Stability and Comparative Dissolution Studies of Five Brands of Norfloxacin Tablets Marketed in Addis Ababa, Ethiopia

Abstract

The dissolution profiles of five different brands of norfloxacin (400 mg) tablets designated as A, B, C, D, and E, marketed in Addis Ababa were compared with those of an innovator product (F). The stability of these tablets was evaluated under the influence of accelerated conditions (40 °C + 2 °C and 75% ± 5% RH). The t50% and t90% (time required for releasing 50% and 90% of the drug, respectively) were used as dissolution parameters to compare the dissolution profiles of the tablets. The t50% results indicated that except for Product C, all the others released 50% of the drug below 10.2 min (the time taken by the innovator product to release 50%). However, the t90%s for three products (B, C, and E) were longer (42.1, 37.4 and 29.0 min, respectively) than that of the innovator product (17.6 min) showing slower dissolution rates for the brand products relative to the innovator product. Product D showed a faster dissolution rate than the innovator product with 90% release at 9.8 min. The stability testing revealed that during the six months storage under the accelerated conditions, physical changes like film cracking, decrease in hardness, increase in moisture content and changes in dissolution profiles have occurred. The highest change in drug content was 3.6% at six-months. Accordingly, no significant change in drug content has occurred in any of the investigated norfloxacin tablets stored under stressed conditions for six months.

Keywords: norfloxacin, film coated tablet, dissolution profile, stability, accelerated conditions