight variation and drug release pattern. All the tablets met the pharmacopoeial requirements for physical tests. It was found that high viscosity grade hydroxy propyl methyl cellulose with ethyl cellulose shows a good retardation effect over drug release. Mathematical analysis of release kinetics indicates a near approximate fickian release character for most of the designed formulations. Invitro release studies showed that formulations containing hydroxy propyl methyl cellulose grade K15M sustain the drug release than formulations with hydroxyprpyl methyl cellulose 5cps.
