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P. MADRIGAL Y COLS. AN. R. ACAD. NAC. FARM.

Stability of cefotaxime

The decrease rate constants of the concentration of free cefotaxi-
me in rats with vanadium and in rats without it are of first-order,
according to the best values of correlation coefficient. The absolute
values of the logarithmic of the observed constants K are shown in
Table IV, where the highest value of log K is in heart in the 2 groups
of rats, therefore the cefotaxime is more stable in heart than in the
others studied organs.

TABLE IV. The absolute values of the logarithmic of the observed constant K

Rats without vanadium Rats with vanadium

BLOOD 1.73 1.73

LIVER 2.16 1.79

SPLEEN 1.93 1.93

KIDNEY 1.93 1.85

LUNG 1.86 1.85

HEART 2.16 2.03

In rats without vanadium the stability of cefotaxime in organs is
decreasing in the sense: heart and liver > kidney and spleen > lung.
In rats with vanadium the stability is: heart > kidney > liver, spleen
and lung.

In blood it was observed the lowest stability of cefotaxime in the
2 groups of rats.

Therefore in rats that have been or not intoxicated with vanadium
the highest and less stability is at the same site.

It is not only important the presence of vanadium in the
concentration, distribution and stability of cefotaxime, but also the
presence of the metal results to be crucial in the activity of this
cephalosporin because of the decrease of the free cefotaxime
concentration due to the metal.

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