Diphenhydramine is a first generation antihistamine that exhibits anti-tussive, antiemetic, sedative, anti-allergic, and anticholinergic activities. Diphenhydramine inhibits muscarinic acetylcholine receptors (mAChRs) and Na+ channels and acts as an inverse agonist at histamine H1 receptors. In vivo, diphenhydramine decreases leukocyte infiltration into injury sites.
| Cas No. | 147-24-0 |
|---|---|
| Purity | ≥98% |
| Formula | C17H21NO • HCl |
| Formula Wt. | 291.82 |
| Chemical Name | 2-Diphenylmethoxy-N,N-dimthylethanamine hydrochloride |
| IUPAC Name | 2-benzhydryloxy-N,N-dimethylethanamine;hydrochloride |
| Synonym | Alledryl; Amidryl; Benadryl; Dihydral; Dolestan; Halbmond; Noctomin; Syntedril |
| Melting Point | 166-170°C |
| Solubility | Soluble in acetone (20 mg/mL), water (1 g/mL), and alcohol (500 mg/mL). Slightly soluble in benzene or ether. |
| Appearance | White crystalline powder |
| Store Temp | Ambient |
|---|---|
| Ship Temp | Ambient |
| MSDS | D3462 MSDS PDF |
|---|---|
| Info Sheet | D3462 Info Sheet PDF |
Raphael GD, Angello JT, Wu MM, et al. Efficacy of diphenhydramine vs desloratadine and placebo in patients with moderate-to-severe seasonal allergic rhinitis. Ann Allergy Asthma Immunol. 2006 Apr;96(4):606-14. PMID: 16680933.
Yamashiro K, Kiryu J, Tsujikawa A, et al. Suppressive effects of histamine H1 receptor antagonist diphenhydramine on the leukocyte infiltration during endotoxin-induced uveitis. Exp Eye Res. 2001 Jul;73(1):69-80. PMID: 11428864.
Kim YS, Shin YK, Lee C, et al. Block of sodium currents in rat dorsal root ganglion neurons by diphenhydramine. Brain Res. 2000 Oct 27;881(2):190-8. PMID: 11036158.
Reiner PB, Kamondi A. Mechanisms of antihistamine-induced sedation in the human brain: H1 receptor activation reduces a background leakage potassium current. Neuroscience. 1994 Apr;59(3):579-88. PMID: 8008209.
