Benzylpenicillin Penicillin analysis

In 1929, Fleming discovered that the mould Penicillium notatum inhibits the growth of bacteria. In 1941 Florey and Chain succeeded in isolating the active agent, known as penicillin, in the form of its sodium salt. The structural elucidation was achieved by chemical degradation and was confirmed in 1945 by X-ray analysis of penicillin G (benzylpenicillin). The structures were shown to be (3/S,5i ,6/ )-6-(acylamino)-2,2-dimethyl-7-oxopenam-3-carboxylic acids ... 

The X-ray diffraction analysis of the sodium, potassium and the rubidium salts of the benzylpenicillin showed the presenee of a -lactam ring, thereby fmlher supporting the faet that structure (IV) is the probable structure of penicillin. 

The amounts of penicilloylated proteins in commercial benzylpenicillin and semisynthetic penicillins seem to vary considerably. Whereas up to 200-300 parts/ 10 of penicilloy 1-protein in benzylpenicillin preparations were reported by Batchelor et al. (1967) and also by Butcher and Stewart (1970), other groups have only detected less than 10 parts/10 of proteinaceous impurities in commercial benzylpenicillin (Dursch 1968 Preud homme and Lunel 1969 Weidenmuller and Ziegler 1970 Walsh et al. 1971 Ottens et al. 1971 Vilim et al. 1976). As described by Ottens et al. (1971), the methods used for the determinations, i.e., dialysis, membrane filtration, and gel filtration followed by penicilloyl and protein analysis, have several drawbacks. Penicillin degradation products and polymers were found to influence the determinations, making these somewhat unreliable. 

We also present a quantitative determination in solid binary mixtures of three penicillin antibiotics benzylpenicillin, bacampicillin, and amoxicillin. The method appears to be unique, contrasting with the known vibrational approaches in solution, where the Raman method has been used. In the solid state, some penicillin antibiotics give a broad fluorescence band, which overlaps the Raman peaks and limits its application for quantitative analysis in solid state. Using our... 

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