Comparison of Sedimentation Stability of Azithromycin Dihydrate Suspensions using near Infrared Extinction Profiles with Different Suspending Agents

The aim of the study is to formulate and evaluate the sedimentation stability of the prepared azithromycin suspensions in a rapid way by employing near infrared transmission measurements. The mucilage extracted from Plantago ovata seeds was used as one of the suspending agents along with the traditional suspending agents like MC, HPMC and SCMC. Stability studies of suspensions are very important to enable the patient to receive the intended amount of the drug(s) in the dose administered. Physical stability of azithromycin suspensions was studied in terms of sedimentation stability in a rapid way employing infrared extinction profiles by using the instrument separation analyzer (LUMiReader®) in the present work. The LUMiReader® instantaneously measures the extinction profiles of the transmitted light across the entire length of a suspension sample employing STEP-Technology (Space-and Time-resolved Extinction Profiles Technology). Instability indices determined on different suspension formulations indicated that POM and MC are preferable suspending agents for the preparation of stable suspensions of azithromycin.