Losartan potassium liquid formulation for paediatric hospital use: development and stability evaluation.

Objectives: This study aimed to develop a liquid oral formulation containing losartan potassium, an angiotensin II receptor antagonist drug used for its antihypertensive activity, and to perform a preliminary stability assessment under different temperatures and packages to ensure paediatric therapeutic adherence and facilitate the hospital routine.

Methods: A syrup containing losartan potassium (1.0 and 2.5 mg/mL) (excipients: potassium sorbate, sucrose (85%), water, citric acid and raspberry flavouring) was prepared. The packaging was carried out in amber polyethylene terephthalate (PET) and amber glass bottles (in triplicate) under the following conditions: (a) room temperature (15-30°C); (b) refrigeration (2-8°C); and (c) oven temperature (40°C) for 28 days. An analytical method by high performance liquid chromatography using a reverse-phase column was also developed and validated for quantitative determination of the drug in the formulations.

Results: The analytical method showed satisfactory linearity, detection and quantification limits, precision, accuracy and robustness. Samples at room temperature maintained content values between 90% and 110% for 7 days, while those stored under refrigeration maintained a homogeneous appearance and content between 90% and 110% for a period of 21 days. Values of pH stayed in a narrow range. Viscosity results were between 40.1 and 49.2 centipoise (cp) for glass bottles and 42.4 and 54.7 cp for PET bottles.

Conclusions: A simple and economical losartan potassium liquid formulation was produced and was shown to be stable under refrigeration for 21 days in both PET and glass packages.