Stability of Commercially Available Grape and Compounded Cherry Oral Vancomycin Preparations Stored in Syringes and Cups.

The purpose of this study was to evaluate the stability of two preparations of vancomycin oral solution in two different storage containers, capped amber oral-dosing syringes and heat-sealed oral-dosing cups, stored under refrigerated conditions. Commercially available grape-flavored vancomycin oral preparation and compounded vancomycin for intravenous use in cherry syrup oral preparation were divided into 5-mL aliquots into heat-sealed plastic dosing cups and capped oral-dosing syringes. All samples were stored under refrigeration (2°C to 8°C) and evaluated at days 0, 3, 7, 14, 30, 60, and 90. For each evaluation, samples were visually inspected and analyzed for potency using a stability-indicating high-performance liquid chromatographic method with ultraviolet detection. Over the study period, at least 90% of the initial concentrations for the preparation and the product in both storage containers were retained at 60 days. The commercially available oral vancomycin further demonstrated stability within 90% out to 90 days in the syringe and the unit-dose cups. Visual inspection revealed no changes in the grape-flavored vancomycin oral preparation, but a detectable red-dye precipitate could be seen in the crevices of the dosing cups from the vancomycin in cherry syrup oral preparation after 60 days. Commercially available grape-flavored vancomycin oral preparation was stable up to 90 days, and com- pounded vancomycin for intravenous use in cherry syrup oral preparation maintained stability for 60 days when dispensed in capped amber polypropylene oral-dosing syringes and heat-sealed plastic dosing cups when stored at refrigerated conditions.