In vitro Comparison of Generic and Branded Preparations of Amoxicillin with Potassium Clavulanate

Abstract

Introduction: The Medical Council of India (MCI) has guidelines for physicians to prescribe drugs with generic names. But physicians and patients might have prejudices against generic drug substitution or concerns regarding quality and generics effectiveness. If the drugs are ineffective, they can result in adverse clinical outcomes such as treatment failure. According to WHO, β-lactams are the most common substandard drugs to be produced amongst antibiotics. Aim: To evaluate and compare invitro efficacy of generic and branded preparations of Amoxicillin with Potassium Clavulanate. Materials and Methods: One generic (C) and 5 branded formulations (A,B,D,E,F) of amoxicillin with potassium clavulanate were taken for microbiological assay. Coding was done. Sterile disks were instilled with 10µl of preparations and disk diffusion was screened by Kirby Bauer Method using Mueller Hinton Agar. Bacterial Strains used were Staphylococcus aureus (S. aureus) and Escherichia Coli. Zone of inhibition was measured. Statistical Analysis was done using repeated measures oneway ANOVA followed by Tukey’s test. Results: Disk Diffusion test showed that branded Drug F has statistically significant less zone of inhibition (p < 0.001) for S. Aureus and (p < 0.05) for E.coli in comparison with generic drug C. Zone of inhibition of branded Drug A, B & E was comparable with the generic drug C. Conclusion: The results of this study indicate that the generic drug tested was equally effective compared to the tested branded drugs except branded Drug D and F. This suggests that efficacy of generic drug is equivalent to branded drugs and maybe used interchangeably with branded drugs.

Keywords

• antibiotic
• disk diffusion
• microbiological assay