Dibenzoxepine derivatives

Dibenzoxepine derivatives

Doxepin (Doxedep, Doxetar, Doxtin)

Synthesis

Properties and uses: It is a white or almost white crystalline powder, freely soluble in water, in alcohol, and in methylene chloride. One of the two carbon atoms of the ethylene bridge of the antidepressant may be replaced by oxygen. The side chain of amitriptyline can be attached resulting in the formation of doxepin. Used for the treatment of mild-to-moderate endogeneous depression, Doxepin is a mixture of cis and trans isomers with cis isomer being more active. The drug is a NE and 5-HT uptake blocker, used as monoamine reuptake inhibitor and as tricyclic antidepressant.

Assay: Dissolve the substance in a mixture of anhydrous acetic acid and acetic anhydride and titrate with 0.1 M perchloric acid until the colour changes from blue to green by using crystal violet as an indicator.

Storage: It should be stored in well-closed airtight containers and protected from light.

Dose: The usual dose is 75–150 mg/day by oral or oral liquid.

Dosage forms: Doxepin HCl capsules I.P., Doxepin capsules B.P.