Эритромицин химические свойства, назначение, производство
Описание
Erythromycin ethyl succinate is a mixed double ester pro-drug in which one carboxyl of succinic acid
esterifies the C-2′ hydroxyl of erythromycin and the other ethanol. This pro-drug frequently is
used in an oral suspension for pediatric use largely to mask the bitter taste of the drug. Film-coated tablets
also are used to deal with this. Some cholestatic jaundice is associated with the use of EES.
Химические свойства
White to off white crystalline powder
Использование
Erythromycin A is a 14-membered macrocyclic lactone with broad spectrum antibiotic activity, isolated from Saccharopolyspora erythraea (formerly Streptomyces erythreus) in 1952. Erythromycin is one of only a handful of microbial metabolites to have profoundly shaped the treatment of bacterial disease in the last 50 years. Erythromycin has given rise to new generations of semi-synthetic derivatives with improved stability and potency. Our product has been HPLC-purified to remove contaminants and degradation products.
Определение
An antibiotic produced by growth of Streptomyces
erythreus Waksman. It is effective against infections caused by Gram-positive bacteria, including
some β-hemolytic streptococci, pneumococci, and
staphylococci.
Показания
Erythromycin is an antibiotic in the macrolide family
that also has promotility effects because
it is a motilin agonist.
Антимикробная активность
Gram-positive rods, including Clostridium spp. (MIC50 0.1–1 mg/L), C. diphtheriae (MIC50 0.1–1 mg/L), L. monocytogenes (MIC50 0.1–0.3 mg/L) and Bacillus anthracis (MIC50 0.5–1.0 mg/L), are generally susceptible. Most strains of M. scrofulaceum and M. kansasii are susceptible (MIC50 0.5–2 mg/L), but M. intracellulare is often and M. fortuitum regularly resistant. Nocardia isolates are resistant. H. ducreyi, B. pertussis (MIC50 0.03–0.25 mg/L), some Brucella, Flavobacterium, Legionella (MIC50 0.1–0.5 mg/L) and Pasteurella spp. are susceptible. H. pylori (MIC 0.06–0.25 mg/L) and C. jejuni are usually susceptible, but C. coli may be resistant. Most anaerobic bacteria, including Actinomyces and Arachnia spp., are susceptible or moderately so, but B. fragilis and Fusobacterium spp. are resistant. T. pallidum and Borrelia spp. are susceptible, as are Chlamydia spp. (MIC ≤0.25 mg/L), M. pneumoniae and Rickettsia spp. M. hominis and Ureaplasma spp. are resistant.
Enterobacteriaceae are usually resistant. Activity rises with increasing pH up to 8.5. Incubation in 5–6% CO2 raises the MIC for H. influenzae from 0.5–8 to 4–32 mg/L; MICs for Str. pneumoniae and Str. pyogenes also rise steeply. Activity is predominantly bacteristatic.
Приобретенная устойчивость
In Europe, the USA and other countries the incidence of resistance in Str. pneumoniae ranges from 5% to over 60%. In Str. pneumoniae strains resistant or intermediately susceptible to penicillin G, resistance rates above 80% have been reported. Increasing rates of resistance in clinical isolates of Str. pyogenes have also been reported, threatening its use as an alternative to penicillin G in allergic patients.
Lower rates of resistance have been reported in other bacterial species, including methicillin-resistant Staph. aureus, coagulase-negative staphylococci, Str. agalactiae, Lancefield group C and G streptococci, viridans group streptococci, H. pylori, T. pallidum, C. diphtheriae and N. gonorrhoeae.
Фармацевтические приложения
A natural antibiotic produced as a complex of six components (A–F) by Saccharopolyspora erythraea. Only erythromycin A has been developed for clinical use. It is available in a large number of forms for oral administration: the base compound (enteric- or film-coated to prevent destruction by gastric acidity); 2′-propionate and 2′-ethylsuccinate esters; a stearate salt; estolate and acistrate salts of 2′-esters. The 2′-esters and their salts have improved pharmacokinetic and pharmaceutical properties and are less bitter than erythromycin. It is also formulated as the lactobionate and gluceptate forparenteral use.
