Objectives In children, supraventricular tachycardia is the most common form of arrhythmia, and propafenone is an effective class Ic antiarrhythmic agent used in this population. No suitable paediatric-specific, dosing-flexible preparation is available in Taiwan. The objective of this study was to develop a formulation of propafenone oral suspension prepared from commercially available propafenone tablets and commercially available oral syrup vehicles for related patients.

Methods An oral suspension of propafenone hydrochloride at a concentration of 10 mg/mL was prepared by mixing finely grounded propafenone hydrochloride tablets and a 1:1 mixture of Ora-Plus and Ora-Sweet. The beyond-use date was determined by analysing the samples stored at room temperature or 2–8℃ at time 0 and on days 7, 14, 21, 28, 35, 42, 56, and 90. Parameters to be inspected included appearance, pH measurement, high-performance liquid chromatography analysis, and microbial limit tests.

Results On the basis of the physicochemical and microbial stability results, the 10 mg/mL oral suspension of propafenone hydrochloride was stable at 2–8℃ and room temperature for at least 90 days. The suspension did not exhibit significant changes in drug concentration or pH level at any time point. Moreover, no apparent changes or microbial contaminations were observed for at least 90 days.

Conclusions Propafenone hydrochloride in a 10 mg/mL oral suspension prepared by diluting fine powder with a 1:1 mixture of Ora-Plus and Ora-Sweet and stored in high-density polyethylene bottles and has a beyond-use date of 90 days when stored at 2–8℃ or room temperature. This finding enables us to improve the accuracy of dosage administration and reduce the risk of medication errors affecting the paediatric population.