New Spectrophotometric Method for Azithromycin Determination

Abstract Azithromycin (AZT), an antibiotic belonging to the family of macrolides, can be analyzed by a new spectrophotometric method based on the formation of an ion pair between this drug and an inorganic complex of (Mo(V)–thiocyanate) followed by its extraction with dichloroethane. This ion‐association complex shows an orange color and exhibits a maximum absorbance at 469 nm. The experimental conditions of the reaction were studied and optimized. The calibration graph was linear (r=0.9996) over the range 10−6 M–10−5 M of AZT. This simple and validated method has been successfully applied to the determination of azithromycin in pharmaceutical formulations with a mean relative standard deviation of 1.07% and mean recovery of 99.66%. The common excipients present in azithromycin formulations did not interfere in its determination. This new spectophotometric method has been applied successfully to illustrate the dissolution profiles of original tablets and generic compounds; hence, it could be employed in routine quality control of azithromycin in pharmaceutical dosage forms.