Spectrophotometric Method for Degradation Study of Cefixime Trihydrate

Spectrophotometric method for degradation study of cefixime trihydrate was described. The ultra violet spectrum of both acidic and basic degraded product was found to substantial difference from pure drug. The extent of degradation can be calculated by comparing the decrease in absorbance at selective wavelength. The solution which was totally degraded in NaOH did not show any absorbance at 287nm in zero order spectrums. So the decrease in absorbance at 287nm was measure of extent of degradation in NaOH. The percentage degradation for each interval was calculated by comparing the decrease in absorbance with untreated drug solution. In case of acidic degradation there was some interference at 287nm. In first order derivative there was substantial decrease in absorbance at 303nm. So the 303nm was selected for calculation of extent of degradation in acidic condition. The 98.52% of drug is degraded in 0.5hr if heated with 0.1N sodium hydroxide at 800c. In 0.01N sodium hydroxide it is somewhat stable and only 54.25% of drug is degraded in 8hr at 800c.The degradation is somewhat slower in acidic conditions as 28.08% of drug is degraded if heated with 0.1N hydrochloric acid at 800c for 7hr. The 67.42% degradation observed in 1N hydrochloric acid at 800c after 7hr. The relative standard deviation (RSD) of both alkaline and acidic degradation was found to be less than 2% which indicate that method is reproducible. The LOD and LOQ for cefixime was found to be 0.028, 0.039 and 0.092, 0.128 μg ml-1 at 287nm and 303nm respectively indicates the method is sensitive.