Using A Sonicator Or Mechanical Homogenizer To Mix Solutions

[dietcoke1987]

What do you think about adding 5% oleic acid or azone to ethanol/pg solutions to increase permeation?

Seems helpful but the thing to keep in mind here is it's a balancing act so to speak. You want it to penetrate but you don't want it so much so that it's almost completely mobilized and doesn't stay localized. We aren't trying to administer a drug to go systematic and be wasted. We want it to stay localized and concentrated. I think that's why the other guy was talking about slow release which is a great idea and why I replied to him. Liposomal formulations do tend to stay more localized than a straight up solution with penetration enhancers. Also why fat soluble stuff is better for topical because it wants to stay in place more than get carried away by the blood stream. It's why dutasteride is likely better suited for topical use than finasteride. That's where I'm coming from.

 

[pegasus2]

Seems helpful but the thing to keep in mind here is it's a balancing act so to speak. You want it to penetrate but you don't want it so much so that it's almost completely mobilized and doesn't stay localized. We aren't trying to administer a drug to go systematic and be wasted. We want it to stay localized and concentrated. I think that's why the other guy was talking about slow release which is a great idea and why I replied to him. Liposomal formulations do tend to stay more localized than a straight up solution with penetration enhancers. Also why fat soluble stuff is better for topical because it wants to stay in place more than get carried away by the blood stream. It's why dutasteride is likely better suited for topical use than finasteride. That's where I'm coming from.

Dutasteride is very poorly absorbed. Only trace amounts make it to the follicle in conventional vehicles without microneedling. That's why it's so hard to find topical dutasteride vs finasteride, the former is really only used with mesotherapy or microneedling. Lipophilic compounds actually make better drugs because they penetrate the skin better, not because they stay in place. Very lipophilic compounds though do not penetrate. Dutasteride has a logP of 5.79. Anything with a logP over 4 is difficult to absorb. Also, anything with a low logP is difficult to absorb. Hydrophilic compounds don't go through the skin to the bloodstream as you say, they actually aren't able to penetrate the skin. Highly lipophilic compounds can't either. If you want to dutasteride to penetrate you need to use a PG and a fatty acid

This is an excellent book for learning about penetration of topical drugs.

 

[John Difool]

Using a sonicator, would you sonicate the drug with DMSO first then add Ethanol : PG or add Ethanol to DMSO + drug first ? With low volume preparations it would seem easier to get a higher volume but is it more effective?

 

[Throwaway94]

Using a sonicator, would you sonicate the drug with DMSO first then add Ethanol : PG or add Ethanol to DMSO + drug first ? With low volume preparations it would seem easier to get a higher volume but is it more effective?

Are you trying to push the absolute highest end of the drug's solubility in DMSO / ethanol?

 

[John Difool]

Yes pretty much. I also noticed that even if I stir and shake the powders in DMSO the result looks always milky with floating particles.

 

[Throwaway94]

Yes pretty much. I also noticed that even if I stir and shake the powders in DMSO the result looks always milky with floating particles.

Do you mean it starts clear and then precipitates when you agitate it?

But yeah I'd start with the DMSO and not sonicate too long - say 10 mins or so. Then add your ethanol and pg. If you notice it precipitate you can still sonicate it again.