a-6-deoxy-5-hydroxytetracycline monohydrate; Vibramycin
Doxycycline is a broad-spectrum antibiotic synthetically derived from oxytetracycline. It is a semi-synthetic tetracycline. Doxycycline penetrates the bacterial cell and interferes with the protein biosynthesis, stopping the process. Other microorganisms are also sensitive to the antibiotic activity of Doxycycline, such as Mycoplasma, Chlamydia and Ricketsiae. Resistance to antibiotics of the tetracycline family is primarily due to inhibition of transport of the drug into the cell or by increasing antibiotic efflux. The biological mechanism is mainly through plasmid mediation but it may also occur by chromossomal alteration.
Doxycycline monohyrate is very soluble in fats and oils. It is transported in serum bound to serum lipids and fat globules. It is taken up in oils. It is transported in serum bound to serum lipids and fat globules. It is taken up into tissues by crossing the bilipid cellular membrane. The monohydrate is the base molecule hydrated with one molecule of water. Doxycycline will not degrade into an epianhydro form.
Identification
HPLC: the retention time of doxycycline in the sample solution should be the same as that in the standard solution: Conforms to reference Color reaction with sulfuric acid: Conforms to reference Color reaction with silver nitrate: Conforms to reference
Related Substances
6-Epi-doxycycline: Conforms to reference Methacycline: Conforms to reference Other Impurities: Conforms to reference
Solubility
Doxycycline monohydrate is soluble in ethanol or methanol. It has a high degree of lipid solubility and a low affinity for calcium binding. It is highly stable in normal human serum. It is very slightly soluble in water.