@alfredoolivas said in Experiments with transdermal hormones:
Since you're using less common solvents and a long list of excipients, you'll need to make sure every excipient is fully miscible with each other and that your active ingredient dissolves properly in the solvent.
DMI and Propylene Glycol aren’t widely used in labs, so there’s little to no published data on how well hormones like testosterone dissolve in them. And when it comes to other excipients like squalane and IPM, there’s absolutely no data at all on how they interact with DMI or Propylene Glycol. Additionally, there is no data on how IPM interacts with squalane, for example.
Chat GPT is very, very bad at estimating data. It won't estimate figures unless you force it to, for this precise reason. Therefore, ignore its solubility and penetration figures.
The only realistic way you may achieve this is ordering an excess of all of these ingredients and figuring out the miscibility of the active ingredient and excipients by trial and error; and even if you do this, you will have no idea if the active ingredient exists as crystals inside the gel, or if it is dissolved inside the solvent. Pharmaceutical gels are designed to have the active ingredient to be either crystalline or dissolved in the gel; when it's crystalline, the crystals will sit on top of the skin and absorb into the skin, creating a more local effect. When the API is dissolved in the gel, it goes systematic.
You’ve raised some good points :
Miscibility Concerns:
I plan to conduct small-scale miscibility tests for all solvent/excipient combinations before scaling up. If phase separation occurs, I’ll explore emulsifiers or adjust ratios to achieve homogeneity.
Solubility:
propylene glycol (PG) is well-documented for steroids like testosterone, with solubility typically ranging from 50–100 mg/mL. DMSO is also widely used and can dissolve testosterone at high concentrations (>200 mg/mL).
Crystalline vs. Dissolved API:
If undissolved crystals are present, I’ll adjust the solvent blend or increase co-solvent ratios.
