Which long-acting injectable is not a decanoate formulation?

Which long-acting injectable is not a decanoate formulation?

• A. Olanzapine pamoate
• B. Fluphenazine decanoate
• C. Haloperidol decanoate
• D. Flupenthixol decanoate

Answer: (A)

Depot formulations release their medicine over time, and the name “decanoate” signals a specific type of long-acting ester that creates a lipid-rich depot in muscle. Decanoate esters are made by attaching decanoic acid to the drug, which makes the compound very lipophilic and slow to dissolve, giving a prolonged effect. Olanzapine pamoate is not a decanoate ester; it’s the pamoate salt form of olanzapine. This salt uses pamoic acid rather than a decanoic acid moiety, so its long-acting release mechanism is different from decanoate esters. The other choices—fluphenazine decanoate, haloperidol decanoate, and flupenthixol decanoate—are all decanoate formulations, designed specifically for depot release. So the correct choice is olanzapine pamoate because it is not a decanoate formulation.

Depot formulations release their medicine over time, and the name “decanoate” signals a specific type of long-acting ester that creates a lipid-rich depot in muscle. Decanoate esters are made by attaching decanoic acid to the drug, which makes the compound very lipophilic and slow to dissolve, giving a prolonged effect.

Olanzapine pamoate is not a decanoate ester; it’s the pamoate salt form of olanzapine. This salt uses pamoic acid rather than a decanoic acid moiety, so its long-acting release mechanism is different from decanoate esters. The other choices—fluphenazine decanoate, haloperidol decanoate, and flupenthixol decanoate—are all decanoate formulations, designed specifically for depot release.

So the correct choice is olanzapine pamoate because it is not a decanoate formulation.