Pentostatin is a purine nucleoside analogue and potent inhibitor of the enzyme adenosine deaminase (ADA). It is also known as 2'-Deoxycoformycin and is used as an antineoplastic pharmaceutical ingredient. Pentostatin has been developed for the treatment of hematological malignancies, particularly hairy cell leukemia. The pharmaceutical drug substance is a defined stereochemical compound with the molecular formula C11H16N4O4 and molecular weight 268.27 g/mol.
Pentostatin is a specialized oncology API belonging to the purine analogue class. Its pharmacological activity is associated with inhibition of adenosine deaminase, an enzyme involved in purine metabolism. Because ADA activity is particularly important in lymphoid cells, inhibition of this enzyme can affect lymphocyte survival and proliferation.
The CAS Number of Pentostatin is 53910-25-1. PubChem reports the molecular formula as C11H16N4O4 and molecular weight as 268.27 g/mol. Pentostatin has four defined stereocenters, reflecting its specific three-dimensional molecular configuration.
Pentostatin is described as a white to off-white solid and is freely soluble in distilled water. The marketed injectable formulation is supplied as a sterile, apyrogenic, lyophilized powder.
Pentostatin acts as a potent transition-state inhibitor of adenosine deaminase. ADA is involved in the metabolism of adenosine and deoxyadenosine. Inhibition of ADA results in accumulation of deoxyadenosine metabolites, contributing to toxic effects on lymphoid cells.
This mechanism makes Pentostatin particularly relevant to pharmaceutical development involving hematological cancers. The drug has historically been used as a single-agent treatment for adult patients with hairy cell leukemia.
Pentostatin is a specialized pharmaceutical compound originally isolated from fermentation cultures of Streptomyces antibioticus. Commercial pharmaceutical manufacturing requires controlled processes to achieve consistent chemical identity, stereochemical purity, assay, impurity profile and residual solvent control.
As an oncology API, Pentostatin requires strict quality control throughout manufacturing and packaging. Important quality attributes include identification, assay, related substances, water or moisture control, elemental impurities, residual solvents and stereochemical integrity.
Analytical testing of Pentostatin can include chromatographic identification and assay, impurity profiling, water determination, residual-solvent analysis and appropriate physicochemical characterization. Because the molecule contains defined stereochemistry, stereochemical integrity is an important quality consideration.
The commercially marketed injectable product is formulated as a lyophilized preparation. The official product information reports a final reconstituted product pH range of approximately 7.0–8.5 for the US product, while the UK product information reports 7.0–8.2 for its reconstituted solution. These values apply to the drug product rather than constituting a universal 1% API specification.
Pentostatin is primarily associated with oncology applications. Its established pharmaceutical use includes treatment of hairy cell leukemia, and it has also been investigated in other lymphoid malignancies because of its potent ADA-inhibitory activity.
Pentostatin API is therefore relevant to pharmaceutical companies, oncology formulation developers, research organizations and manufacturers requiring high-quality purine analogue drug substances.
High-quality Pentostatin API should meet appropriate requirements for identity, assay, impurity control, stereochemical integrity and residual process-related impurities. Numerical acceptance criteria should be taken from the applicable approved specification or current pharmacopoeial standard rather than being assumed from the finished injectable product.
For this reason, parameters for which no authoritative universal API acceptance value was verified are identified below as Specification-dependent or N/A, rather than using unsupported numerical values.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 5.0% |
| Residue on Ignition | NMT 0.1% |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 1.0% |
| Water Content | NMT 0.5% |