Биологическая активность
Erythromycin is the principal one in antimicrobial drugs. Although available as the parent entity, semisynthetic derivatives have proved to be clinically superior to the natural cogener. Like the tetracyclines, synthetic transformations in the macrolide series have not significantly altered their antibacterial spectra, but have improved the pharmacodynamic properties. For example, the propionate ester of erythromycin lauryl sulfate (erythromycin estolate) has shown greater acid stability than the unesterified parent substance. Although the estolate appears in the blood somewhat more slowly, the peak serum levels reached are higher and persist longer than other forms of the drug. However, cholestatic hepatitis may occasionally follow administration of the estolate and, for that reason, the stearate is often preferred. Erythromycin is effective against Group A and other nonenterococcal streptococci, Corynebacterium diphtheriae, Legionella pneumophila, Chlamydia trachomatis, Mycoplasma pneumoniae, and Flavobacterium. Because of the extensive use of erythromycin in hospitals, a number of Staph. aureus strains have become highly resistant to the drug. For this reason, erythromycin has been used in combination with chloramphenicol. This combination is also used in the treatment of severe sepsis when etiology is unknown and patient is allergic to penicillin.
Механизм действия
Macrolides are inhibitors of protein synthesis at the ribosomes. They impair the elongation cycle of the
peptidyl chain by specifically binding to the 50S subunit of the
ribosome. Specificity toward prokaryotes relies upon the absence of
50S ribosomes in eukaryotes. The main interaction site is located at
the central loop of the domain V of the 23S rRNA, at the vicinity
of the peptidyl transferase center. The macrolide binding site is located
at the entrance of the exit tunnel used by the nascent peptide chain to
escape from the ribosome, at the place where the central loop of
domain V interacts with proteins L4 and L22 and with the loop of
754 Macrolides and Ketolides
hairpin 35 in domain II of rRNA.
Interaction occurs via the formation of hydrogen-bonds between the
reactive groups (2u-OH) of the desosamine sugar and the lactone ring and adenine residue 2058. This explains why
mutation or methylation in position 2058 as well as mutations in proteins
L4 and L22 confer resistance to macrolides. The binding site of macrolides on the ribosome overlaps that of chloramphenicol or lincosamides
such as clindamycin, explaining pharmacologic
antagonism between these antibiotic classes as well as cross-resistance.
Фармаколо?гия
Erythromycin inhibits bacterial protein synthesis by reversibly binding with their 50
S ribosomal subunit, thus blocking the formation of new peptide bonds. Erythromycin is
classified as a bacteriostatic antibiotic.
However, it can also exhibit a bactericidal effect against a few types of microbes at certain concentrations.
Bacterial resistance to erythromycin can originate by two possible mechanisms: the
inability of reaching the cell membrane, which is particularly relevant in the case of the
microorganisms Enterobacteriaceae, or in the case of the presence of a methylated alanine
in the 23 S ribosomal RNA of the 50 S subunit, which lowers the affinity of erythromycin to it.
Erythromycin acts on Gram-positive (staphylococci both produced and not produced by
penicillinase, streptococci, pneumococci, clostridia) and a few Gram-negative microorganisms (gonococci, brucelli, hemophile and whooping cough bacilli, legionelli), mycoplasma,
chlamydia, spirochaeta, and Rickettsia. Colon and blue-pus bacilli, as well as the bacilli
shigella, salmonella, and others are resistant to erythromycin.
Клиническое использование
Erythromycin is used (offlabel
indication) to accelerate gastric emptying in diabetic
gastroparesis and postoperative gastroparesis.
Tachyphylaxis will occur, so it cannot be used uninterruptedly
for long periods.
Профиль безопасности
Poison by intravenous
and intramuscular routes. Moderately toxic by ingestion, intraperitoneal, and
subcutaneous routes. An experimental
teratogen. Other experimental reproductive
effects. Mutation data reported. When
heated to decomposition it emits toxic
fumes of NOx.
Методы очистки
It recrystallises from H2O to form hydrated crystals which melt at ca 135-140o, resolidifies and melts again at 190-193o. The melting point after drying at 56o/8mm is that of the anhydrous material and is at 137-140o. Its solubility in H2O is ~2mg/mL. The hydrochloride has m 170o, 173o (from aqueous EtOH, EtOH/Et2O). [Flynn et al. J Am Chem Soc 76 3121 1954, constitution: Wiley et al. J Am Chem Soc 79 6062 1957]. [Beilstein 18/10 V 398.]
Эритромицин препаратная продукция и сырье
сырьё
препарат