ABSTRACT
Sintering is a process of thermally converting loose fine particles into a solid coherent mass by heating without fully melting the particles to the point of melting. One of the most convenient approaches to the preparation of controlled release dosage forms to improve patient compliance is the formulation of matrices. The aim was to investigate the effects of different sintering temperatures and time on the physicochemical and in-vitro dissolution profiles on controlled release matrix tablets formulations of diclofenac prepared using 10% w/w mucuna sloanei gum as a binder. This study investigation was carried out by first extracting mucuna sloanei gum by ethanol precipitation after de-fattening the pulverized seeds with n-hexane. A non-aqueous wet granulation process using mucuna sloanei gum as hydrophilic matrix former was used to formulate the diclofenac granules which was further evaluated for micrometric properties and then compressed into tablets using a lubricated single punch tableting machine (type 3 Manesty machine UK) fitted with a concave punch and die set at a compression pressure of 28 arbitrary units on the load scale. The prepared diclofenac matrix tablets were divided into two batches. The first batch was left unsintered serving as control while the second batch was subjected to thermal sintering at 50°c and 60°c in a digital hot air oven for 1, 3, and 5 hours respectively. The different batches were put through both official and unofficial testing including those for hardness, tablets thickness and diameter, friability, uniformity of weight and content and also in-vitro dissolution profile. From this study, the hardness of tablet formulations increased with sintering time and temperature. For tablets that were not sintered, the mean hardness value was 8.02 ±0.15 kgf while for those sintered at 50°c for 1, 3, and 5 hours, the mean hardness values were 8.35 ±0.30 kgf, 8.98 ±0.15 kgf and 9.88 ±0.42 kgf respectively. For those sintered at 60°c for 1, 3, and 5 hours, the mean hardness values were 9.67 ±0.54 kgf, 10.22 ±0.39 kgf and 11.58 ±0.15 kgf respectively indicating a significant increase in hardness with increase sintering temperature and time. The percentage friability was observed to be affected by sintering temperature and time as percentage friability of the formulated tablets decreased with increase in sintering time and temperature. The mean friability of the unsintered tablets was 1.9 ±0.07%, whereas the mean friability of the tablets sintered at 50°c for 1, 3, 5 hours were 1.51 ±0.09%, 1.11 ±0.05 % and 0.84 ±0.08% respectively, while the mean friability of tablets sintered at 60°c for 1, 3, and 5 hours were 1.01 ±0.09%, 0.89 ±0.05%, and 0.56 ±0.07% respectively. 93.5% was found to be the greatest drug content release for unsintered tablets at the 6th hour of dissolution, while, 94.2% and 92.8% drug release contents were observed for tablets sintered at 50°c for 3 and 5 hours respectively after 10 hours. 93.5%, 92.8% and 91.3% drug release contents were observed for tablets sintered at 60°c for 1, 3, and 5 hours respectively after 10hours also. The total amount of medication released was 98.73% after 12hours. This study demonstrated that a controlled release diclofenac matrix tablet that was effectively formulated using mucuna sloanei gum at 10% w/w as the matrix polymer and thermally sintered may have its contents released up to 10hours and its level of release is a function of the sintering temperature and time. The medication was released mostly by diffusion control.
