Abstract
A formulation containing an antiinflammatory agent (diclofenac sodium), two inert matrices (ethylcellulose and polyvinyl chloride) and two lubricants (magnesium stearate and talc) was optimized by a double compression process
In a first stage, preliminary trials were performed in order to study the effect of lubricants added before and after precompression
An Hadamard matrix H(8) was applied to estimate the main effects of four parameters: applied force at the upper punch (UPF) during precompression, particle size range after grinding, UPF during the final compression and concentration of ethylcellulose added before the final compression
Following the Hadamard matrix, a factorial design 22 was built. The complete linear models were fitted by regression for each response reflecting the compression behaviour and dissolution kinetics
In an optimal point, the validation was carried out with the area under the dissolution curve, being the major response to be optimized
The dissolution curves were well fitted by the Weibull distribution