- Given your nickname I assume you’re female. Else, it is recommended not to handle female hormones (at least not on a regular basis), even with your safety equipment.
- Progesterone is considered a prescription drug in many countries.
- It isn’t that pH sensitive, best to keep it below pH 7.
- Interactions: Could you be more precise? Chemically, it’s quite stable, if that’s what you’re asking. Just to be on the safe side, don’t combine with good nucleophiles such as free thiols.
- It’s best soluble in medium polarity solvents such as alcohols (progestogel, a pharmaceutical product, is a hyroalcoholic gel). What you could or have to use depends on the final concentration and where that cream will be applied.
- You could also go for a suspension instead of a solution: jojoba oil is used in magistral preparations to obtain a 10% stock suspension which can then be integrated into oilier creams.
- Other preparations such as vaginal suppositories (suspensions, not solutions) are based on macrogols.
May I ask what you’re planning? What you’re planning doesn’t sound like cosmetics…