Rapamycin in lecithin-based formulations to increase bioavailability

Hi, I recently acquired a quantity of rapamycin powder. Rapamycin has good solubility in lecithin so I’ve tried dissolving 10 mg of rapamycin powder into 0.5 mL liquid lecithin for a weekly dose. It appears to completely dissolve after a few minutes. Judging from the literature, rapamycin becomes more bioavailable when dissolved in lecithin-based formulations. I wonder if there are others in this group who have tried this approach and if they can share any thoughts about how this works for them. Thanks.

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I’ve never heard of this. You should do a sirolimus blood test after ingesting it to see how effective it is.

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FWIW

Take a dose of your compound, then do a blood test{to measure the rapamycin level] within 2 hours of taking.

You will have an idea of how much is absorbed.

Liposomal rapamycin!

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  • Rapamycin Instability: Rapamycin is highly susceptible to rapid degradation in highly acidic environments, such as the stomach (pH 1.2), with studies showing almost complete degradation (below 2%) within 30 minutes in simulated gastric fluid when unformulated.

  • Lecithin’s Role: While lecithin is a common pharmaceutical carrier that can help with drug solubility and absorption, and a component of some protective nanoparticle formulations, dissolving rapamycin powder in lecithin alone does not provide a sufficient barrier to the harsh acidic conditions of the stomach.

Even a liposomal rapamycin would experience very significant degradation by stomach acid.

Possible alternative to enteric encapsulation:

New nanoformulation of rapamycin Rapatar extends lifespan in homozygous p53−/− mice by delaying carcinogenesis - PMC.

Rapamycin powder has DIY uses in:

  • Skin cream or treatments
  • Hair restoration
  • Tooth and flossing paste
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Why is this a problem? Enteric-coated capsules are readily available in the US. That’s what I use. I insert already coated Rapacan tablets into enteric-coated capsules and take them with olive oil. Maybe overkill, but that is what I do.

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I’m intrigued. What’s your reasoning for double-encapsulation?

What’s your reasoning for double-encapsulation?
Because I did some experiments with the Rapacan and Zydus tablets, which I posted on another thread a long time ago.
When the Rapacan and Zydus tablets were dropped into a beaker filled with water and a little hydrochloric acid to make a solution with a pH of average stomach acids, they dissolved in ~ 5 minutes.
So, I now put my tablets in enteric-coated capsules to help bypass the stomach and get into the lower digestive tract.
Here is a clip of the experiment. I have shortened it to show just from the time it was mostly disintegrated (5 minutes) until the time they were completely dissolved( ~10 min.) The cloudiness is from the excipients.