How can I avoid decreasing solubility while increasing ph?

Question

How can I avoid decreasing solubility while increasing ph?

I have a drug that is soluble in water, when increasing the pH, it breaks down and becomes insoluble (formulates a cloudy white solution), the pH was 3-4 and I need it at pH 7, the drug is ciprofloxacin hydrochloride, can i avoid decreasing solubility while increasing ph?

Thanks all

Answer 1

The best way to attempt this is to dissolve the drug in a small volume of acid (as small a volume as possible), and then dilute to a final volume using a buffer at pH 7 (sodium phosphate buffer; NaH₂PO₄/Na₂HPO₄).  If that doesn't work, and you are actually using this in an experiment in the lab (and not just doing a homework exercise), you can try dissolving it in DMSO and then diluting it in buffer, or dissolve it in some other solvent (ethanol, etc.) with final dilution in buffer.  Of course, if you do the latter, you'll need to run appropriate vehicle controls in your experiment.