An attempt was made to design matrix tablet of diclofenac sodium by using various grades of hydroxypropyl methyl cellulose (HPMC E50, E15 and E300LV). The effect of hydrophilic polymers was studied on release characteristics of the diclofenac matrix tablet. Dicalcium phosphate and magnesium stearate were used as an excipients. Tablets were prepared by direct compression method. The in vitro dissolution test carried out for 12 hrs using USP dissolution apparatus II at 50 rpm in 900ml phosphate buffer pH 6.8. Statistically significant difference was found among the drug release profile from different matrices. The tablet evaluation parameters of hardness, friability, thickness, content uniformity were founded within the limit. At a fixed polymer level, drug release from the higher viscosity grades E50 was slower as compared to the lower viscosity grades (E300LV and E15). Tablet prepared with HPMC E50 is more release retardant. As the drug to polymer ratio increased drug release decreased. The dissolution study revealed that maximum retardation of the drug was obtained by highest viscosity grade HPMC at higher concentrations. The release of the model drug from these HPMC matrix tablets was prolonged.
Key words: Diclofenac sodium, Hydrophilic matrix, Hydroxypropylmethylcellulose, Sustained release.
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