Stability consideration in extemporaneous omeprazole suspension

Abstract

Omeprazole (OMP) is a drug used to treat gastroesophageal reflux disease (GERD). Pharmacists also use commercially available capsules of OMP to prepare extemporaneous suspensions for juvenile and geriatric patients and other patients who are unable to swallow capsules. The stability of extemporaneous preparations should be determined on a regular basis in hospital settings. The aim of this study was to evaluate the effect of temperature on the stability of an OMP extemporaneous suspension. A 2mg/ml OMP extemporaneous suspension was prepared and transferred into plastic bottles for storage at 4±3 °C (refrigerated), 25±5 °C (room temperature) and 45±5 °C (accelerated temperature). After 0, 7, 14, 28, 60, and 90 days, samples were evaluated for appearance and OMP content was determined by high-performance liquid chromatography (HPLC). The percentage deterioration in OMP content was determined for chemical stability. The color of the OMP solutions changed from brownish to dark purple after 7 days at all three storage temperatures. The OMP content of the extemporaneous solutions remained above 90% for 28 days at the refrigerated temperature (90.16±1.70%) and for 7 days at room temperature (92.09±3.44%). There was no OMP detected after day 0 at the accelerated temperature. To conclude, OMP extemporaneous suspensions can be safely stored at 4±3 °C for 28 days. These results will provide hospital pharmacists with stability data to use as a guideline for appropriate storage conditions of OMP extemporaneous preparations.