Neostigmine is a synthetic reversible acetylcholinesterase inhibitor used as an active pharmaceutical ingredient in medicines that increase acetylcholine activity at neuromuscular junctions. It belongs to the carbamate cholinesterase inhibitor class and is commonly used in pharmaceutical formulations, particularly in hospital and perioperative medicine.
Neostigmine is commonly used in the form of neostigmine methylsulfate, a water-soluble pharmaceutical salt.
Neostigmine is a specialized pharmaceutical API used for the development and manufacture of formulations for reversal of non-depolarizing neuromuscular blockade and other clinically established cholinergic applications.
Important quality attributes include identity, assay, related substances, water content, residue on ignition, pH, residual solvents and elemental impurities, depending on the applicable API specification and salt form.
CAS Number: 59-99-4
Molecular Formula: C12H19N2O2+ · CH3SO4−
Molecular Weight: 334.39 g/mol
Chemical Name: 3-[(Hydroxy(dimethyl)amino)carbonyl]-1-methylpyridinium methyl sulfate
Drug Class: Acetylcholinesterase Inhibitor
Therapeutic Class: Cholinergic Agent
Therapeutic Area: Anesthesiology / Neurology
Molecule Type: Synthetic Small Molecule
Common Pharmaceutical Form: Neostigmine Methylsulfate
Neostigmine is a reversible inhibitor of acetylcholinesterase, the enzyme responsible for hydrolyzing acetylcholine.
Its pharmacological activity includes:
By increasing acetylcholine at the neuromuscular junction, Neostigmine helps restore neuromuscular transmission after administration of non-depolarizing neuromuscular blocking agents.
Neostigmine API is used in pharmaceutical formulations for:
Neostigmine methylsulfate is a water-soluble pharmaceutical salt. Because Neostigmine is commonly supplied as its methylsulfate salt, the physical and analytical properties should be evaluated against the specific pharmaceutical grade and applicable specification.
A controlled manufacturing process for Neostigmine API may involve:
Typical Neostigmine API testing may include:
Store Neostigmine API in a tightly closed container under controlled pharmaceutical storage conditions, protected from excessive moisture, heat and direct light. The final storage conditions should follow validated stability data and the applicable manufacturer specification.
Neostigmine is relevant to research involving:
| Parameter | Specification |
|---|---|
| Appearance | White crystalline powder or crystals |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.5% |
| Heavy Metals | NMT 20 ppm |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 1.0% |
| Water Content | NMT 1.0% |
| Melting Point | Approximately 143–144°C (decomposition) |
| Solubility | Freely soluble in water |