Spectrophotometric Methods as Solutions to Pharmaceutical Analysis of p-Lactam Antibiotics

Judyta Cielecka-Pionteki, Przemyslaw Zalewski, Anna Krause and Marek Milewski Poznan University of Medical Sciences, Department of Pharmaceutical Chemistry PozLab Contract Research Organization at Centre of Transfer of Medical Technologies 

The common element of chemical structure of all P-lactam antibiotics is five-membered P-lactam ring. Currently, higher significance in treatment have derivatives in which the P-lactam ring is fused to  

These connections implicate the different intra-ring stress. The presence of sulphur atom and/or double bonds influence on length of bond and intra-molecular angle in molecule of P-lactam analog. Finally for some derivatives, the differences in stability are noticeable. Additionally, the factor distinguishing a stability of derivatives of P-lactam analogs are 

Spectra of (3-lactam antibiotics recorded by using direct spectrophotometry do not have desired selectivity due to the paesenoe of related products. A comparison of sharp zero-order spectra and/ or value of absorption maxima for some (3-lactam analogs with ones obtained for CRS chemical reference substance) is recommended by pharmacopeias for an their identification [7]. Lack of desired absorbing species in chemical structure of penam analog often do not allow to apply direct spectrophotometry even for qualitative studies of substance of high purity. 

Paradoxically, the significant instability of analogs can sometimes solve this problem due to formation of degradation products that can absorb ultraviolet radiation permitting determination of perental substance. 

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Spectrophotometric Methods as Solutions to Pharmaceutical Analysis of P-Lactam Antibiotics... 

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