Circular dichroism spectroscopy: An efficient approach for the quantitation of ampicillin in presence of cloxacillin
Nafisur Rahman, Sumaiya Khan
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Ampicillin exhibited a negative and a positive cotton effects on the circular dichroism (CD) spectra in the wavelength range of 200–280 nm. Cloxacillin showed a positive cotton band peaking at 228 nm. Three sensitive, precise and accurate CD spectroscopic methods have been developed for the determination of ampicillin and cloxacillin. Method A was used for the determination of ampicillin in presence of cloxacillin by measuring ellipticity at 206 nm. Method B and C were employed to determine ampicillin and cloxacillin based on evaluation of ellipticity at 233 nm and 228 nm, respectively. Methods A, B and C showed linearity in the concentration range of 10–40 μg mL− 1, 5–40 μg mL− 1ampicillin and 10–80 μg mL− 1 cloxacillin, respectively. The method A was successfully applied to the determination of ampicillin in commercial dosage forms containing equivalent amount of cloxacillin.
Circular dichroism, Pharmaceutical