Abstract:OBJECTIVE To introduce the basic procedure and technical requirements of equilibrium solubility experiments and provide reference for design and conduct of equilibrium solubility experiments scheme. METHODS The concept and influence factors of solubility, principle and determination method of solubility experiments, equilibrium solubility project of world health organization were analyzed. RESULTS The influence factors of equilibrium solubility include composition of buffers, temperature, time of oscillation, time of sedimentation, techniques for separation of solid and liquid phases etc. CONCLUSION To ascertain the BCS classification of drugs, the first step is to determine the equilibrium solubility of drugs under physiological pH conditions. To date, there is no accepted standard method for the determination of equilibrium solubility. This paper introduces the basic procedure and technical requirements of equilibrium solubility experiments recommended by WHO, which would provide instructive and practical assists to conduct of equilibrium solubility experiments and standardize its application in BCS classification and biowaiver.
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