Study of celecoxib dissolution thermodynamics in mixed solvents of propylene glycol and ethanol at various temperatures

Abstract

Due to the low water solubility of most drugs, improving this feature is one of the important steps in drug research and development. One of the simplest and oldest ways to increase solubility is the use of cosolvent. In addition, to understand the effect of construction parameters in the increasing the solubility of drugs and also to predict their solubility in different solvent systems to save time and money, modeling can be used with the various mathematical models. Aim: In the present study, the solubility and density of celecoxib in a mixture of ethanol + propylene glycol solvents in the temperature range of 293.2 to 313.2 K were investigated. The correlations between the obtained data and different models of solubility have also been investigated. Method: In this study, the shake-flask method has been used. In this method, after preparing and saturating the selected solvent mixture with the studied drug, it is placed on the shaker for a certain time inside the incubator at a certain temperature until the solution is saturated and reaches equilibrium. Then the solution is centrifuged and after proper dilution, its absorption is taken at the maximum wavelength for the drug and the concentration of saturated solutions is obtained using the drawn calibration curve. Finally, the correlation of experimental data with computational models is examined. Results: The solubility of celecoxib is directly related to the increase in temperature, and ethanol in the solvent mixtures. The solubility increases with increasing temperature. Also, by increasing the mass fraction of ethanol solvent in ethanol + propylene glycol system, celecoxib solubility increases exponentially. Conclusion: The obtained data show that the highest solubility of celecoxib with increasing temperature and cosolvent. The obtained data analyzed with different models and the constants of each model were calculated.