Niraparib Tosylate Monohydrate API Suppliers & Bulk Manufacturers

Available Forms: API (drug substance)

Available Strengths: Supplied to an in-house or pharmacopoeial specification

Reference Brands: Zejula

Category: Active Pharmaceutical Ingredient

Niraparib tosylate monohydrate is the oral PARP inhibitor salt used in ovarian and prostate cancer medicines. It is sourced by oncology formulators, CDMOs and R&D teams.

Product Description:

Niraparib is an oral PARP inhibitor: it blocks enzymes that repair single-strand DNA breaks, which is especially damaging to tumour cells that already have faulty repair pathways, such as those with BRCA mutations. In the US it is approved as maintenance treatment for adults with advanced epithelial ovarian, fallopian tube or primary peritoneal cancer in response to platinum chemotherapy, within the HRD-positive and germline BRCA-mutated groups defined in the label (reference brand: Zejula). It is also approved in a fixed-dose combination with abiraterone acetate for BRCA-mutated metastatic castration-resistant prostate cancer.

Specification at a glance

Regulatory files and timing

The FDA list of Drug Master Files (third quarter 2026) shows 8 active Type II API DMFs for this molecule. Few filings usually means few qualified sources, so early contact with suppliers pays off. For Europe, ask whether the supplier holds a CEP or an EU ASMF and, for imports into the EU, a written confirmation.

Generic or biosimilar entry. United States: Patent expiry; entry not confirmed (Apr 2029 (earliest DS patent)). European Union: No confirmed date.

Handling and quality points

Niraparib is a potent oncology API and is normally made and handled under high-potency controls with a defined occupational exposure band. The commercial salt is a specific crystalline tosylate monohydrate, so check that the supplier controls hydrate state and polymorph by XRPD and water content. The piperidine ring carries a secondary amine, which makes a nitrosamine risk assessment (including the nitroso derivative of the drug itself) a sensible request, along with control of alkyl tosylate impurities.

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Brand names are trademarks of their respective owners and identify the reference medicine only. Information is general and was checked in October 2026; confirm specifications and filings with the supplier before purchase.