Measurement of chloramphenicol in pharmaceutical preparations using trifluoperazine hydrochloride as an organic reagent based on spectrophotometry.

Background: A spectrophotometric method has been developed for the measurement of trace amounts of chloramphenicol. Methods: This technique is based on the reduction of a nitro group to an amino group and oxidante coupling between drug and reagent, followed by a reaction in the presence of trifluoperazine hydrochloride and potassium iodate, resulting in the formation of a pigment. Results: This pigment exhibits maximum absorption at a wavelength of 525 nm, demonstrating high sensitivity, with a molar absorptivity coefficient of 9.7585 × 103 L·mol-1·cm-1 and a Sandell sensitivity index of 3.311 × 10-2 µg/cm-2. The method adheres to Beer’s law within a concentration range of 2 to 30 ppm, with a relative error ranging from -3.6% to +0.69%, and a standard deviation that varies from ±0.628% to ±0.113% depending on the concentration level. Conclusion: This method has been effectively utilized for the determination of chloramphenicol in pharmaceutical formulations, including ophthalmic solutions.