In Vitro Antibacterial Susceptibility Test of Tridosil and Azimex-500

Abstract

Azithromycin IS a semi-synthetic macrolide antibiotic chemically related to erythromycin and clarithromycin. It is used to treat certain infections caused by bacteria, such as bronchitis, pneumonia, sexually transmitted diseases (STD) and infections of the ears, lungs, skin, and throat. Quality of drugs must be controlled to get desired therapeutic effect. In a pharmaceutical sense, quality means checking and directing the degree or grade of excellence of processes and products. Antimicrobial susceptibility test is one of the quality control tests to estimate the quality and purity of antibiotics. It is performed by using disk diffusion test. The objective of the thesis is to measure the sensitivity and purity of the antibiotic by comparing with the standard. It is significant to determine the quality and purity of antibiotics because of rapid occurrence of antibiotic resistance due to use of substandard or poor quality drugs. The test was performed using Tridosil and Azimex-500 in three different concentrations such as 50 n;g, 75 n;g and 100 n;g. Three different species of bacteria such as E. coli, Staphylococcus aureus, Salmonella typhi were inoculated on nutrient agar plates and different concentrations of sample were applied by disc diffusion method and incubated overnight. Inhibitory activity of the antibiotic was measured as zone of inhibition in mm. The zone of inhibition of the sample was compared with the zone of inhibition of the standard. Results show that both Tridosil and Azimex-500 contain sufficient amount of active ingredient which is required to achieve desired therapeutic activity. It indicates that the samples of different brands are manufactured according to GMP guidelines and have the quality which meets the standard specifications.