Two cost effective spectrophotometric methods are developed and validated for quantitative determination of paracetamol (PCT) and promethazine hydrochloride (PMZ) in tablet dosage form. Method I is based on the simultaneous equation and Method II on the absorbance ratio.The absorption maxima were found to be at 244 nm and 254 nm in distilled water for both the drugs. Beer's law is obeyed in the concentration range of 5-25 µg/ml for paracetamol and promethazine hydrochloride with correlation

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... ficient within range of 0.996-0.998. The simultaneous equation method is based on the additivity of absorbencies and the absorbance ratio method involves determination of the ratio of absorbance at 254 nm, the absorption maxima of promethazine and isoabsorptive wavelength 248 nm. The accuracy was assessed by recovery studies.