Naftidrofuryl Oxalate API is a pharmaceutical active ingredient belonging to the vasodilator class. It is the hydrogen oxalate salt of naftidrofuryl and is also known as Naftidrofuryl Hydrogen Oxalate or Nafronyl Oxalate. It is associated primarily with the management of peripheral vascular disorders and is an established pharmaceutical ingredient.
Naftidrofuryl Oxalate has the molecular formula C₂₄H₃₃NO₃ · C₂H₂O₄ and a molecular weight of 473.56 g/mol. Its CAS number is 3200-06-4. The British Pharmacopoeia reference standard catalogue also identifies CAS 3200-06-4 for Naftidrofuryl Oxalate.
Naftidrofuryl Oxalate consists of the naftidrofuryl moiety associated with oxalic acid in a hydrogen oxalate salt form. The chemical structure incorporates a naphthalene ring, tetrahydrofuran ring and diethylaminoethyl ester functionality. The BP describes the substance as a mixture of four stereoisomers.
Naftidrofuryl is used in the management of peripheral and cerebral vascular disorders and is classified as a vasodilator. It has also been described as having activity associated with improving cellular oxidative capacity and as a possible 5-HT₂ receptor antagonist.
Naftidrofuryl has pharmacological activity associated with 5-HT₂ receptor antagonism and effects on cellular metabolism. Its pharmacological profile is associated with vascular smooth-muscle effects and improved cellular oxidative processes, supporting its application in peripheral vascular disorders.
The BP 2025 monograph describes Naftidrofuryl Oxalate as a white or almost white powder. It is freely soluble in water, freely soluble or soluble in ethanol (96%), and slightly or sparingly soluble in acetone.
Naftidrofuryl Oxalate has a dedicated British Pharmacopoeia / European Pharmacopoeia monograph. The BP 2025 monograph specifies a content requirement of 99.0% to 101.0% calculated on the dried substance.
Identification is performed using infrared absorption spectrophotometry together with a test demonstrating the presence of the oxalate component. These tests provide confirmation of the chemical identity of the pharmaceutical substance.
Related substances are controlled by chromatographic testing. The BP monograph identifies specified impurities A, B, C, D, E and F and establishes individual and total impurity limits. Impurities D, E and F have individual limits of 0.10%, 0.20% and 0.20% respectively, while any other impurity is limited to 0.10% and the total impurity limit is 0.50%.
Because the BP defines Naftidrofuryl Oxalate as a mixture of four stereoisomers, stereochemical composition is an important quality attribute. The BP chromatographic procedure requires the first-eluting naftidrofuryl diastereoisomer to represent not less than 30% of the combined area of the two relevant naftidrofuryl peaks.
The BP monograph specifies loss on drying not more than 0.5%, determined by drying the substance at 105°C. This test provides control over moisture and volatile content in the API.
Naftidrofuryl Oxalate has a BP requirement for sulfated ash of not more than 0.1%. This parameter helps control inorganic residue remaining after the prescribed ignition procedure.
The BP monograph specifies an absorbance maximum of 0.1 at 430 nm under the prescribed test conditions. This provides an additional quality-control parameter for the pharmaceutical substance.
The BP assay is performed by potentiometric titration with 0.1 M perchloric acid in anhydrous acetic acid. The monograph states that 1 mL of 0.1 M perchloric acid is equivalent to 47.36 mg of C₂₆H₃₅NO₇.
Naftidrofuryl Oxalate API is relevant to pharmaceutical development involving vascular medicines, vasodilator formulations and peripheral vascular disorder treatments. Its established pharmacopoeial monograph provides defined analytical procedures for identity, purity, assay and other quality attributes.
For commercial pharmaceutical applications, Naftidrofuryl Oxalate should be evaluated against the applicable current pharmacopoeial requirements and the manufacturer's approved specification. The BP is an authoritative collection of standards for pharmaceutical substances and medicinal products, and its monographs define official analytical requirements where applicable.
Naftidrofuryl Oxalate should be stored according to the applicable manufacturer's validated stability data, packaging requirements and approved API specification. Specific commercial storage conditions should be confirmed from the current Certificate of Analysis, specification and stability documentation.
| Parameter | Specification |
|---|---|
| Appearance | White crystalline powder or crystals |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 0.5% |
| Residue on Ignition | NMT 0.1% |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 1.0% |
| Water Content | NMT 0.5% |