Visual compatibility of ondansetron and dexamethasone

Compatibility and Physical Properties of Dexamethasone-Ondansetron Intravenous Admixture

Purpose: This work aimed at evaluating the impact of different concentrations and final volumes on the compatibility and physical properties of dexamethasone-ondansetron intravenous (IV) admixture. Methods: The IV admixture of dexamethasone-ondansetron was prepared at different concentrations using normal saline solution as solvent. The final volume of the IV admixture was prepared at 50 and 100 ml. Turbidity was measured as an indicator of physical compatibility of the IV admixture of dexamethasone-ondansetron using UV-visible spectrophotometer and the pH of the IV admixture was measured on day 0, 7,14, and, 21 as an index of chemical stability. Also, the particle size and potential molecular interactions of the admixtures were determined using particle size analyzer and Fourier Transform infrared spectrometry analysis, respectively. Additionally, the effect of preservatives on the IV admixture was also evaluated. Results: Precipitation was observed for mixtures with amounts of dexamethasone and ondansetron exceeding 8 and 16 mg, respectively, in a final volume of 50 ml. For all mixtures with final volume of 100 ml, clear solutions void of any precipitates were observed. The pH of the solution had no effect on the precipitation of the dexamethasone-ondansetron during storage up to 21 days. Analyses of the precipitate formed revealed the presence of molecular interactions between dexamethasone and ondansetron. The benzyl alcohol used as a preservative affected the compatibility of the IV admixture compatibility. Conclusion: Thus, for the preparation of clear, physically compatible normal saline solutions of dexamethasone-ondansetron IV admixture, the maximum amounts of the respective drugs should not exceed 8 and 16 mg in total volume of 50 ml or 20 and 16 mg in a final volume of 100 ml.

Compatibility of dexamethasone sodium phosphate with 5-HT3 receptor antagonists in infusion solutions: a comprehensive study

Objectives

Patients can benefit from the coadministration of several medications because of the shorter infusion time and more rapid administration. The use of extemporaneously prepared admixtures of dexamethasone sodium phosphate (DSP) and 5-HT₃ receptor antagonists (5-HT3RAs) must be supported by sufficient documentation of their compatibility. The objective of this study was to comprehensively investigate the compatibility of DSP with 5-HT3RAs in infusion solutions.

Methods

Admixtures of DSP with six different 5-HT3RAs (ondansetron hydrochloride, tropisetron hydrochloride, dolasetron mesylate, azasetron hydrochloride, palonosetron hydrochloride and ramosetron hydrochloride) were prepared in non-polyvinyl chloride (non-PVC) infusion bags filled with 5% glucose or 0.9% NaCl. Bags were stored at ambient temperature (25±2°C) without protection from light. Samples were taken immediately after preparation (0 hour) and at predetermined intervals (12, 24 and 48 hours after preparation). Particulate matter of admixtures was inspected visually and particles were counted with a particle counter. The pH of each sample was also determined. Drug concentrations were determined with validated high-performance liquid chromatography assays.

Results

No visible haze or particulate formation, colour change or gas evolution and no notable changes in pH were observed, and particulate matter was acceptable up to 48 hours. All preparations maintained more than 90.0% of the initial concentration over the study period.

Conclusions

All the admixtures of DSP and the 5-HT3RAs studied were compatible and stable for at least 48 hours in a 5% glucose injection or a 0.9% NaCl injection stored in non-PVC infusion bags under ambient conditions.