Method and device for detection of bioavailable drug concentration in a fluid sample

A drug delivery device comprising,

• a body comprising a first lumen;
• a securing body comprising a second lumen;
• a flexible circuit comprising a connection end and a sensor end, wherein the flexible circuit comprises a flexible strip of material;
• the sensor end comprising an electrochemical sensor, wherein the electrochemical sensor comprises an array of electrodes;
• wherein the body resides within the second lumen of the securing body, wherein an upper surface of the flexible circuit is adjacent and conforms to an interior circumferential curvature of the second lumen, wherein a lower surface of the flexible circuit is adjacent and conforms to an exterior circumferential curvature of the body;
• the securing body comprising at least one opening positioned above the array of electrodes, wherein the at least one opening exposes the array of electrodes to a fluid sample;
• a control system that receives an output of the electrochemical sensor upon detection of a bioavailable drug concentration in the fluid sample and controls delivery of a bioavailable drug into a patient based on the bioavailable drug concentration.

A method of modulating drug delivery comprising:

• placing a sensor device into a blood vessel of a patient, the sensor device including a body, a securing body, and a flexible circuit, wherein the body comprises a first lumen, wherein the securing body comprises a second lumen, wherein the flexible circuit comprises an electrochemical sensor, wherein the electrochemical sensor comprises an array of electrodes, wherein the array of electrodes comprises a water-immiscible coating surrounding the array of electrodes, wherein the body resides within the second lumen of the securing body, wherein an upper surface of the flexible circuit is adjacent and conforms to an interior circumferential curvature of the second lumen, wherein a lower surface of the flexible circuit is adjacent and conforms to an exterior circumferential curvature of the body, wherein the securing body comprises at least one opening positioned above the array of electrodes;
• the placing the sensor device into the blood vessel including the at least one opening exposing a fluid sample containing a bioavailable hydrophobic drug to the array of electrodes, wherein the coating of the array of electrodes partitions the bioavailable hydrophobic drug from the fluid sample;
• detecting an oxidation/reduction current within the coating during said exposing, wherein the detected current relates to a concentration of the bioavailable hydrophobic drug in the fluid sample;
• and
• modulating delivery of a hydrophobic drug into the patient based on the concentration of the bioavailale hydrophobic drug in the fluid sample.

A method comprising,

• exposing a fluid sample to an electrochemical, voltammetric sensor device, wherein the electrochemical, voltammetric sensor device comprises,
• a body comprising a lumen;
• a securing body comprising a second lumen;
• a flexible circuit comprising a connection end and a sensor end, wherein the flexible circuit comprise a flexible strip of material;
• the connection end comprising a plurality of vias;
• the sensor end comprising an electrochemical sensor, wherein the electrochemical sensor comprises an array of electrodes, wherein the array of electrodes are electrically connected to the vias using conductive traces, wherein the array of electrodes comprises a water-immiscible coating that surrounds the array of electrodes, wherein the coating partitions a hydrophobic drug from the fluid sample;
• wherein the body resides within the second lumen of the securing body, wherein an upper surface of the flexible circuit is adjacent and conforms to an interior circumferential curvature of the second lumen, wherein a lower surface of the flexible circuit is adjacent and conforms to an exterior circumferential curvature of the body;
• the securing body comprising at least one opening positioned above the array of electrodes;
• the exposing the fluid sample to the electrochemical, voltammetric sensor device including the at least one opening exposing the array of electrodes to the fluid sample;
• detecting an oxidation/reduction current within the coating during said exposing, wherein the detected current depends on a concentration of the hydrophobic drug in the coating as a consequence of the partitioning of the hydrophobic drug from the fluid sample, wherein the detected current correlates to the concentration of the hydrophobic drug in the fluid sample.

An electrochemical, voltammetric sensor device comprising:

• a body comprising a first lumen;
• a securing body comprising a second lumen;
• a flexible circuit comprising a connection end and a sensor end, wherein the flexible circuit comprises a flexible strip of material;
• the sensor end comprising an electrochemical sensor, wherein the electrochemical sensor comprises two or more electrodes and a coating that surrounds the two or more electrodes, wherein the coating comprises a structural component, a water immiscible organic solvent, a charge transfer component, and an electrochemically active, hydrophobic drug, wherein the sensor device measures an oxidation/reduction current within the coating using the two or more electrodes, wherein the measured oxidation/reduction current correlates to the amount of the electrochemically active, hydrophobic drug partitioned into the coating from a fluid sample during use of the sensor device;
• wherein the body resides within the second lumen of the securing body, wherein an upper surface of the flexible circuit is adjacent and conforms to an interior circumferential curvature of the second lumen, wherein a lower surface of the flexible circuit is adjacent and conforms to an exterior circumferential curvature of the body;
• the securing body comprising at least one opening positioned above the two or more electrodes, wherein at least one opening exposes the two or more electrodes to the fluid sample.

An electrochemical, voltammetric sensor device comprising,

• a body comprising a first lumen;
• a securing body comprising a second lumen;
• a flexible circuit comprising a connection end and a sensor end, wherein the flexible circuit comprises a flexible strip of material;
• the sensor end comprising an electrochemical sensor, wherein the electrochemical sensor comprises at least two electrodes and a water-immiscible coating that surrounds the at least two electrodes, wherein the coating is in contact with the at least two electrodes, wherein the coating comprises about 15 to about 67 wt percent PVC, about 33 to about 85 wt percent 0-NPOE, and about 0.001 to about 15 wt percent TDATPFPB, wherein the coating partitions a hydrophobic drug from a fluid sample, wherein the partitioned drug is oxidized within the coating, wherein the at least two electrodes measure an oxidation/reduction current within the coating, and wherein the measured oxidation/reduction current indicates the concentration of the hydrophobic drug in the fluid sample;
• wherein the body resides within the second lumen of the securing body, wherein an upper surface of the flexible circuit is adjacent and conforms to an interior circumferential curvature of the second lumen, wherein a lower surface of the flexible circuit is adjacent and conforms to an exterior circumferential curvature of the body;
• the securing body comprising at least one opening positioned above the at least two electrodes, wherein the at least one opening exposes the at least two electrodes to the fluid sample.

An electrochemical, voltammetric sensor device comprising

• a body comprising a first lumen;
• a securing body comprising a second lumen;
• a flexible circuit comprising a connection end and a sensor end, wherein the flexible circuit comprise a flexible strip of material;
• the sensor end comprising an electrochemical sensor, wherein the electrochemical sensor comprises electrodes and a water-immiscible coating that surrounds the electrodes, wherein the coating comprises about 15 to about 67 wt percent PVC, about 33 to about 85 wt percent o-NPOE, and about 0.001 to about 15 wt percent TDATPFPB, wherein the coating partitions a hydrophobic drug from a fluid sample;
• wherein the body resides within the second lumen of the securing body, wherein an upper surface of the flexible circuit is adjacent and conforms to an interior circumferential curvature of the second lumen, wherein a lower surface of the flexible circuit is adjacent and conforms to an exterior circumferential curvature of the body;
• the securing body comprising at least one opening positioned above the electrodes, wherein at least one opening exposes the electrodes to the fluid sample.