Neostigmine is a synthetic reversible acetylcholinesterase inhibitor belonging to the parasympathomimetic/cholinesterase inhibitor class. It increases the availability of acetylcholine at cholinergic synapses by inhibiting the enzyme responsible for acetylcholine breakdown.
Neostigmine is commonly formulated as Neostigmine Bromide or Neostigmine Methylsulfate and is used in pharmaceutical applications involving neuromuscular transmission and gastrointestinal and urinary smooth-muscle activity.
Neostigmine is particularly associated with the reversal of non-depolarizing neuromuscular blockade and the management of myasthenia gravis, depending on the pharmaceutical formulation and approved indication.
Neostigmine is a well-characterized cholinesterase inhibitor pharmaceutical API used in pharmaceutical formulation development, analytical testing, neurological research and drug manufacturing.
The API is available in different salt forms. For CMS purposes, the exact salt should always be identified because Neostigmine Bromide and Neostigmine Methylsulfate have different molecular formulas, molecular weights and specifications.
Active Moiety: Neostigmine
Neostigmine CAS Number: 59-99-4
Neostigmine Bromide CAS Number: 114-80-7
Neostigmine Bromide Molecular Formula: C₁₂H₁₉BrN₂O₂
Neostigmine Bromide Molecular Weight: 303.20 g/mol
Chemical Name: 3-[(Dimethylcarbamoyl)oxy]-N,N,N-trimethylanilinium bromide
Drug Class: Cholinesterase Inhibitor
Therapeutic Class: Parasympathomimetic / Anticholinesterase
Therapeutic Area: Neurology / Anesthesiology / Gastroenterology
Molecule Type: Synthetic Small Molecule
The Neostigmine active moiety has a molecular weight of 223.29 g/mol, while the bromide salt has a molecular weight of 303.20 g/mol.
Neostigmine is a reversible acetylcholinesterase inhibitor.
Its pharmacological activity includes:
Neostigmine is a quaternary ammonium compound and does not readily cross the blood-brain barrier.
Neostigmine API is relevant to:
Neostigmine increases acetylcholine availability at the neuromuscular junction by inhibiting acetylcholinesterase.
This pharmacological action can improve neuromuscular transmission and is an important reason for its use in the reversal of non-depolarizing neuromuscular blocking agents in appropriate clinical settings.
Neostigmine has been used as a cholinesterase inhibitor in the management of myasthenia gravis, a condition characterized by impaired neuromuscular transmission.
By reducing acetylcholine breakdown, neostigmine increases acetylcholine availability at the neuromuscular junction and can enhance muscle contraction.
Neostigmine Bromide is described as a white or almost white crystalline powder or colorless crystals. It is hygroscopic.
It is very soluble in water and soluble in ethyl alcohol. Its aqueous solutions are described as neutral to litmus paper.
A controlled Neostigmine API manufacturing process may involve:
Typical Neostigmine Bromide API testing may include:
The British/European pharmacopoeial specification reports an assay range of 98.5–101.0% on the dried substance, loss on drying NMT 1.0%, sulfated ash NMT 0.1%, and sulfates NMT 200 ppm for Neostigmine Bromide.
Store Neostigmine Bromide API in an airtight container protected from light and moisture.
Because the material is hygroscopic, appropriate moisture protection should be maintained throughout storage and handling.
Neostigmine is relevant to research involving:
| Parameter | Specification |
|---|---|
| Appearance | White crystalline powder or crystals |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.5% – 101.0% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.1% |
| Individual Impurity | NMT 0.1% |
| Total Impurities | NMT 0.3% |
| Water Content | NMT 1.0% |