Tianeptine sodium

Tianeptine sodium is the sodium salt form of Tianeptine. It is the most common form of Tianeptine. It is water soluble. It is highly orally bioavailable, and is absorbed rapidly if ingested, leading to an immediate sharp rise in Tianeptine concentrations in the body / no sustained absorption so rapid tailoff. The sodium salt form is (usually) very hygroscopic, and if in the form of a raw powder, the sodium salt turns to goo when exposed to atmospheric humidity.

Tianeptine free acid is Tianeptine itself, not a salt of Tianeptine. This form is not water soluble. Unpublished research suggests Tianeptine free acid is a bit less orally bioavailable than Tianeptine sodium, but would have the benefit of being absorbed more gradually – and thus would lead to a gentle rise in Tianeptine concentrations in the body, with sustained absorption for several hours – if consumed p.o. The free acid form is non hygroscopic and will not turn to goo if left exposed to the atmosphere.

Tianeptine free acid shares some properties with Tianeptine sulfate hemihydrate. Both are forms of Tianeptine that are non hygroscopic, much less soluble in water – and due to reduced solubility, appear to have sustained release characteristics.

Pharmacokinetic data is available for Tianeptine sodium salt, both in humans and in animal models. In contrast, pharmacokinetic data (absorption, distribution parameters, oral bioavailability, etc), do not appear to have been published, either for Tianeptine free acid or for Tianeptine sulfate. Overall oral bioavailability may vary between forms (factors such as particle size, polymorph, etc also play roles here). The molecular masses also vary for each of the forms.