In-vitro Characterization of Optimized Multi-Unit Dosage Forms of Theophylline and its Solid State Characterisation

摘要

The objective of this study is to compare the drug release profile of an optimized multi-unit dose(MU) tablet consisting of rapid and slow release components, a formulated sustained released tablet and two brandsof sustained release tablet formulations in the market with a designed model. The fast release component consisted ofconventional granules while the slow release component consisted of wax granules of theophylline. The optimizedMU tablets was formed by mixing the conventional and matrix granules in ratio 1:1 and compressed. Parametersevaluated were tablet tensile strength and dissolution studies. The optimized formulation was characterized withDifferential Scanning Calorimetry and Fourier-Transform Infrared Spectroscopy. Results showed that the optimizedMU tablets gave dissolution profile that was comparable with that of the designed model. The following were thedissolution parameters of the optimized MU formulation: the maximum release (m∞) = 91%, prompt release dose(mp) = 24%, time to attain maximum release (t∞) = 12h and first order release rate constant (k) = 0.20 h-1 which iscomparable with the release data for the model. The other formulations deviated by giving mp and t∞ that were toolow compared with those of the model. There were also no drug/excipient interactions. The indication is that theprompt release dose was determined not only by the amount of the rapid release components in the MU doseformulation but also by the amount of sustained release components, attributable to the deformation of granules ofrapid components into that of slow release components during tablet formulation.