Alternative approaches in formulating floating hollow tablets sublimation technique; a platform tailored drug release profile.

The aim of this study was to formulate floating hollow tablets of salbutamol sulphate with a platform tailored drug release profile to attain a controllable drug release. Eight formulations (F1-F8) were prepared using sublimation technique. L-menthol was directly compressed as sublimable core followed by compression coating of hydroxypropylmethyl cellulose (HPMC-K15M) or polyethylene oxide (PEO-WSR301) as release retarding polymer coat. Tablets were then subjected to heat to allow sublimation of the core. The effect of polymer type and that of different drug coat/core distribution on swelling and drug release profile was studied. FTIR and DSC revealed the absence of any drug-excipients interaction. Tablets showed a hollow morphology, resulting in low density tablets that floated for over 24 hours without lag time. Moreover, different drug coat/core distribution resulted in controllable release profiles. Based on these results, an optimum drug release behavior was recorded for HPMC-based hollow tablets consisting of 2:1 drug coat/core distribution ratio (F4), revealing a zero order drug release for over 14 hours. Furthermore, F4 showed no changes in drug content, floating properties and drug release profile upon exposure to accelerated stability conditions.