Study of equilibrium solubility measurement by saturation shake-flask method using hydrochlorothiazide as model...

Area of Science:

• Pharmaceutical Science
• Analytical Chemistry

Background:

• The classical saturation shake-flask method is a standard technique for determining drug equilibrium solubility.
• Accurate solubility data is crucial for drug formulation and development.
• Several experimental factors can influence the reliability of solubility measurements.

Purpose of the Study:

• To investigate the impact of various experimental conditions on equilibrium solubility measurements.
• To develop a refined, more efficient protocol for determining drug solubility.
• To provide recommendations for best practices in analytical methodology.

Main Methods:

• Utilized hydrochlorothiazide as a model compound to examine experimental variables.
• Systematically modified temperature, sedimentation time, buffer composition, and solid-liquid separation techniques.
• Assessed the influence of solid excess and stirring time on solubility results.
• Developed and validated a new, shorter protocol using five additional drug compounds.

Main Results:

• Temperature, sedimentation time, buffer composition, and separation technique significantly affected equilibrium solubility.
• Variations in solid excess and stirring time had a less pronounced influence on the results.
• The newly developed protocol demonstrated reliability in measuring equilibrium solubilities for diverse drug compounds.

Conclusions:

• Optimizing experimental conditions is essential for accurate drug solubility determination.
• The new protocol offers a more efficient and reliable method for equilibrium solubility measurements.
• Adherence to recommended analytical practices enhances the quality of solubility data in pharmaceutical research.