Title: Difenoxin
CAS Registry Number: 28782-42-5
CAS Name: 1-(3-Cyano-3,3-diphenylpropyl)-4-phenyl-4-piperidinecarboxylic acid
Additional Names: 1-(3-cyano-3,3-diphenylpropyl)-4-phenylisonipecotic acid; difenoxilic acid; difenoxylic acid
Manufacturers' Codes: McN-JR-15403-11
Trademarks: Lyspafen (Cilag-Chemie)
Molecular Formula: C28H28N2O2
Molecular Weight: 424.53
Percent Composition: C 79.22%, H 6.65%, N 6.60%, O 7.54%
Literature References: Active metabolite of diphenoxylate, q.v., from which it may be prepared by hydrolysis of the ethyl ester: W. Soudijn, I. van Wijngaarden, DE 1953342; eidem, US 3646207 (1970, 1972 to Janssen). Series of articles on pharmacology, toxicology, metabolism: Arzneim.-Forsch. 22, 513-531 (1972). Toxicity data: Niemegeers et al., ibid. 516.
Derivative Type: Hydrochloride
Manufacturers' Codes: R-15403
Molecular Formula: C28H28N2O2.HCl
Molecular Weight: 461.00
Percent Composition: C 72.95%, H 6.34%, N 6.08%, O 6.94%, Cl 7.69%
Properties: White amorphous power, mp 290°. Very slightly sol in water (0.023%); sparingly sol in chloroform, tetrahydrofuran, dimethylacetamide, DMSO. Stable, can be stored for several years under normal conditions; not hygroscopic; not affected by light. LD50 orally in rats: 149 mg/kg (Niemegeers).
Melting point: mp 290°
Toxicity data: LD50 orally in rats: 149 mg/kg (Niemegeers)
NOTE: This is a controlled substance (opiate): 21 CFR, 1308.11.
Therap-Cat: Antiperistaltic; antidiarrheal.
Keywords: Antidiarrheal.
Difenpiramide Difenzoquat Difethialone Diflorasone Difloxacin

Systematic (IUPAC) name
1-(3-cyano-3,3-diphenylpropyl)-4-phenylpiperidine-4-carboxylic acid
Clinical data
AHFS/Drugs.com International Drug Names
Legal status Controlled (S8) (AU) Schedule I (by itself); Schedule IV (with atropine) (US)
CAS number 35607-36-4 N
ATC code A07DA04
PubChem CID 34328
DrugBank DB01501
ChemSpider 31620 YesY
KEGG D03809 YesY
Synonyms Difenoxin, Motofen
Chemical data
Formula C28H28N2O2 
Mol. mass 424.53 g/mol
 N (what is this?)  (verify)

Difenoxin (Motofen, R-15403) is a 4-phenylpiperidine derivative that is related to the opioid analgesic drug pethidine (meperidine) and more distantly related to alphaprodine and piritramide, and it is an active metabolite of the anti-diarrhoea drug diphenoxylate. Difenoxin et al. have a high peripheral/central actions ratio, working primarily on various opioid receptors in the intestines.[1] Difenoxin was developed in 1970 in Belgium at Janssen Pharmaceutica.