We have been making for quite some time for a patient capsules with Na-secobarbital. It is missing as a raw material, only available as a base. Should we consider a change in bioavailability here?

The sodium salt will dissolve faster in the stomach than secobarbital and then converted into fine secobarbital, which is then absorbed into the intestine. I would add to the capsules a quantity of   trisodium citrate   equal to 60% of the amount of secobarbital. We hope that a salt formation "in situ" will occur and so nasecobarbital is formed. Now this is the theory and let us hope that it continues in reality. Perhaps inform your customer that Nasecobarbital is no longer available but that you are attempting to achieve the same therapeutic effect through a detour? Or just wait because if you notify him of a change, your new capsules may already be less   good. Should you use a   larger capsule size, you will need to think of a leugentje to best