Dogs administered approximately 2 mg/kg codeine phosphate PO had similar acetaminophen and morphine pharmacokinetics, produced higher concentrations of codeine-6-glucuronide, and lower concentrations of codeine compared to CYP2D6 poor metabolizer humans. The detailed solvatomorphism study of codeine phosphate sesquihydrate – an important narcotic analgesic and antitusic active pharmaceutical ingredient (API) is reported. Codeine is a naturally occurring phenanthrene alkaloid and opioid agonist with analgesic, antidiarrheal and antitussive activities. Codeine mimics the actions of endogenous opioids by binding to the opioid receptors at many sites within the central nervous system (CNS). acid in its free form and Codeine Phosphate is a base in its free form) may not be as water soluble as their salt forms and it is possible that one or both of these agents could precipitate out of solution. Codeine is a narcotic (opioid) drug used to relieve mild to moderately severe pain. Since codeine is a narcotic that is addictive and can cause serious side effects such as respiratory or cardiac arrest, and shock, which can lead to death. Dosages of codeine are tailored to each patient's needs. Polarity is a question of degree, at neutral pH it is not much ionized, but in alkaline pH it is much more ionized and therefore more soluble and more polar. Anonymous · 1 decade ago 1 PLASMA CODEINE/MORPHINE BY HPLC/DUAL ECD 299 dead volume, which maintained high resolution for the detection of codeine and ethylmorphine in the second cell. Paracetamol has a very low solubility in nonpolar and chlorinated hydrocarbons such as toluene and carbon tetrachloride whereas the solubility is very high in solvents of medium polarity such as N,N-dimethylformamide, dimethyl sulfoxide, and diethylamine. Codeine phosphate forms three hydrates and two anhydrates. The sesquihydrate and hemihydrate, which differ by one water molecule, are stable at room temperature. Stable, but light sensitive. Combustible. Incompatible with strong oxidizing agents, bromides,iodides, heavy metal salts. Oxford University Chemical Safety Data (No longer updated) More details.