Revision of USP Chapter <1236> Solubility Measurements Published for Comments

In the Pharmacopeial Forum, PF 49(1), a proposal for a revised USP General Chapter <1236> Solubility Measurements was published. Based on comments received, some revisions were made in addition to those proposed in PF 48(2).

According to the briefing notes, the following changes were made:

• "Update the concentrations for sodium taurodeoxycholate, sodium oleate, and lecithin in porcine simulated gastric and intestinal fluids in Solubility Measurements in Biorelevant Media.
• Update all tables in Solubility Measurements in Biorelevant Media to have the values in g/mL adjusted to the appropriate molecular weight of the compounds. Modify the mM concentration of sodium chloride in Table 5 to be in accordance with the value stated in (25). Adjust concentrations in Table 11 to g/L.
• Revise the text in Sample Preparation to indicate that it is mandatory to start with a saturated solution.
• Modify the text in the introductory paragraph of Experimental Methods, Method for Determination of Equilibrium Solubility, Saturation Shake-Flask Method to allow for the use of buffer solutions other than those recommended by USP."

Comments can be submitted until 31 March 2023. The draft of the revised chapter is available on PF Online.