Salbutamol Sulphate Controlled Release Hydrophilic Matrix Tablets

A B S T R A C T Salbutamol sulphate (SS), a directly acting sympathomimetic drug, is a good candidate for controlled release formulations due to its short half-life but it is challenging because of its high water solubility. The aim of this work is to design oral controlled-release matrix tablets of SS using hydrophilic polymers, and thus increasing patient compliance by reducing its frequency of administration. Tablets were prepared by direct compression technique using hydroxypropyl methylcellulose, sodium carboxymethylcellulose, guar gum and xanthan gum. The compatibility of the drug with the various used excipients was studied using differential scanning calorimetry (DSC). The effects of polymer concentration, polymer viscosity and binary mixtures of some polymers on the in vitro drug release were studied. Results of DSC confirmed drug-excipients compatibility. The different prepared tablet formulae exhibited content uniformity within the acceptable limit and showed good mechanical properties. Increasing the polymer concentration from 25% to 60%, as well as increasing HPMC viscosity resulted in significant retardation (p<0.05) of the drug release. The matrix tablets formulated using HPMC K100M and guar gum in a ratio of 1:1 succeeded to control drug release up to 80.8% in 12 h. Results of stability studies of the selected formula recommend that the formulated tablets must be stored protected from light under ambient conditions.