Background Antiarrhythmic beta blocker sotalol is highly effective in the treatment of supraventricular tachycardia in children; approximately 14,000 capsules containing various doses of sotalol hydrochloride were prepared in our pharmacy in the year 2012. No licensed paediatric dosage form with sotalol is available in Europe now.

Purpose To replace the extemporaneous preparation of sotalol-containing capsules with oral liquid for children in hospital pharmacy conditions. To ensure safe formulation of the substance in terms of minimum excipients, suitable flavour, chemical and microbiological stability. To design and verify the method for routine quality control of the final product.

Materials and methods A paediatrics cardiologist was consulted about the development of 5 mg/ml sotalol hydrochloride solution. Potassium sorbate was used as a preservative, sucrose syrup as a sweetener, and citric acid to stabilise the pH value. The stability of the solution was evaluated over 6 months at refrigerated and room temperatures using a validated HPLC method; the pH was measured.

Results The HPLC method verified chemical stability of the solution at + 4°C for 180 days. The concentration of sotalol varied between 98.5-101.0%, potassium sorbate between 95.2-103.2%, the pH value was in a range of 4.16-4.19. In the hospital pharmacy, where the HPLC method is not available, silver nitrate potentiometric titration can be used to determine the sotalol hydrochloride concentration when preparing stock solutions.

Conclusions A stable oral liquid formulation of sotalol was developed and replaced the time-consuming preparation of capsules. The proposed solution has a six months shelf life in the refrigerator, suitable dosage flexibility and easy availability for the paediatric patients. Moreover, the treatment’s safety was increased due to the formulation with documented stability and improved quality control of the final product.

Acknowledgement Supported by MH CZ – DRO, University Hospital Motol, Prague, Czech Republic 00064203; by SVV 2013 267 001 and SVV 2013 267 002, and GAUK 1472213. The publication is co-financed by the European Social Fund and the state budget of the Czech Republic. TEAB, project no. CZ.1.07/2.3.00/20.0235.

No conflict of interest.