Antibiotics Pharmaceutical Raw material Cefradine Powder

CAS:38821-53-3

MF:C16H19N3O4S

MW:349.4

EINECS:254-137-8

Specification: 99% min Cefradine Powder

Sample:Cefradine Powder

Packaging:1kg/bag, 25kg/drum

Brand: Henrikang

Appearance: White Powder

Storage: Cool Dry Place

Shelf Life: 2 Years

Test Method: HPLC

Cefradine Powder Usage and Synthesis.

Cefradin has a killing effect on most Gram-positive and negative bacteria, and has good antibacterial effect on penicillinase-free and penicillinase-producing Staphylococcus aureus, Streptococcus epidermidis, Streptococcus pyogenes, Streptococcus pneumoniae, Streptococcus grass-green streptococcus, and slightly poorer activity on Escherichia coli, Escherichia spp. and Klebsiella spp. It has a certain effect on Neisseria gonorrhoeae, and is also active on enzyme-producing gonococcus, and is less active on Haemophilus influenzae. activity against Haemophilus influenzae, and poorer activity against Haemophilus influenzae.

Pseudomonas aeruginosa, drug-resistant Enterobacteriaceae, Mycoplasma fragilis and Mycoplasma and Chlamydia are resistant to it, and the rest of anaerobes are sensitive to it.

Because of its strong antimicrobial power, good clinical efficacy and high safety for various infections, as well as high tolerance to β-lactamase and good pharmacokinetic properties, it is widely used for acute pharyngitis, tonsillitis, otitis media, bronchitis, pneumonia and other respiratory infections caused by cephalosporin-sensitive organisms, urogenital tract infections, and soft tissue skin infections. It is widely used in respiratory infections such as pharyngitis, tonsillitis, otitis media, bronchitis, pneumonia, genitourinary infections and skin and soft tissue infections.

Uses and functions of Cefradine.

Cefradin has the advantage of a low incidence of adverse reactions and is the drug of choice for the treatment of inflammation. It is used for the treatment of acute pharyngitis, tonsillitis, otitis media, bronchitis, pneumonia and other respiratory tract infections caused by sensitive organisms, infections of the genitourinary tract and soft tissue skin infections.

Pharmacological Effect of Cefradine.

Cefradine is a first-generation cephalosporin whose antibacterial action is characterised by:

(1) the antibacterial effect on gram-positive bacteria, including penicillin-sensitive and resistant Staphylococcus aureus (except methicillin-resistant Staphylococcus aureus) is stronger than the second and third generation of cephalosporins; the role of gram-negative bacteria is not as good as that of second-generation cephalosporins, and even worse than that of third-generation cephalosporins.

(2)It is unstable to the β-lactamase produced by gram-negative bacilli, but the stability of β-lactamase produced by Staphylococcus aureus is better than that of the second and third generation cephalosporins.

Cefradin is rapidly absorbed after oral administration, and the absorption of intramuscular injection is poorer than that of oral administration, but the blood concentration is maintained for a longer period of time. Fasting oral 0.5g, 1 hour after the peak blood concentration, about 11 ~ 18μg / ml; intramuscular injection of 0.5g, 1 ~ 2 hours after the peak blood concentration, an average of about 6μg / ml; Intravenous injection of 0.5g, 5 minutes after the blood concentration of 46μg / ml.

The drug is well distributed in tissues and body fluids after absorption. In the myocardium, uterus, lungs, prostate and bone tissue can reach the effective antibacterial concentration, the concentration of the drug in the liver tissue is equal to the blood concentration, and the concentration in the cerebrospinal fluid is only 8-12% of the same period of blood concentration.

The drug can be secreted into breast milk in small quantities, and can also cross the placental barrier into the foetal blood circulation. When 0.5g is taken orally, the concentration in amniotic fluid is about 1～3μg/ml.

Synthetics of  Bulk Cefradine Powder.

The synthetic methods of cephradine mainly include enzyme method and chemical synthesis method, although the enzyme synthesis process is simple, only one step of acylation can be completed, but the yield is low, not suitable for industrial production, so the latter is usually used in industrial production.

There are more reports on the synthesis of cephradine abroad, usually using 7-ADCA as raw material, the C4-position carboxylic acid group is protected, and then condensed with cyclohexadienylglycine after protection of the intermediate, and then hydrolysed to obtain cephradine.

There are two general methods for protecting the C4-position carboxyl group.

One is to use organic bases (tetramethylguanidine (TMG), etc.) to form soluble salts with 7-ADCA;

The second is to use silane-based reagents (such as bis(trimethyl)silourea (BSU), hexamethyldisiloxamine (HMDS), trimethylchlorosilane (TMCS), etc.) to react with 7-ADCA to form silyl esterified 7-ADCA, among the silane-based reagents, BSU is more active but more expensive, and TMCS is cheaper but less active, and HMDS was chosen as the silyl esterification after comprehensive considerations reagent and also added saccharin as a catalyst for the activity of HMDS.

We have studied the conditions of cephradine hydrolysis crystals, under the appropriate conditions, we can get the crystals with high yield and good purity, and we have solved the problem of stormy crystals in the hydrolysis process in the industrial production, and the total yield can be up to 90%.