A sensitive enzymic assay for benzylpenicillin.

Area of Science:

• Analytical Chemistry
• Biochemistry
• Pharmaceutical Analysis

Background:

• Accurate quantification of antibiotics like sodium benzylpenicillin is crucial for pharmaceutical quality control.
• Existing methods may lack specificity or require complex procedures for benzylpenicillin determination.

Purpose of the Study:

• To develop a sensitive and specific method for determining sodium benzylpenicillin concentrations.
• To utilize the enzymatic release of 6-aminopenicillanic acid and its reaction with fluorescamine for quantification.

Main Methods:

• Sodium benzylpenicillin was treated with penicillin acylase to release 6-aminopenicillanic acid.
• The released 6-aminopenicillanic acid was quantified via its reaction with fluorescamine at pH 4.
• Fluorescence properties of 6-aminopenicillanic acid and its open beta-lactam ring form were analyzed across different pH levels.

Main Results:

• A linear relationship was observed for sodium benzylpenicillin concentrations between 3.3-33 micrograms/ml.
• 7-Aminocephalosporanic acid exhibited a similar reaction trend to 6-aminopenicillanic acid at pH 4.
• Differential fluorescence responses at pH 7.8 allowed for the estimation of 6-aminopenicillanic acid and its open beta-lactam form in mixtures.

Conclusions:

• The developed fluorescamine-based method provides a reliable means for sodium benzylpenicillin quantification.
• The method's ability to differentiate between 6-aminopenicillanic acid and its degradation product enhances its applicability.
• This technique offers a valuable tool for pharmaceutical analysis, particularly in assessing benzylpenicillin purity and stability.