Tegaserod is a synthetic serotonin 5-HT4 receptor agonist used as a gastrointestinal pharmaceutical active ingredient. The commercially relevant pharmaceutical form is Tegaserod Maleate, a 1:1 salt of tegaserod with maleic acid. Tegaserod maleate has CAS No. 189188-57-6, molecular formula C20H27N5O5, and molecular weight 417.5 g/mol.
Tegaserod was originally developed under the code SDZ HTF 919 / HTF-919 and has been used in the treatment of irritable bowel syndrome with constipation (IBS-C). FDA's regulatory review describes tegaserod as a 5-HT4 receptor agonist that stimulates gastrointestinal motility and intestinal secretion and may reduce visceral sensitivity.
For pharmaceutical API applications, Tegaserod Maleate is generally the relevant material rather than the free-base active moiety. PubChem identifies Tegaserod Maleate as a 1:1 combination of tegaserod and maleic acid. The maleate salt has the molecular formula C20H27N5O5 and molecular weight 417.5 g/mol.
The free tegaserod active moiety has the formula C16H23N5O and molecular weight 301.39 g/mol, with CAS No. 145158-71-0.
Tegaserod is a substituted guanidine derivative containing an indole ring and methoxy substituent. Its IUPAC name is 1-[(E)-(5-methoxy-1H-indol-3-yl)methylideneamino]-2-pentylguanidine. PubChem classifies tegaserod as a guanidine, hydrazine, indole and carboxamidine derivative.
Tegaserod Maleate is formed by combining the basic tegaserod molecule with one equivalent of maleic acid. This salt form provides the pharmaceutical material historically used in Zelnorm and is the appropriate form to identify when a customer specifically requires Tegaserod Maleate API.
Tegaserod acts primarily as a 5-HT4 receptor agonist. Activation of 5-HT4 receptors in the gastrointestinal tract promotes the peristaltic reflex and intestinal secretion and can influence gastrointestinal sensory pathways. FDA's regulatory review specifically describes activation of gastrointestinal 5-HT4 receptors as stimulating peristalsis and intestinal secretion while inhibiting visceral sensitivity.
Tegaserod Maleate API is principally associated with gastrointestinal pharmaceutical formulations for IBS-C.
The FDA's current regulatory history identifies the reintroduction of tegaserod for adult women under 65 years of age with IBS-C, with cardiovascular-risk restrictions incorporated into labeling.
Potential pharmaceutical applications include:
Tegaserod Maleate is a chemically defined small-molecule API and can be evaluated using conventional pharmaceutical analytical techniques including identification, assay, related-substance testing, water determination, residual-solvent testing and inorganic impurity controls.
A publicly available Tegaserod Maleate commercial specification reports 99.0–101.0% assay on an anhydrous basis, loss on drying NMT 2.0%, water NMT 1.0%, heavy metals NMT 10 ppm, residue on ignition NMT 0.1%, unspecified individual impurities NMT 0.10% and total impurities NMT 0.5%. These values are best treated as a published commercial specification, rather than automatically described as current USP official limits.
Tegaserod Maleate API manufacturing requires controlled synthesis of the tegaserod active moiety followed by formation and purification of the maleate salt. Pharmaceutical manufacturing controls should address chemical identity, assay, related substances, residual solvents, water, inorganic residues and microbiological quality where applicable.
The final API should be produced under an appropriate pharmaceutical quality system with validated analytical procedures and controlled starting materials.
| Property | Value |
|---|---|
| API Name | Tegaserod Maleate |
| Active Moiety | Tegaserod |
| CAS No. | 189188-57-6 |
| Active Moiety CAS | 145158-71-0 |
| Molecular Formula | C20H27N5O5 |
| Molecular Weight | 417.5 g/mol |
| Active Moiety Formula | C16H23N5O |
| Active Moiety MW | 301.39 g/mol |
| FDA UNII – Maleate | E5XNT3RF5A |
| FDA UNII – Active Moiety | 458VC51857 |
| Development Code | SDZ HTF 919 / HTF-919 |
| Pharmacological Class | 5-HT4 receptor agonist |
| Physical Form | Powder |
| Reported Melting Point | 155°C for tegaserod free base |
The identity and molecular data are supported by PubChem/FDA records; the 155°C value is reported as an experimental melting point for the free base and should not be confused with a validated API release criterion for the maleate salt.
Tegaserod Maleate API should be packed in suitable pharmaceutical-grade, well-closed containers that protect the material from moisture and environmental contamination. Storage conditions should follow the manufacturer's validated stability data and approved material specification.
Commercial pharmaceutical-grade Tegaserod Maleate API documentation may include:
Tegaserod Maleate requires consistent control of assay, related substances, water, residual solvents and inorganic impurities. A pharmaceutical manufacturing program should use validated HPLC and other appropriate analytical procedures to maintain batch-to-batch consistency.
For pharmaceutical development and commercial applications, Tegaserod Maleate should be supplied according to the customer's required pharmacopoeial, regulatory or internally approved specification.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 99.0–101.0% (anhydrous basis) |
| Loss on Drying | NMT 2.0% |
| Residue on Ignition | NMT 0.1% |
| Heavy Metals | NMT 10 ppm |
| Individual Impurity | NMT 0.10% |
| Total Impurities | NMT 0.5% |
| Water Content | NMT 1.0% |