Impedance systems, devices, and methods for evaluating iontophoretic properties of compounds

1. A method for screening candidate drugs for iontophoretic delivery, comprising:

applying an alternating current to a bulk solution comprising at least one drug candidate;

measuring an impedance response of the bulk solution comprising the at least one drug candidate; and

ranking the at least one drug candidate for suitability for iontophoretic delivery based in part on the measured impedance response of the bulk solution comprising the at least one drug candidate.

2. The method according to claim 1 wherein measuring the impedance response of the bulk solution comprising the at least one drug candidate comprises measuring the impedance response at two or more frequencies of the alternating current.

3. The method according to claim 1 wherein measuring the impedance response of the bulk solution comprising the at least one drug candidate comprises obtaining at least one of an amplitude or a phase shift of a response signal at two or more frequencies of the alternating current.

4. The method according to claim 1 , further comprising:

determining a flux value based in part on the measured impedance response of the bulk solution comprising the at least one drug candidate.

5. The method according to claim 1 wherein the bulk solution comprises two or more candidate drugs.

6. The method according to claim 1 , further comprising:

measuring the impedance response of a composition comprising at least one drug candidate through at least one resistive element; and

ranking the composition comprising the at least one drug candidate based in part on the measured impedance response through the at least one resistive element.

7. An assay for determining the iontophoretic deliverability of a pharmaceutical composition, comprising:

applying an alternating current to a bulk solution comprising the pharmaceutical composition;

measuring at least one impedance response of the pharmaceutical composition with an impedance spectrometer;

correlating the at least one measured impedance response to an iontophoretic transport value estimate for the pharmaceutical composition; and

ranking the pharmaceutical composition for iontophoretic deliverability based in part on the iontophoretic transport value estimate.

8. The assay according to claim 7 wherein the pharmaceutical composition comprises at least one candidate drug compound.

9. The assay according to claim 7 wherein measuring the impedance response of the pharmaceutical composition comprises measuring the impedance response at two or more frequencies of the alternating current.

10. The assay according to claim 7 wherein measuring an impedance response of the pharmaceutical composition comprises: obtaining at least one of a magnitude or a phase shift of a response signal for the pharmaceutical composition, with an impedance spectrometer, at two or more frequencies of the alternating current.

11. A method for screening candidate drugs for iontophoretic delivery, comprising:

applying an alternating current to a composition comprising at least one drug candidate a bulk solution;

measuring through at least one resistive element an impedance response of the composition comprising the at least one drug candidate in the bulk solution; and

ranking the composition comprising the at least one drug candidate based in part on the measured impedance response of the composition comprising the at least one drug candidate in the bulk solution.

12. The method according to claim 11 wherein measuring the impedance response of the composition comprising the at least one drug candidate in the bulk solution comprises measuring the impedance response at two or more frequencies of the alternating current.

13. The method according to claim 11 wherein measuring the impedance response of the composition comprising the at least one drug candidate in the bulk solution comprises obtaining at least one of an amplitude or a phase shift of a response signal at two or more frequencies of the alternating current.

14. The method according to claim 11 , further comprising:

determining a flux value based in part on the measured impedance response of the composition comprising the at least one drug candidate in the bulk solution.

15. The method according to claim 11 wherein the composition comprises two or more candidate drugs in the bulk solution.