Background In The Netherlands there are no licenced medicines available with hydrochlorothiazide that are suitable for children. Lack of children’s formulations in general may lead to a variety of mixtures of different quality and strength. This may cause medication errors, especially when children receive the same active substance in different formulations and strengths during their hospital stay and after discharge.

Purpose To develop a standardised hydrochlorothiazide liquid formulation with a shelf life supported by stability studies, in order to provide standardised and safe care for children.

Materials and Methods National standard procedures were applied to assess the therapeutic rationale and to design an oral solution for children. HPLC was used to develop a method of indicating stability in order to establish shelf life. A patient information leaflet was designed, also by following a standard procedure.

Nationwide, the quality of hydrochlorothiazide oral liquid preparations was determined pre- and post-introduction of the standardised formulation.

Results

• A therapeutic rationale was established for diuresis.

• A formulation for a robust hydrochlorothiazide 0.5 mg/ml oral solution was optimised for solubility, stability and taste.

• An HPLC method was developed to test stability.

• A shelf life of 6 months was established.

• Publication in the Dutch Formulary.

• A patient information leaflet was produced providing information on indication, use, precautions, interactions and storage.

• Hydrochlorothiazide formulation errors decreased nationwide from 35% to 13%.

Conclusions A robust and stable oral liquid formulation was developed containing hydrochlorothiazide 0.5 mg/ml, which remains stable for 6 months. A patient information leaflet was made available. Standardization and publication in the Dutch Formulary has demonstrably improved the quality of hydrochlorothiazide oral liquid formulations nationwide.

No conflict of interest.