Influence Of Sample Preparation Method On Isothermal Studies During Compatibility Screening Of Ofloxacin; Correlation With DSC Data

Objectives: The compatibility of ofloxacin with somecommonly used diluents has been investigated usingisothermal stability studies (IST) to allow relative ranking.Materials and Methods: The samples were prepared usingthree methods namely physical admixtures (with 5% addedmoisture), slugging and kneading in order to evaluate theeffect of mechanical treatment on the physicochemical stabilityof drug. To further verify the results of IST fresh binarymixtures were subjected to thermal analysis and an attemptwas made to correlate the results obtained from the twostudies.Results: The results from both DSC and IST revealed thatofloxacin was compatible with all the diluents used in thestudy. Among the three methods of sample preparation usedfor the study, the extent of degradation was more or less samein all the three methods indicating least influence of method ofsample preparation on the results of IST.Conclusions: From the study it was concluded that a betterco-correlation could have been obtained had ofloxacin beenmore unstable with few of the excipients than rest, used in thestudy. This way the extent of degradation would bedistinguishing enough to rank the excipients in decreasingorder of stability.