Sustained release formulations maintain a constant level plasma concentration of drug so that multiple and night dosing can be avoided. Terbutaline sulphate is a β2 stimulant drug which is having a very short half-life of less than 4 hours. It is available in sustained release ‘once a day’ formulation. This study was to formulate and evaluate microspheres of Terbutaline sulphate for sustained release preparation by solvent evaporation technique using ethyl cellulose (EC) and hydroxyl propyl methyl cellulose E 50 LV (HPMC) with different ratio.FT-IR study revealed no interaction between the drug and the excipients. The prepared microspheres were characterised for micromeritic properties, drug content, in-vitro release, particle size and shape, drug loading, encapsulation efficiency. The drug release characteristics were determined for the prepared microspheres in phosphate buffer pH 6.8 dissolution media. The rate of drug …show more content…
The basic role of sustained release drug delivery system is to achieve a steady state drug in blood for the extended period of time. The design of proper dosage regimens is an important element in accomplishing this goal. In case of injectable dosage forms, this period may vary from day to months. In the case of oral administrated dosage forms, this period is measured in hours and critically depends on the residence time of the dosage form in the gastrointestinal tract. Products of this type have been formulated for oral injectables and topical use and inserts for placement in the body cavities[2]. Sustained release systems are suitable for diseases that have marked diurnal rhythms, where the therapeutic concentrations should vary during the day. Drug levels should be highest when the symptoms are most severe[3]. Criteria to be met by drug proposed to be formulated in sustained release dosage forms[4] 1) Desirable half