Vista Pharmaceuticals Ltd.

A computer program was developed to compute quadratic polynomial coefficient which is required for the determination of Piroxicam in dissolution test.By the use of Glenn's method of orthogonal polynomial coefficient irrelevant absorption due to gelatin capsules and other pharmaceutical excipients is discounted.In order to extract the quadratic polynomial coefficient the absorbance was measured at eight points equally spaced at 3 nm levels from 324 to 345 nm.The quadratic polynomial coefficient was found to bear a linear relation in the concentration range of 4 to 18 mcg. per mL. of Piroxicam.Lower values obtained by the present method indicated irrelevant absorption was corrected in the dissolution test of Piroxicam capsules.

A simple and sensitive spectrophotometric method for the estimation of Dapsone based on Schiff's base formation with 4-dimethylaminocinnamaldehyde in the presence of methanolic sulfuric acid is described.The red colored chromogen had absorption maxima at 540 nm, and obeyed Beer's law in the concentration range 0.25-2 μg/mL.Pharmaceutical excipients did not interfere with the proposed method.