In the present research work an attempt has been made to optimize, formulate and evaluate pH sensitive multiparticulate system of salbutamol sulphate to achieve chronotherapeutic drug delivery for nocturnal asthma. The whole research work performed stepwise such as preformulation studies, development of core microparticle and development of coated microparticle, In the preformulation studies salbutamol sulphate was characterized physiochemical properties such as melting point, solubility, UV and FTIR. UV spectrophotometric method was established for quantitative estimation of drugs in the...