anhydrous ampicillin

Cornelius Krasel krasel at
Tue Nov 4 04:36:47 EST 1997

colossus... <s535290 at> wrote:
> I just got some anhydrous ampicillin to test the minimum inhibitory
> concentrations of some bugs, but I was told to make a salt using some 
> NaOH in order to dissolve it. Are there any of you who have ever had to
> do this ?  I wasn't even told how concentrated the NaOH should be, or what
> amounts to use. I've used the regular ampicillin which just dissolves in
> water but this anhydrous stuff is the one that one is supposed to use when
> testing MICs. It just doesn't dissolve like the regular stuff does.

I've never done this, but it doesn't make sense to me. Basically, the
"normal" ampicillin is the Na-salt of the "anhydrous" one. Therefore,
correcting for the additional Na should do the trick with the "normal"


/* Cornelius Krasel, U Wuerzburg, Dept. of Pharmacology, Versbacher Str. 9 */
/* D-97078 Wuerzburg, Germany   email: phak004 at  SP4 */
/* "Science is the game we play with God to find out what His rules are."  */

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