Chemical Properties
Yellow, hygroscopic powder.
Uses
Labelled Lymecycline. A semi-synthetic antibiotic related to Tetracycline (T291400). Antibacterial.
Definition
ChEBI: A tetracycline-based broad-spectrum antibiotic. It is approximately 5000 times more soluble than tetracycline base and is unique amongst tetracyclines in that it is absorbed by the "active transport" process across the intestinal wall.
Originator
Armyl,Armour Pharm.
Manufacturing Process
Amido-N-(lysinomethyl)tetracycline hydrochloride:
To 18.3 g of L-lysine hydrochloride dissolved in 100 ml of water is added 10
ml of 37% aqueous solution of formaldehyde. To the resultant mixture is
added 44.0 g of anhydrous tetracycline dissolved in 500 ml of tetrahydrofuran.
After thorough mixing the product forms over a period of about 15 min as an
oily layer which after separation from the aqueous phase is added dropwise to
3 L of stirred isopropyl alcohol. The product after recovery by filtration, is
reslurried with acetone, filtered and dried at 65°C at reduced pressure.
The product thus obtained has a bioassay of 500 mcg/mg (K. pneumonlae
oxytetracyoline assay).
Therapeutic Function
Antibiotic
Pharmaceutical Applications
2-N-lysinomethyl-tetracycline. A water-soluble prodrug of
tetracycline available for oral administration.
Its antimicrobial activity is due to the tetracycline content. It
is lipophilic, rapidly absorbed from the gastrointestinal tract and
widely distributed. Concentrations around 1 mg/kg have been
found in maxillary sinus tissue some 3 h after administration
of a conventional dose. The half-life is 7–14 h. Approximately
30% of an orally administered dose is excreted as active drug in
the urine, where it achieves concentrations of 300 mg/L.
Its untoward effects and clinical uses are those of tetracycline,
although it is claimed to be better tolerated.
Clinical Use
Antibacterial agent:
Also used for treatment of acne
Drug interactions
Molecular weight (daltons) 602.6
% Protein binding Approx 25-60
% Excreted unchanged in urine 25
Volume of distribution (L/kg) Approx 1.3-1.7
Half-life - normal/ESRF (hrs) 10 / Increased
Metabolism
The tetracyclines are excreted in the urine and in the
faeces. Renal clearance is by glomerular filtration.
Up to 60% of an intravenous dose, and up to 55% of an
oral dose, is eliminated unchanged in the urine. Usually
between 40% and 70% of a dose is excreted in the urine;
urinary excretion is increased if urine is alkalinised.
