Procal Co. (= Sodium Fluoride 25 mg) is out of the trade. We are asked to produce this as a magistal preparation for the treatment of otosclerosis.

This is without a doubt a highly-dosed tablet with fluoride. I have not been able to find anything about the composition of Procal tablets. But my searches indicate that such tablets are made gastric juice resistant. Therefore also for capsules. But this gastric juice resistance only causes less side effects at the stomach level; I noted that efforts are also being made to slow the release of fluoride, even in the small intestine. That is why I would like to make a proposal which I cannot estimate the feasibility of, but perhaps worth trying. Indeed, I would try to envelop the fluoride with some fat. We could do this in two ways. In The first case, I would make a dilution 1 in 10 of my amount of fluoride (for 60 capsules 1.5 g of Nafluoride + 15g lactose) and spray this with 5 ml of a solution in ether, which contains 1.5 g suppository mass. This should be done under continuous rubbing with the pestle. Once all ether evaporates should be brought to volume with lactose for BV 60 capsules. If the final mixing poses problems then, as a second method, there is nothing else left than the total powder mass with suppository mass to envelop. Maybe we use 3g suppository mass? It is very difficult to prescribe the right quantities without any experiments.
If this idea is not feasible then a gastric juice resisitence can only be thought of.