IONTOPHORESIS

definition of iontophoresis,route of iontophoresis
mechanism action of iontophoresis its merits and demerits

1. IONTOPHORESIS Presented by Rasika.Walunj Modern College Of Pharmacy (For Ladies), Moshi, Pune. 412105 .

2. Definition Introduction of Ions Into The Body Using Direct Electrical Current Transports Ions Across A Membrane Or Into a Tissue Facilitated movement of ions across a skin (membrane) under the influence of an externally applied small electrical potential difference

3. Route Of Intophoresis

4. Mechanism The basic principle of Iontophoretic drug delivery is that “like charges” repel “like charges” so the drug ions are repelled or pushed into the underlying tissue. When direct (DC) current is applied to an ionized drug solution, the ions that have the same charge as the electrode are repelled by the electrode and are delivered through the skin. Sweat ducts are primary paths by which ions move through the skin

5. …..Continue A negatively charged drug delivery electrode transports (repels or pushes) the negative drug ions into the underlying tissue A positively charged drug delivery electrode transports positive drug ions into the skin.

6. …..Continue Transport of drugs across the skin involves either diffusion, migration or electro osmosis. Electro osmosis is the bulk flow of fluid occurring in the same direction as the flow of counter ions when a voltage difference is applied across a charged, porous membrane. This flow involves motion of fluid without concentration gradient and is a significant factor affecting iontophoresis

7. Factors Affecting Iontophoretic Delivery of the Drug Operational Factors : Biological Factors I. Composition of formulation: Concentration of drug solution pH of donor solution: determines the ionization of peptides Ionic strength: increase in ionic strength will decrease drug delivery, as extraneous ions compete with the drug ions.

8. …..CONTINUE Presence of co-ions: generally more mobile and smaller in size than the drug ions itself and can dominate the penetration into the skin thereby causing a decrease in transdermal flux of the drug e.g. buffer II. Physicochemical properties of the permeant : Molecular size and weight : smaller ions are transported at a faster rate than larger ions Polarity: the compounds which are hydrophilic are considered ideal candidates for optimum flux

9. ..Continue Charge: the sign of the charge determines the mechanism by which iontophoresis will proceed e.g., electro-repulsion or electro-repulsion and electro-osmosis . The transport of cations has been shown to be better than anions for amino acids and peptides ,an increase in charge will require pH to be decreased, which in turn shall directly decrease the electroosmosis and electrotransport process. An increased positive charge on peptide, cause it to bind tightly to the membrane creating a reservoir which in turn can decrease the rate at which the steady state flux will be achieved

10. …Continue Experimental conditions: Current density Current profile Duration of treatment Electrode material Polarity of electrodes Biological Factors I. Intra and inter subject variability II. Regional blood flow III. Skin pH IV. Condition of skin

11. MERITS Of IDDS Indicated to introduce ions into the body using direct current follows faradays law of currant. Advantages are it’s painless, Sterile /noninvasive For administration of charged drug Better compliance Small quantity of drug Sports therapist /physiotherapist choice

12. DEMERITS O f IDDS Skin irritation Some time problem of failure of battery Electrode may fails due to corrosion Selection of appropriate ion form drug Not easy to use/Special direction and skilled person Some problem of antigenisity /allergy. Sensitivity to chemical environment Itching Skin pigmentation Skin resistance is always less than The initial value when current of 0.16ma Is applied for 10 sec.

13. Clinical applications Analgesia Scar modification Wound healing Edema Burns Inflammatory MS conditions CA++ deposits Hyperhidrosis M spasm Fungi open skin lesions Herpes Gout

14. THANK YOU….