Purpose: Although different brands or unbranded chlorpromazine tablets from multiple sources are available in Nigeria today, they must all contain the same active principle and satisfy the standards of quality, efficacy and safety. This study is designed to check for possible faking and adulteration of chlorpromazine tablets and also establish the possibility of inter-brand substitution based on drug content (chemical equivalence).

Method: The determination of the chlorpromazine hydrochloride content was carried using non-aqueous titrimetric and spectrophotometric methods. Glacial acetic acid and acetone were used as the non-aqueous solvent and equivalence points were determined using visual indicators and potentiometer.

Results: The results obtained showed that all the brands analyzed met the specification of the British Pharmacopoeia and so contain acceptable amounts of chlorpromazine drug content thus enabling possible brand substitution.

Statistical comparison showed no significant difference between the results obtained by determining end-point using visual indicators and the potentiometer.

Conclusion: The use of the visual indicator method is recommended for fast and accurate routine laboratory analytical work especially in developing nations.

Keywords: Chlorpromazine, non-aqueous titration, spectrophotometric determination, potentiometry.