Evaluation of the stability of promethazine hydrochloride in pluronic lecithin organogel and the determination of an appropriate beyond-use date.

Previous reports indicate that pharmacists are assigning a wide variety of beyond-use dates to extemporaneously compounded medications in topical Pluronic lecithin organogel. The objective of this study was to evaluate the stability of promethazine in Pluronic lecithin organogel over a period of six months and to determine an appropriate beyond-use date. A stability-indicating high-performance liquid chromatography method for promethazine in Pluronic lecithin organogel was validated in our laboratory. Samples of each formulation were analyzed by high- performance liquid chromatography at 0, 7, 14, 21, 28, 45, 60, 90, and 180 days. At each time point, the average concentration and average percent of initial concentration were calculated. The beyond-use date was determined at the time period that the samples were physically stable and maintained at least 90% of the initial concentration. Promethazine hydrochloride was chemically stable in Pluronic lecithin organogel for the period of six months. However, the formulation was physically stable only up to 60 days, and the gel matrix showed signs of physical instability at 90 days, therefore, a 60-day beyond-use date is appropriate for this formulation.

Evaluation of the stability of ketoprofen in pluronic lecithin organogel and the determination of an appropriate beyond-use date.

Previous reports indicate that pharmacists are assigning a wide variety of beyond-use dates to extemporaneously compounded medications in topical Pluronic lecithin organogel. The objective of this study was to evaluate the stability of ketoprofen in Pluronic lecithin organogel over a period of six months and to determine an appropriate beyond-use date for this formulation. A stability-indicating high-performance liquid chromatography method for ketoprofen in Pluronic lecithin organogel was validated in our laboratory. Samples of the formulation were analyzed by high-performance liquid chromatography at 0, 7, 14, 21, 28, 45, 60, 90, and 180 days. At each time point, the average concentration and average percent of initial concentration were calculated. The beyond-use date was determined as the time period that the samples were physically stable and maintained at least 90% of the initial concentration. Ketoprofen in Pluronic lecithin organogel was chemically and physically stable for six months when stored at room temperature and protected from light. Therefore, a beyond-use date of six months is appropriate for this preparation.

Evaluation of the stability of fluoxetine in pluronic lecithin organogel and the determination of an appropriate beyond-use date.

Fluoxetine is a commonly prescribed psychotropic medication for a variety of behavioral diagnoses in veterinary practice, and fluoxetine in Pluronic lecithin organogel has been used successfully in treating inappropriate urine spraying in felines. Historically, pharmacists have assigned a variety of beyond-use dates to extemporaneously compound drugs in Pluronic lecithin organogel. The objective of this study was to evaluate the stability of fluoxetine in Pluronic lecithin organogel over a period of six months and to determine an appropriate beyond-use date. A stability-indicating high-performance liquid chromatography method for fluoxetine in Pluronic lecithin organogel was validated in our laboratory. Fluoxetine-Pluronic lecithin organogel 50 mg/mL was prepared by a local compounding pharmacy and analyzed by high-performance liquid chromatograph at 0, 7, 14, 21, 28, 45, 60, 90, and 180 days. Physical stability was also assessed by visual observation. At each time point percent of initial concentration was calculated. The beyond-use date was determined as the time period that the samples maintained at least 90 percent of the initial concentration. At 180 days, the mean percent of initial concentration was 99 +/- 1.5 and, visually, the fluoxetine-Pluronic lecithin organogel retained the original color and consistency, without detectable separation of the different phases of Pluronic lecithin organogel. Since fluoxetine was physically stable and retained greater than 90 percent of initial concentration in Pluronic lecithin organogel for 180 days when stored at room temperature and protected from light, a beyond-use date of 180 days is appropriate.

Evaluation of the stability of acetaminophen in pluronic lecithin organogel and the determination of an appropriate beyond-use date.

Transdermal acetaminophen in Pluronic lecithin organogel (APAP-PLO) has been anecdotally reported as beneficial when used in cancer patients in the hospice setting. However, there is currently no published information regarding the stability of APAP-PLO. The objective of this study was to identify an appropriate formulation of APAP-PLO and to evaluate the stability of that formulation in order to determine an appropriate beyond-use date. APAP-PLO 50% was prepared by a local compounding pharmacy and analyzed at 0, 7, 14, 28, 45, 60, 90, and 180 days using a stability-indicating high-performance liquid chromatographic method. The mean concentrations and standard deviations were determined for each time point. Physical stability was also assessed by visual observation at each time point. The beyond-use date was determined as the time period that the samples maintained at least 90 percent of the initial concentration. At 180 days, the APAP-PLO was physically stable as noted by visual observation, and the concentration was 102 +/- 4.8 percent of initial concentration indicating that a beyond-use date of 180 days would be appropriate for this formulation.