This document discusses a drug delivery system using microchips. It describes how microchips can be fabricated to contain multiple reservoirs for storing drugs in solid, liquid, or gel form. The reservoirs are sealed with conductive membranes that can be dissolved electrically to release the drugs at controlled times. This allows for pulsed or continuous drug release over weeks or years to improve patient compliance. Microchips offer advantages over traditional delivery methods but also have limitations such as being non-refillable and requiring explantation.

1. Drug Delivery System
by
Microchip Technology
BY:
Gebremariam Birhanu (Ph.D.)

2. Outline
• Objectives
• Introduction
• Components of microchip
• Micro fabrication
• Mechanism of drug release
• Advantages
• Disadvantages
• Summary

3. Objectives
• After success full completion of this session you will
be able:-
Define what drug delivery mean
Explain what microchip mean
Discuss how the drug is loaded & release for the microchip
Create a microchip delivery platform for various drugs
Apply microchip drug delivery system for the treatment of various problems

4. Introduction
Definition
Drug delivery system is the:-
Approaches
Formulations
Technologies and
Systems for transporting a pharmaceutical compound in the body as needed to
safely achieve its desired therapeutic effect.
Very important aspect of medical treatment

5. Introduction
Drug delivery system is the:-
The effectiveness of drug directly related to the way in which drugs are
administered
• Can make it very difficult to select the proper drug delivery system
Some therapies require that the drug be repeatedly administered to the patient
over a long period of time, or in specific amounts at a time in order to maximize
drug effectiveness.

6. Problems with most Methods of Drug Delivery
In many cases, patients often forget, are unwilling, or are
unable to take their medication
Some drugs too potent for systemic drug delivery (intravenous)
& may cause more harm than good

7. Introduction
Definition
Microchips are drug delivery devices which are capable of controlled,
pulsatile or continuous release of wide variety of drugs after safely
implanted into some part of the body.
A microchip can storage of one or more drugs inside in any form (solid,
liquid, or gel), with the release of the compounds achieved on demand &
with no moving parts.
Simple to use and manufacture
biocompatible and small enough to be implantable in the human body

8. Device design
 The microchip delivery system consists of a substrate containing multiple reservoirs which
are capable of holding chemicals in the liquid, solid or gel form.
 The substrate is; strong, non-degradable, etcheble, impermeable to the delivered
chemicals & non-degradable to the surrounding environment within the body
 Each reservoir in the substrate is capped with a conductive membrane & wired with the
final circuitry controlled by a microprocessor.
 The central processor should be able to control electrically the exact time of release & the
amount of drugs dispersed by controlling the dissolution of the membrane.
 Delivery of drugs for weeks or years at a time
 Varying dosages—should release substances in a controlled dependable manner

10. Device design
 The design of the release system depends on the treatment of required
by the patient
 Continuous or pulsed release.
 It can be achieved by a passive or active release system.
 In the passive system, the drugs diffuse through a membrane or enter
the body by the degradation of the substrate.
 In the active systems are triggered by a microprocessor & they are
preferred due to a more predictable release profile.
 The exact time release & amounts of drugs can then be controlled.

11. Reservoir caps
 It consists of anodes surrounded by cathodes.
 The portion of the anode directly above the reservoir oxidizes & dissolve into
solution upon the application of a potential b/n the cathode & anode.
 This exposes the release system to the surrounding fluids & results in the
release of the molecules or drugs.
 The membrane material should remain stable in the solution in the absence
of an applied electric potential to prevent premature release of the chemical
from the microchip.

12. Reservoir caps
 The membrane material should also be able to dissolve quickly &
selectively when specific electric potential is applied.
 Gold is chosen as the membrane material b/se it can;
 Easily deposited
 Inert &
 Resist corrosion in many solutions over large pH range
 Optimum anode potential is needed in order to release the chemicals from
the reservoir.

13. Control circuitry and power source
 The control circuitry consists of a timer, demultiplexer, microprocessor or an
input source.
 The microprocessor will control the desired reservoir to be activated so that a
variety of drugs may be contained in each specific reservoir.
 The input source can either be a memory source, remote control device or a
biosensor.
 A thin-film micro-battery can be used as a power source.
 All of these can be patterned directly onto the device.

14. Working of microchips
 It consists of anode and cathode.
 Any number of anode & cathodes can be included on a microchip,& they can be
of any shape or size to suit the electrode design.
 Each reservoir is filled with a compound to be released.
 Open ends of the reservoirs are sealed with a Waterproof material .
 An electrical voltage is applied b/n the anode & cathode to desired reservoir .
 Lithium rechargeable batteries are used.

15. Working of microchips
 The anode membrane dissolves due to an electrochemical reaction.
 This reservoir is now open, allowing the material inside to diffuse out into
the surrounding fluid
 Each reservoir on the microchip can be activated & opened individually.
 Each reservoir can be activated individually b/se each anode has its own
independent connection to the power source
 As the number of reservoirs on a microchip becomes large, it should be
possible to connect each anode to the power supply through a
demultiplexer.
 The demultiplexer serves as a "routing station" by directing power to a
particular reservoir based on a code sent to the demultiplexer by a micro-
processor or remote control.

16. Working of microchips

17. Examples
 Doctors in Denmark used the microchips for women with osteoporosis &
they implanted it under the skin for 20 days.
 This devices released a dose of drug at a specific time each day,
replacing the daily hormone injections currently used to manage the
disorder.
 This implant remove the inconvenience of regular injections.
 It is used in diabetes, Parkinson’s disease, CHF, anti coagulation.

18. Advantages & disadvantages of Microchips Drug Delivery
• Advantages
 It is simple to use and manufacture.
 useful for psychiatric and elderly patients who rely on a complicated regime of drugs and are at
risk if they miss a dose or take it at a wrong time .
 It is multi-welled; drugs and other molecules can be delivered for weeks or years at a time.
 It can hold many different of varying dosages and can release these substances in a controlled
dependable manner.
 Potential for local delivery
 Simplicity of release mechanism
 Accuracy

19. Advantages & disadvantages …
• Disadvantages
Not refillable without explanted.
Required skill about technology.
Required explants
Cost

20. Summary
• Microchip for drug delivery system is a potential system that allows the storage and
dependable, controlled release of multiple drugs.
• This device is less complex and much more dependable than the devices that attempt to
control drug release rate .
• The microchip can be created by general microfabrication techniques and can also be self-
contained, which eliminates the need for patient or doctor intervention.
• The proposed device described can last over a year; however, the delivery abilities do depend
on patients need.
• So there is no second thought to the fact that these delivery system holds a lot of potential
and offers an area which should be explored.