Aim: The aim of the study was to prepare matrix tablet of lithium carbonate using hydrophilic polymers such as hydroxypropyl methylcellulose (HPMC) (used in different ratio) and Eudragit S 100 to obtain sustained release characteristics to achieve prolonged therapeutic effect by continuously releasing medication over an extended period of time after administration of single dose and producing a desirable blood serum level which, in turn, lead to a decrease in the occurrence of
drug toxicity.
Methodology: The tablets were prepared by wet granulation method using different polymers such as HPMC (as release retardant), Eudragit S 100, Crospovidone, and Gum acacia in different combinations as F1 to F5. The prepared formulations were evaluated for hardness, thickness, weight variation test, content uniformity, friability, swelling index, and subjected to in vitro drug release studies. Swelling index was reported to increase with the time duration.
Results: All the formulations showed acceptable pre- and post-compression properties. Swelling behavior of sustained release matrix tablets showed increase in percent weight gain in phosphate buffer pH 6.8 due to increase in amount of hydrophilic polymer. The results obtained revealed that HPMC at a concentration of 30% in formulation F4 was able to sustain the drug release for 12–14 h.
Conclusion: Hence, combinely HPMC and Eudragit at suitable concentration can effectively be used to sustain the drug release.