Quality review of compounded oral solution of spironolactone at 5mg/ml in InOrpha^®

Introduction
A compounded oral solution (OS) of spironolactone (SP) was prepared in the pharmacy at a dose of 5 mg/ml in InOrpha^®. This suspension sedimented rapidly. Vigorous agitation (2 minutes) was required to achieve homogeneous resuspension.

Objective
The aim was to evaluate the appropriate use (AU), in terms of resuspension, of OS by the nursing team in paediatric services (paediatric intensive care unit [PICU] and neonatal intensive care unit [NICU]).

Material/Methods
For one month in 2020 and 2022, before each administration of OS from SP in paediatrics, the nurse collected 1 ml of OS after resuspension according to label recommendations (vigorous shaking for 2 minutes). The sample was sent to the control laboratory and quantified using HPLC-UV according to a validated method. Three ’control’ syringes were taken by the pharmaceutical team at the end of production of a compliant batch of OS de SP to assess syringe stability prior to dosing.
The aim was to achieve a target SP concentration of 50 µg/ml ± 10%. Concentrations were expressed as median interquartile range [25;75%]. For each service in each period, a mean bias was calculated ([measured concentration-expected concentration]/expected concentration*100 [%]). Following both collection periods, paediatric ward teams were trained by pharmacy teams in AU.

Results
During the study period, 15 and 18 samples were collected in the PICU and NICU respectively in 2020 and 16 and 16 samples were collected in 2022. In the PICU and NICU, 0% and 28% of samples, respectively, met the expected dose in 2020. The median concentrations were 31.91 RIQ[22.5;43.9] µg/ml for PICU and 39.77 RIQ[33.6;48.6] µg/ml for NICU. The mean bias with respect to the theoretical value was -25% and -16%, respectively. Two months after the study, an AU booster was performed. In 2022, 19 and 0% of PICU and NICU samples, respectively, were found to be compliant in the remote AU follow-up. Median concentrations were 58.64 RIQ [46.1 ;63.7] µg/ml for PICU and 21.41 RIQ [17.8 ;26.0] µg/ml for NICU. Mean biases of +10% and -61% were observed with respect to the theoretical value. Dosing of the 3 control syringes after 1 month of storage was 100% as expected.

Conclusion
This study showed a high variability in SP dosage given for this OS. It can therefore be assumed that this variability, rather than underdosing, did not allow dose adjustment based on monitoring of the clinical-biological constants.
Nursing teams were not able to achieve OS with the expected dose, despite the label mentioning the importance of vigorous and prolonged agitation and training. It is intended to propose a new formulation.