Racecadotril is a synthetic antidiarrheal active pharmaceutical ingredient and a peripherally acting enkephalinase inhibitor. It reduces intestinal secretion of water and electrolytes without significantly affecting intestinal motility. Racecadotril is identified by CAS 81110-73-8, molecular formula C₂₁H₂₃NO₄S, and molecular weight 385.48 g/mol. FDA GSRS classifies the substance as racemic and confirms the same CAS, formula and molecular weight.
Racecadotril, also known as Acetorphan, is the racemic form of benzyl [[(2RS)-2-[(acetylsulfanyl)methyl]-3-phenylpropanoyl]amino]acetate. It is a neutral endopeptidase/enkephalinase inhibitor and is classified under WHO ATC code A07XA04.
The current BP 2025/Ph. Eur. monograph describes Racecadotril as a white or almost white powder, practically insoluble in water and freely soluble in methanol and methylene chloride. The monograph specifies 98.0–102.0% content calculated on the dried substance.
| Parameter | Details |
|---|---|
| Product Name | Racecadotril |
| Synonym | Acetorphan |
| CAS Number | 81110-73-8 |
| Molecular Formula | C₂₁H₂₃NO₄S |
| Molecular Weight | 385.48 g/mol |
| FDA UNII | 76K53XP4TO |
| PubChem CID | 107751 |
| ChEBI | Racecadotril entry |
| WHO ATC | A07XA04 |
| Chemical Type | N-acyl amino acid derivative |
| Pharmacological Class | Enkephalinase inhibitor |
| Stereochemistry | Racemic (RS) |
| Physical Form | White/almost white powder |
| Therapeutic Area | Gastrointestinal / Antidiarrheal |
FDA GSRS explicitly identifies Racecadotril as racemic with one defined stereocenter and confirms the molecular formula and molecular weight.
Racecadotril is primarily used as an antisecretory antidiarrheal. It inhibits intestinal enkephalinase, thereby reducing the degradation of endogenous enkephalins and decreasing excessive intestinal water and electrolyte secretion.
Pharmaceutical applications include:
Racecadotril has a current accessible BP 2025/Ph. Eur. monograph, making it possible to use considerably more specific CMS specifications.
The pharmacopoeial assay is performed by liquid chromatography, with the content requirement of 98.0–102.0% on the dried substance. Related substances are controlled by LC, with specified impurities C, E and F each limited to 0.20%, impurity A to 0.10%, unspecified impurities individually to 0.10%, and total impurities to 0.50%. Loss on drying is limited to 0.5%, while sulfated ash is limited to 0.1%.
Racecadotril API manufacturing requires controlled synthesis and purification to achieve consistent stereochemical composition, assay and impurity profile. Because the pharmacopoeial substance is specifically defined as the (2RS) form, the manufacturing process should maintain the required racemic composition.
Quality control should include:
Racecadotril should be stored in tightly closed packaging under controlled conditions and protected from excessive heat, moisture and light.
The current TCI analytical reference recommends storage in a cool, dark place below 15°C, while the BP/Ph. Eur. monograph specifies the relevant substance characteristics and quality controls.
Typical Racecadotril API documentation can include:
A reliable Racecadotril API manufacturing program should provide consistent pharmaceutical quality supported by validated chromatographic testing and pharmacopoeial controls. The availability of a BP/Ph. Eur. monograph allows the API to be evaluated against defined assay, related-substance, loss-on-drying and sulfated-ash requirements rather than relying solely on generic commercial purity claims.
| 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 0.10% |
| Heavy Metals | NMT 10 ppm |
| pH (1% Solution) | 5–7 |
| Individual Impurity | NMT 0.10% |
| Total Impurities | NMT 0.50% |
| Melting Point | 89°C |