This application claims priority from Korean Patent Application No. 2004-50429, filed on Jun. 30, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a method of purifying highly pure vancomycin HCl from a fermentation broth of a microorganism.
2. Description of the Related Art
Vancomycin is one of the glycopeptide antibiotics and produced by microorganisms of the genus Actinomycetes, such as the strain Amycolatopsis orientalis (ATCC 19795). Vancomycin exhibits a strong inhibition effect on gram positive bacteria, such as Streptococci, Staphylococci, Clostridium difficile, and gram positive bacteria resistant to penicillin and cephalosporin antibiotics. Also, vancomycin is known to have high treatment effects on diseases derived from methicillin-resistant Staphylococcus aureus (MRSA) which is fatal to post-operation, elderly patients, and persons having weak immunity. Vancomycin HCl is generally consumed as solution orally or in capsule form, or it is injected.
According to European Pharmacopeia, vancomycin be at least 93% pure and have impurities composing not more than 4% of the solution.
Conventional methods of purifying vancomycin are described in U.S. Pat. Nos. 4,440,753, 4,845,194, 5,037,652, 5,149,784, 5,235,037, 5,258,495, 5,574,135 etc. In order to increase a yield of vancomycin, in these methods, the fermentation broth is adjusted to a pH of 11 and filtered, and then the pH of the obtained filtrate is adjusted to 8. Next, the filtrate is passed through an absorbent resin, and then the vancomycin is eluted from the absorbent resin. This operation is repeated two or three times. Subsequently, a basic salt of vancomycin is crystallized with a solvent, and the obtained crystals are acidified. The acidified product is recrystallized with acetone or alcohol to produce vancomycin HCl. The process is very complicated since vancomycin HCl crystals are obtained by adjusting its pH several times, and after obtaining crystals of the basic salt of vancomycin as intermediates, vancomycin HCl are recrystallized. In addition, vancomycin may be unstable at a high pH. Especially, due to a residual colorant, the obtained vancomycin may be reddish in color and it is difficult to obtain vancomycin having a purity of at least 93%. Thus, it is difficult to produce vancomycin which may satisfy a specification prescribed in European Antibiotic Drugs Standards.
The present inventors conducted vigorous research to overcome these problems and discovered a method of producing highly pure vancomycin HCl, which may directly recover vancomycin HCl without a process of obtaining an intermediate, i.e., a basic salt of vancomycin, which is performed due to an increased pH of the product containing vancomycin, thus resulting in a simplified process, and may provide a highly pure vancomycin and especially, eliminate most colorants contained in vancomycin.