Beyond-use dating of lidocaine alone and in two "magic mouthwash" preparations.

PURPOSE: Beyond-use dating (BUD) of lidocaine alone and in two "magic mouthwash" preparations stored in amber oral syringes at room temperature was determined. METHODS: Two formulations of mouthwash containing oral topical lidocaine 2% (viscous), diphenhydramine 2.5 mg/mL, and aluminum hydroxide-magnesium hydroxide-simethicone were prepared in 1:1:1 and 1:2.5:2.5 ratios, divided into 3-mL samples, and stored in unit-dose oral amber syringes. Unit-dose single-product lidocaine samples were also prepared to serve as controls and stored in oral amber syringes. The lidocaine concentrations in these samples were measured periodically for 90 days. A stability-indicating high-performance liquid chromatographic method was developed and validated for system suitability, accuracy, repeatability, intermediate precision, specificity, linearity, and robustness. RESULTS: Based on the calculated percentages versus the initial concentration and the results from an analysis of variance comparing the two formulations, a BUD of 21 days is deemed appropriate for both magic mouthwash formulations. Based on the stability data, published safety concerns, and lack of efficacy in combination, packaging and dispensing lidocaine separately from other ingredients are recommended when administering magic mouthwash mixtures. Utilizing a 90-day BUD, lidocaine can be packaged separately from other magic mouthwash ingredients in individual dosage units and applied to the oral cavity using the swish-and-spit method. The delivery of the diphenhydramine and aluminum hydroxide-magnesium hydroxide-simethicone could be separated, allowing for a swish-and-swallow method of administration. CONCLUSION: A BUD of 21 days is recommended for lidocaine prepared with diphenhydramine and aluminum hydroxide-magnesium hydroxide-simethicone in ratios of 1:1:1 and 1:2.5:2.5 and stored at room temperature in amber oral plastic syringes.

Stability of sildenafil in combination with heparin and dopamine.

PURPOSE: The stability of sildenafil in combination with heparin and dopamine was evaluated. METHODS: A stability-indicating high-performance liquid chromatography method with ultraviolet detection was developed for sildenafil citrate and validated. The method was applied to the investigation of sildenafil alone, sildenafil with heparin, sildenafil with dopamine, and sildenafil with heparin and with dopamine, all in 5% dextrose injection at room temperature and under refrigeration for 30 days. Samples of 100 µL were pulled from each storage bottle on each sampling day, diluted in mobile phase, and assayed in duplicate. Samples were tested on days 0, 1, 2, 3, 4, 5, 7, 9, 12, 14, 21, and 30. Each preparation was visually inspected for precipitation and color change. The percent recovery in each study sample was determined by comparing the peak area of sildenafil in the sample with the peak area of sildenafil from a freshly prepared 100-µg/mL standard in mobile phase. RESULTS: The sildenafil alone, sildenafil with heparin, and sildenafil with dopamine remained within 90-110% of the expected sildenafil potency for at least 30 days at both temperatures. The preparation of sildenafil with both heparin and dopamine fell below 90% potency after 3 days at room temperature and 21 days in the refrigerator. CONCLUSION: Sildenafil prepared in 5% dextrose injection alone, with heparin, and with dopamine retained over 90% potency after 30 days of storage at room temperature and under refrigeration. Sildenafil prepared with both heparin and dopamine had a potency of <90% after 3 days of storage at room temperature and 21 days of storage under refrigeration.

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.