Prednisolone hemisuccinate is a prohibited substance

Prednisolone is a corticosteroid and is a prohibited substance with a similar effect to hydrocortisone. Both prednisolone and hydrocortisone are commercially available as hemisuccinate (succinic acid) derivatives. The ester derivative, hydrocortisone hemisuccinate, is found in the preparation Solu Cortef while the similar ester, prednisolone hemisuccinate, is found in the well-known preparation Solu delta Cortef.

The term ester describes the link of the molecule succinate (succinic acid) to the corticosteroid (prednisolone) which is so-called ester linkage. This linked prednisolone hemisuccinate molecule has enhanced water solubility compared to prednisolone itself. Contained in injectable formulations, this ester derivative permits the intravenous administration of higher doses of prednisolone than otherwise possible.

When injected the prednisolone hemisuccinate is broken down in the body (the ester is hydrolysed) resulting in the release of prednisolone, the active corticosteroid molecule.

Prednisolone hemisuccinate is therefore not only an ester derivative but also a pro-drug of prednisolone. A pro-drug is defined as a precursor of a drug molecule that results in the formation of the drug (in this case prednisolone).

The hydrolysis of prednisolone hemisuccinate is not immediate. This ester derivative can be detected in both blood and urine for a period of at least 24 hours following the intravenous administration of a normal dose of a prednisolone hemisuccinate preparation (such as Solu delta Cortef).

As described in Rule 73.4, pro-drugs of prohibited substances and metabolites of prohibited substances are also prohibited substances. The administration of injected prednisolone hemisuccinate can therefore result in positive declarations on prednisolone hemisuccinate and/or prednisolone and/or known metabolites of prednisolone.