Quality Assessment of Marketed Oral Paracetamol Liquid Formulations: Influence of Storage Conditions on pH and Viscosity
Year: 2026
Type: article
Abstract: Introduction: Paracetamol oral liquid formulations are widely used, especially in pediatric populations, making their quality and stability essential for ensuring safety and therapeutic efficacy. Variations in storage conditions may significantly affect their physicochemical properties. Objectives This study aimed to evaluate the quality of selected marketed oral paracetamol liquid dosage forms by assessing pH and viscosity and investigating the impact of different storage conditions. Methods: A laboratory-based experimental study was conducted on sixteen commercially available oral paracetamol liquid formulations collected from pharmacies in Karbala, Iraq. The physicochemical parameters evaluated were pH and viscosity. Samples were analyzed at room temperature and after storage under two conditions: refrigeration (4–8°C) and direct sunlight exposure for two weeks. All measurements were performed in triplicate, and results were expressed as mean ± standard deviation. Results: At room temperature, most formulations exhibited mildly acidic pH values (2.63–5.04) and acceptable viscosity ranges. Refrigeration resulted in moderate increases in both pH and viscosity without indicating significant instability. In contrast, exposure to direct sunlight caused a marked decrease in pH (1.31–1.95) and variable changes in viscosity, suggesting potential degradation under environmental stress. Suspension formulations generally demonstrated higher viscosity compared to syrups. Conclusions: Most marketed oral paracetamol liquid formulations maintained acceptable physicochemical properties under normal storage conditions. However, exposure to direct sunlight significantly affected stability, particularly pH, indicating potential degradation. Proper storage conditions, especially protection from light, are critical to ensure product quality, safety, and therapeutic effectiveness.
Source: Journal of chemical health risks
Author: Qasim Allawi Bader
Institution: Al-Zahraa University for Women
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7217513632