Fosaprepitant Dimeglumine

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Cat Number

API265121048

CAS Number

265121-04-8

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Product Detail Description Scientific Support Customer Q&A

CAS Number

265121-04-8

EINECS

682-419-4

Storage

Store at 2-8°C

Synonyms

Fosaprepitant meglumine; Ivemend; MK-0517; FOCINVEZ; D35FM8T64X; CHEBI:64311; DTXSID50181095

Molecular Formula

C37H56F7N6O16P

Molecular Weight

1004.8

Smiles

C[C@H](C1=CC(=CC(=C1)C(F)(F)F)C(F)(F)F)O[C@@H]2[C@@H](N(CCO2)CC3=NN(C(=O)N3)P(=O)(O)O)C4=CC=C(C=C4)F.CNC[C@@H]([C@H]([C@@H]([C@@H](CO)O)O)O)O.CNC[C@@H]([C@H]([C@@H]([C@@H](CO)O)O)O)O

Appearance

White to off-white amorphous powder

General Description

Fosaprepitant dimeglumine is a water-soluble phosphoryl prodrug of aprepitant, a neurokinin-1 (NK1) receptor antagonist. The molecule contains a phosphoryl group attached to the morpholine ring of aprepitant, which dramatically increases aqueous solubility.

Mechanism of Action

Fosaprepitant itself has no pharmacological activity; it is rapidly converted to aprepitant by ubiquitous phosphatases in the plasma. Aprepitant then selectively and competitively blocks NK1 receptors in the central nervous system, preventing substance P binding. Substance P is a key neurotransmitter in the emetic pathway, particularly in the late phase of chemotherapy-induced nausea. This antagonism complements 5-HT3 and corticosteroid mechanisms.

Application

Fosaprepitant is indicated for the prevention of acute and delayed nausea and vomiting associated with highly emetogenic chemotherapy, including cisplatin-based regimens. It is used in combination with a 5-HT3 antagonist and dexamethasone.

In a prospective randomized trial (patients receiving 3‑day cisplatin‑based chemotherapy), fosaprepitant plus triple therapy (neurokinin‑1 antagonist + 5‑HT₃ antagonist + dexamethasone) achieved higher total protection (no vomiting and no rescue medication) during the overall phase (56.9% vs. 40.4%, P=0.018) and delayed phase (57.8% vs. 40.4%, P=0.012) than triple therapy alone, but not during the acute phase. Fosaprepitant also delayed the first vomiting episode. Adding fosaprepitant to triple therapy improves control of chemotherapy‑induced nausea and vomiting, especially in the delayed phase.

Fig. 1 The CONSORT flow chart. (Wang L, et al., 2025)

References

Wang L, et al. Fosaprepitant for the prevention of multiple-day cisplatin chemotherapy-induced nausea and vomiting: a prospective randomized controlled study. BMC Pharmacol Toxicol. 2025;26(1):126.

Does Fosaprepitant Dimeglumine require refrigerated storage as a prodrug?

Yes, it must be stored at 2-8°C. The phosphate ester is thermally labile; at room temperature, rapid enzymatic and chemical hydrolysis to aprepitant occurs.

Is Fosaprepitant Dimeglumine sensitive to light and moisture?

Yes, it is both photosensitive and hygroscopic. Store in original, tightly sealed, light-resistant containers with desiccant under refrigeration.

What is the stability of Fosaprepitant Dimeglumine after reconstitution for intravenous infusion?

Reconstituted solutions are stable for up to 24 hours under refrigeration and 6 hours at room temperature when protected from light.

How is the impurity aprepitant (the active moiety and hydrolysis product) monitored?

This primary degradation product is specifically quantified using a stability-indicating HPLC method, ensuring it remains within ICH limits.