INTRODUCTION

Dimenhydrinate is an antihistamine drug commonly used to prevent and treat motion sickness, nausea, and vertigo. It is a combination of diphenhydramine and 8-chlorotheophylline, where the latter reduces the sedative effects of diphenhydramine. It is available in tablet, liquid, and injectable forms under various brand names.

MANUFACTURE

The synthesis involves the combination of diphenhydramine and 8-chlorotheophylline in a 1:1 molar ratio, typically forming a stable salt. The mixture is purified and crystallized to produce pharmaceutical grade dimenhydrinate.

SynonymsN-(2-Diphenylmethoxyethyl)-N,N-dimethylammonium 8-chlorotheophyllinate
CAS no.523-87-5
EINECS no.208-350-8
Molecular formulaC17H21NO · C7H7ClN4O2
Molecular weight469.96
Structure

APPLICATIONS

Motion Sickness & Nausea Relief:
Used to prevent and treat nausea, vomiting, and dizziness associated with motion sickness and inner ear disorders.
Vertigo Treatment :
Helps manage vertigo caused by conditions like Meniere’s disease.
Anti-Allergic Uses:
Has antihistamine properties and can be used for mild allergic reactions.
Sleep Aid:
Sometimes used as an over-the-counter sedative due to its drowsiness-inducing effects.
Post-Anesthesia & Chemotherapy Support:
Used to prevent nausea and vomiting in postoperative and chemotherapy patients.

SPECIFICATIONS – USP

TestUnitSpecification
DescriptionWhite, crystalline, odourless powder
SolubilitySlightly soluble in water, freely soluble in Alcohol and in Chloroform. Sparingly soluble in Ether
Identification
(A) IR TestShould conform to USP monograph
B) By HPLC (Dimenhydrinate)Should conform to USP monograph
(C) By HPLC (8-Chlorotheophylline)Should conform to USP monograph
Melting point°C102.0 – 107.0
Loss on Drying%NMT 0.5
Residue on Ignition%NMT 0.3
Organic impurities [By HPLC ]
Theophylline%NMT 0.2
Dimenhydrinate related compound E%NMT 0.15
Diphenhydramine related compound A%NMT 0.2
Any other individual impurity%NMT 0.10
Total impurities%NMT 0.5
Assay by HPLC (On Dried Basis)
Diphenhydramine (C17H21NO)%NLT 53.0 – NMT 55.5
8-Chlorotheophylline (C7H7ClN4O2)%NLT 44.0 – NMT47.0
Residual solvents [By GC]
Isopropyl Alcohol%NMT 0.5
Microbial Limit Test 
Total aerobic bacterial countCfu/g≤ 100.0
Total Yeast & mold countCfu/g≤ 10.0
E. ColiShould be Absent
S. AureusShould be Absent
Salmonella Spp.Should be Absent
P. AeruginosaShould be Absent

PACKING

25 Kg drum

STORAGE

Store in airtight container in a cool, dry place

CERTIFICATIONS

WHO-GMP, EU Written Confirmation

ExSyn offers Dimenhydrinate USP/EP/BP on commercial scales and welcomes enquiries. Our exceptional quality and service will make ExSyn your supplier of choice! If you need any additional information or SDS, please contact us.

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