Solubility of Amoxicillin Trihydrate Hydrochloride in Water

Objectives: This study aims to determine the solubility of amoxicillin trihydrate hydrochloride in water at different temperatures, addressing the scarcity of solubility data for this substance in the literature. The research focuses on the solubility behavior of the semi-synthetic antibiotic, part of the β-lactam group, widely used orally. Theoretical Framework: Amoxicillin is a β-lactam antibiotic of great therapeutic importance. Its solubility is relevant to the effectiveness of oral formulations and varies according to temperature. The literature on the solubility equilibrium of this compound is limited, motivating new studies that assist in the development of pharmaceutical solutions and the understanding of its physicochemical properties. Method: The solubility of amoxicillin trihydrate hydrochloride was determined at three temperatures: 298.15 K, 309.15 K, and 318.15 K, using the UV spectrophotometry method. The experiment involved 3 hours of stirring and 2 hours of decantation, with a 1 mL aliquot taken for analysis. The samples were diluted in 100 mL volumetric flasks and analyzed by spectrophotometer. Results and Discussion: The experimental results allowed correlating the solubility of amoxicillin trihydrate hydrochloride with empirical equations from the literature. The solubilities obtained demonstrated precision, with low relative deviation between the experimental values and those calculated by the equations. This indicates that the empirical models are adequate for predicting solubility behavior at different temperatures. Research Implications: The research contributes to enriching the solubility database of antibiotics, essential for drug formulation and the development of new therapeutic applications. The precision of the experimental data supports future studies in the field of pharmacology and chemical engineering, particularly in the context of solid and liquid formulations. Originality/Value: The study is original in addressing the solubility of amoxicillin trihydrate hydrochloride in water at different temperatures, filling a gap in the literature. Additionally, the use of UV spectrophotometry and the correlation of the data with empirical equations reinforce the validity of the results, making it valuable for researchers and professionals in the pharmaceutical sector.