dissolution of poorely soluble drug

[atgaadesh]

I am working on a poorly soluble drug. I want to analysr the DR tablet of that drug., the problem i am facing is with the preparation of standard for acid stage.As the copmound is insoluble in acid, For the standard preparation it is necessary to add some amount of organic solvent but on the addition of 0.1 M Hcl the drug gets precippitated (even after addition of 50% organic)
Will anybody throw some focus in such case for the preparation of standard as it is necessary for me to know the % release in acid stage

[harthur]

I am working on a poorly soluble drug. I want to analysr the DR tablet of that drug., the problem i am facing is with the preparation of standard for acid stage.As the copmound is insoluble in acid, For the standard preparation it is necessary to add some amount of organic solvent but on the addition of 0.1 M Hcl the drug gets precippitated (even after addition of 50% organic)
Will anybody throw some focus in such case for the preparation of standard as it is necessary for me to know the % release in acid stage
Do you add any surfactant (SLS, CTAB etc) to your dissolution media in the acid stage? If so, try dissolving your standard in acid that has the same concentration of that surfactant as your dissolution media. Also, if you could find a way to show that the absorabance of your acidic media is no different from the absorbance of your buffer media (basically that you don't get response differences based solely on the media), you may be able to justify using one standard prep (in buffer) for both stages of your dissolution.

[johnt]

Since in a DR formualation the drug is not meant to dissolve in acidic media for any number of reasons ( <10% as per General Chapter <724>). In all DR formulations I have worked on the standards were only ever made up in the 2nd stage media.

[atgaadesh]

whether it is acceptable to add surfactant in acid stage?
If yer would anybody can give me the refrence of that?


Do you add any surfactant (SLS, CTAB etc) to your dissolution media in the acid stage? If so, try dissolving your standard in acid that has the same concentration of that surfactant as your dissolution media. Also, if you could find a way to show that the absorabance of your acidic media is no different from the absorbance of your buffer media (basically that you don't get response differences based solely on the media), you may be able to justify using one standard prep (in buffer) for both stages of your dissolution.