solubility problem

[subathrai]

glimepride
many records says that it is soluble in methanol
bt it is not easily soluble in methanol, on sonication it is soluble but after few minutes it settles down
how to overcome this?

[grzesiek]

maybe lowering concetration will work
what records?

[krickos]

Hi

the EP monograph for Glimepride states:

Solubility: practically insoluble in water, soluble in dimethylformamide, slightly soluble in methylene chloride, very slightly soluble in methanol.

So "in fact" very slightly soluble in methanol it seems. Below is EPs definition of solubility terms.

Solubility . In statements of solubility in the Characters section, the terms used have the following significance, referred to a temperature between 15 °C and 25 °C.
Descriptive term Approximate volume of solvent in millilitres
per gram of solute
Very soluble less than 1
Freely soluble from 1 to 10
Soluble from 10 to 30
Sparingly soluble from 30 to 100
Slightly soluble from 100 to 1000
Very slightly soluble from 1000 to 10 000
Practically insoluble more than 10 000

The term ‘partly soluble’ is used to describe a mixture where only some of the components dissolve. The term ‘miscible’ is used to describe a liquid that is miscible in all proportions with the stated solvent.