In the present study, an attempt was made to develop immediate-release enteric-coated time release tablets of salbutamol sulphate for the treatment of nocturnal asthma. Nocturnal asthma is an asthma phenotype marked by nighttime increases in airway inflammation, airway hyper responsiveness, and expiratory airflow limitation. The occurrence of nocturnal asthma is associated with increased morbidity and inadequate asthma control, and has an important negative impact on quality of life. Formulation of enteric-coated time release tablets with suitable lag time could address the problems associated with asthma. To achieve this goal, immediate release tablets were prepared by direct compression method using superdisintegrants that contribute to the faster disintegration of tablet and thereby improved solubility of the drug. Different disintegrants like cross caramellose sodium, crospovidone and sodium starch glycolate in different concentrations (2.5 – 7.5%w/w) were tried in order to further improve disintegration time. The formulation, which showed best disintegration and dissolution profile, was coated with ethyl cellulose as inner layer and Eudragit S100 as outer enteric-coating polymer which does not dissolve at gastric pH but dissolve at intestinal pH, releasing the drug immediately in the alkaline medium. The optimized enteric-coated formulation E6 containing 2.5%w/w of Eudragit S 100 and 30%w/w of ethyl cellulose as coating system inhibited the release of the drug in 0.1 N HCl, and whereas 99.04% of drug was released in the intestinal medium. Thus, dissolution profiles indicated that E6 tablet may be better alternative in the treatment of nocturnal asthma which overcomes the problems of conventional forms
