Page 52 - phytochemistry II -pharmD general
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mouth, by IM, subcutaneous, IV injection and injection into the space around
the spinal cord, or rectally
• Maximum effect is reached after about 20 minutes when given intravenously
and after 60 minutes when given by mouth, while duration of effect is 3 –
7 hours.
• Toxicity: Minimum lethal dose is 200 mg, addicts tolerate higher doses .
Codeine
Properties ≠ morphine
- Codeine is the methyl ether of morphine,
- Codeine differs from morphine in its solubility behavior, being soluble in water,
ether, benzene, chloroform, in ethanol.
- It does not form phenates with alkalies (as it is non phenolic) and gives no colour
with ferric chloride.
However it remains dissolved in aqueous phase after alkalinization, with either
fixed alkalis or ammonia, as the alkaloid base is water soluble
Assay: By non aqueous titration
Uses: Codeine is used to relief dry initiating cough.
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