Development and Validation of Derivative Spectroscopic Method for Simultaneous Estimation of Cefixime Trihydrate and Azithromycin Dihydrate in Combined Dosage Form

A novel, simple, accurate, sensitive, reproducible, economical spectroscopic method was developed and validated for the determination of Azithromycin dihydrate and Cefixime trihydrate in combined dosage form. Second order derivative spectroscopy method is adopted to eliminate spectral interference. The method obeys Beer’s Law in concentration ranges of 10-40 ppm for Cefixime trihydrate and 25-100 ppm of Azithromycin dihydrate. The method was validated for linearity, accuracy and precision as per ICH guidelines. The zero crossing point for Azithromycin dihydrate and Cefixime trihydrate was 326.4 nm and 226.8 nm, respectively in water. The LOD and LOQ value were found to be 0.54 and 1.64 ppm for Cefixime trihydrate and 0.77 and 2.34 ppm for Azithromycin dihydrate respectively. The developed and validated method was successfully used for the quantitative analysis of commercially available dosage form (ZIMNIC -AZ). INTRODUCTION: Azithromycin [9-de-oxy-9a-aza-9amethyl-9a-homoerythromycin A dihydrate] is an Azalide, a subclass of macrolide antibiotics . It acts by inhibiting protein synthesis by binding reversibly to the ‘P’ site of the 50S ribosomal subunit of the bacteria 2, . It is used for Adult and Pediatric 4, 5 infections. e.g., Respiratory tract infection 1, 6, 7, , Skin, Soft tissue infections, Otitis media 1, 9, , Sinusitis, Pharyngitis, Acute bronchitis, Community-acquired Pneumonia, Cystic fibrosis 11, , Tonsilitis , Anti-inflammatory in COPD Patient , in P. Falciparum Malaria with other Antimalarial drugs , Typhoid fever 16, . Cefixime (6R, 7R)-7-[2-(2-amino-4thiazolyl) glyoxylamido]8-oxo-3-vinyl-5-1 –azabicyclo [4.2.0] oct-2ene-2-carboxylicacid,7-9z)-[o carboxymethyl)oxime] trihydrate is third generation cephalosporin antibiotic. It is under the category of β-Lactam Antibiotics/Cell Wall inhibitor. It Acts by inhibiting an enzyme Transpeptidase, involved in the building of Bacterial Cell Walls . It is used in Lower Respiratory Tract Infections 19, 20, , Acute Urinary Tract Infections 21, , Biliary Tract Infections , Sinusitis , Acute Otitis Media , Peptic Ulcer . Combination of Cefixime Trihydrate and Azithromycin Dihydrate has a Synergistic effect. The effect of Cefixime Trihydrate against Neissaria gonorrhoeae can be significantly enhanced in combination with Azithromycin Dihydrate . This Combination is used in treatment of Uncomplicated Gonococcal Urethritis, Gonorrhoea , Typhoid Fever 31, . Both the drugs are official in Indian pharmacopoeia 2010 33, . Literature survey reveals that HPLC , RPHPLC 36, 37, , UV-Visible Spectrophotometry 39, 40, 41, , UPLC , methods were reported for the estimation of Azithromycin Dihydrate alone or in combination with other drugs except Cefixime Trihydrate and UV-Visible Spectrophotometry 44, 45, 46, , HPLC 48, 49, , RP-HPLC