Pergolide is a semi-synthetic ergot-derived dopamine receptor agonist used as a pharmaceutical active ingredient. It is chemically classified as an ergoline derivative and has activity at both D1 and D2 dopamine receptors. Pergolide is commonly encountered in pharmaceutical development and API applications in the form of Pergolide Mesylate, also known as Pergolide Methanesulfonate or Pergolide Mesilate.
The parent compound Pergolide has the CAS Number 66104-22-1, molecular formula C19H26N2S, and molecular weight 314.5 g/mol. The pharmaceutical mesylate salt has CAS Number 66104-23-2, molecular formula C20H30N2O3S2, and molecular weight 410.6 g/mol.
Pergolide Mesylate is formed as the methanesulfonate salt of pergolide and has historically been the principal pharmaceutical form. The official product information for Permax identifies Pergolide Mesylate as 8β-[(methylthio)methyl]-6-propylergoline monomethanesulfonate and reports a molecular weight of 410.60 g/mol.
Pergolide has potent dopaminergic activity and was historically used as an adjunct to levodopa/carbidopa in the management of Parkinson's disease. However, its regulatory status differs by market. In the United States and Canada, pergolide-containing human products were withdrawn in 2007 because of concerns regarding cardiac valvular dysfunction.
Pergolide is a sulfur-containing ergoline compound with defined stereochemistry. The parent compound contains three defined stereocenters, corresponding to the stereochemical configuration represented in its chemical structure. The molecule contains an indole-containing ergoline framework and a methylthiomethyl substituent.
Pergolide Mesylate has a molecular formula of C20H30N2O3S2 and molecular weight 410.6 g/mol. The mesylate salt is the form most relevant when discussing pharmaceutical Pergolide API.
Pergolide Mesylate intended for pharmaceutical use requires controlled manufacturing and analytical testing. Important quality attributes include identity, assay, related substances, residual solvents, water content, elemental impurities and stereochemical integrity.
For API manufacturing, analytical methods should be appropriately validated for the intended specification. Chromatographic testing can be used for assay and related-substance determination, while spectroscopic techniques can support identity testing. Residual solvents should be evaluated according to applicable ICH requirements.
Current public information does not establish a single universally applicable numerical API specification for every CMS field. Therefore, values such as assay, individual impurities, total impurities, water and residue on ignition should not be invented or transferred from a finished dosage form unless an authoritative API monograph specifically establishes them.
Pergolide is primarily associated with dopaminergic pharmaceutical applications and has historically been used in Parkinson's disease therapy. It acts directly on dopamine receptors and has also been described as suppressing prolactin secretion.
Pergolide Mesylate is also available in certain veterinary pharmaceutical applications. Current DailyMed records include Pergolide Mesylate USP bulk ingredient products intended for veterinary use.
A high-quality Pergolide API should demonstrate consistent chemical identity, assay, impurity profile and stereochemical integrity. Because Pergolide Mesylate is a defined pharmaceutical salt, correct control of the mesylate form and molecular composition is important.
For commercial API production, specifications should be based on the applicable pharmacopoeial standard, approved dossier or validated manufacturer specification. Parameters without a reliably verified universal numerical limit are identified as Specification-dependent or N/A below.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| 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% |
| Water Content | NMT 0.5% |