# Characterization of Liquid Dosage Forms of Atenolol and Enalapril Maleate for Oral and Enteral Feeding Administration

## TL;DR

This study evaluates liquid formulations of atenolol and enalapril maleate for oral and enteral use, ensuring stability and palatability for vulnerable patient groups.

## Contribution

The study introduces a bitter-blocking vehicle (SuspendIt®) and evaluates stability of formulations for pediatric and geriatric use.

## Key findings

- The formulations were suitable for enteral feeding tube administration due to good injectability.
- SuspendIt® effectively masked the bitterness of both drugs.
- Atenolol remained stable for 180 days at both 25 °C and 5 °C, while enalapril maleate was stable for 60 days at 25 °C and 180 days at 5 °C.

## Abstract

The limited availability of pharmaceutical formulations tailored for cardiovascular diseases in both pediatric and geriatric populations generates the need for compounded dosage forms to guarantee precise dosing and medication adherence. This study aimed to analyze the physicochemical properties and stability of formulations of atenolol and enalapril maleate prepared with a proprietary oral vehicle, SuspendIt®. To this end, palatability, injectability, pH, rheological behavior, and physical, microbiological, and chemical stability over a 180-day storage period at 25 °C and 5 °C were evaluated. Injectability tests confirmed the suitable use of both formulations for administration through enteral feeding tubes. By using a potentiometric electronic tongue, it was confirmed that the SuspendIt® vehicle effectively served as a bitter-blocking strategy for atenolol and enalapril maleate. Adequate stability throughout the storage period was confirmed in terms of the mechanical properties, pH, and effectiveness of the preservative system. The atenolol concentration remained above 90% of the initial amount, while the concentration of enalapril maleate decreased to 88% after 90 days of storage at 25 °C. In summary, the atenolol formulation maintained suitable chemical, physical, and microbiological stability after 180 days at both storage temperatures, while the enalapril maleate formulation remained stable up to 60 days at 25 °C and for 180 days at 5 °C.