Use of factorial design for the evaluation of the chemical stability of aspirin tablets

ABSTRACT

A factorial experimental design of type N = 2 3 was applied to predict the chemical stability of aspirin tablets directly compressed with sucrose-based vehicles [DiPac, Nu-Tab and Sugartab] and Avicel under 4 sets of storage conditions, 25% and 95% RH at two temperature levels [20C and 45C]. Tablets prepared by wet granulation technique were also employed for comparison. The quantitative factors were the temperature, relative humidity and time. The type of the vehicle used is only a qualitative factor. Tablets prepared with Avicel and those prepared by wet granulation technique gave complete measurable stability data under the selected storage conditions. The validity of the derived regression equations was verified by the experimental data of the classical design of experiments and the t50 values. Good agreement between the experimental and predicted data was obtained. Regression equations for the stability of tablets prepared with sucrose-based vehicles were not available due to their deformation under the selected storage conditions. The results of this investigation indicated that factorial design can have utility in predicting the chemical stability and expiry date of tablets in a short time and with less cost of experimentation