Application of factorial design of experiments to predict the chemical stability of ferrous fumarate and thiamine hydrochloride tablets

ABSTRACT

In this-investigation factorial design of experiment of the type N = 2 [3]was applied to predict the chemical stability of ferrous fumarate and thiamine 'hydro chloride in tablets prepared by direct and wet granulation techniques, using Span 40, stearic acid and PEG 6000 as granulating agents. The quantitative factors were the temperature, humidity and time, corresponding to the accelerated storage conditions which are 52% and 95% relative humidity at two temperature levels [25 and 42 C]. The effect of the three operating factors and their interactions on the stability of both drugs as well as the derivation of impervical, regression equations were determined. The derived regression equations have the ability to predict the chemical stability of ferrous fumarate and thiamine hydrochloride tablets at any particular conditions within the limits specified. In addition, the coefficients of the factors and their interactions were found to have negative signs, which indicated that the effect of each factor was dependent on the level of the other two factors. The obtained results revealed that, there was very good agreement between the predicted and the experimental data obtained from the classical design of the experiments, carried out under the specified storage conditions. The reaction rate constants and [90%] of ferrous fumarate and thiamine hydrochloride tablets determined from the regression equations were found to be parallel with those determined from the first order plots. These findings indicated that, with the help of factorial design of experiments it could be possible to predict the expiry date of such tablets in a short time and less cost of experimentation