Method and apparatus for controlled environment electrotransport

• US 5,591,124 A
• Filed: 05/26/1995
• Issued: 01/07/1997
• Est. Priority Date: 03/30/1990
• Status: Expired due to Term

• Current Assignee: ALZA Corporation (Johnson & Johnson)
• Original Assignee: ALZA Corporation (Johnson & Johnson)
• Inventors: Phipps, Joseph B.
• Primary Examiner(s): Green, Randall L.
• Assistant Examiner(s): SMITH, CHALIN A
• Application Number:
  US08/452,403
• Time in Patent Office: 592 Days
• Field of Search: 604/20, 128/793, 128/799, 128/802, 128/803, 128/788
• US Class Current: 604/20
• CPC Class Codes: A61N 1/0436 Material of the electrode
• CPC Class Codes: A61N 1/044 Shape of the electrode
• CPC Class Codes: A61N 1/0444 Membrane
• CPC Class Codes: A61N 1/0448 Drug reservoir

Abstract

Methods for conducting controlled environment electrotransport are described. The methods generally concern control of the ionic environment of the active electrode reservoir, in an electrotransport system. This control may be utilized, for example, to maintain a constant extraneous ion presence, such as pH. It may also be applied in a preferred manner to maintain selected control over the delivery rate of a target species, in time, in the presence of extraneous ions. Apparatus usable to provide for controlled environment electrotransport are also described. In general the apparatus comprises an electrotransport system including an active electrode reservoir having therein both a primary electrode arrangement and a secondary electrode arrangement, with a control arrangement for selected operation of both. The secondary electrode arrangement, being operated different from the primary electrode arrangement, is selected for operation to selectively enhance or otherwise modify ion presence in the active electrode reservoir, to achieve application of the general methods described. The apparatus may include a sensor means therein, for use as feedback to a control system during operation. Methods and systems involving diffusion type delivery are also described.

Claims

1. A method of controlling delivery of a species, having a polar form and a less polar form, from a reservoir;

said method comprising the steps of;

(a) providing first and second electrode arrangements in electrically conductive contact with the reservoir;

(b) providing as a source of the species a target material;

(c) selectively operating the first and second electrodes to control pH of the reservoir in a manner obtaining selected relative concentrations of the polar and less polar forms of the species, to obtain selected delivery; and

,

(d) selectively operating the electrode arrangements at termination of the delivery process to render excess target material therein in an inactive form.

2. A method of controlling delivery of a species, having a polar form and a less polar form, from a reservoir;

said method comprising the steps of;

(a) providing first and second electrode arrangements in electrically conductive contact with the reservoir;

(b) providing as the species a material having a predrug form and a drug form;

a first one of said predrug form and said drug form being a polar form, and a second one of said predrug form and said drug form being a less polar form; and

,

(c) selectively operating the electrode arrangements to selectively convert the species from the predrug form to the drug form, for delivery.

3. A method of controlling delivery of a species, having a polar form and a less polar form, from a reservoir;

said method comprising the steps of;

(a) providing first and second electrode arrangements in electrically conductive contact with the reservoir;

(b) selectively operating the first and second electrode arrangements to control pH of the reservoir in a manner obtaining selected relative concentrations of the polar and less polar forms of the species, to obtain selected delivery;

said step of selectively operating including;

(i) selectively operating the primary electrode arrangement to provide electromotive force to transport ions from the reservoir; and

,

(ii) selectively operating the secondary electrode arrangement in a manner different from the primary electrode arrangement, to selectively effect relative concentrations of ions in the reservoir.

4. A method of controlling delivery of a species, having a polar form and a less polar form, from a reservoir;

said method comprising the steps of;

(a) providing first and second electrode arrangements in electrically conductive contact with the reservoir;

(b) selectively operating the first and second electrode arrangements to control pH of the reservoir in a manner obtaining selected relative concentrations of the polar and less polar forms of the species, to obtain selected delivery;

said step of selectively operating including;

(i) operating the first electrode arrangement as an anode; and

,

(ii) operating the second electrode arrangement as an anode.

5. A method of controlling delivery of a species, having a polar form and a less polar form, from a reservoir;

said method comprising the steps of;

(a) providing first and second electrode arrangements in electrically conductive contact with the reservoir;

(b) selectively operating the first and second electrode arrangements to control pH of the reservoir in a manner obtaining selected relative concentrations of the polar and less polar forms of the species, to obtain selected delivery;

said step of selectively operating including;

(i) maintaining a constant delivery rate of target ion throughout the delivery process, by generating a selected pH.