Conventional and novel drug delivery system.

Basic understanding of conventional and novel drug delivery system.

1. CONVENTIONAL AND NOVEL DRUG DELIVERY SYSTEM By: ZILLE ALI Department of Pharmaceutics IIT(BHU) [email protected]

2. CONTENTS DRUG DELIVERY SYSTEM CONVENTIONAL DRUG DELIVERY SYSTEM NOVEL DRUG DELIVERY SYSTEM

3. DRUG DELIVERY SYSTEM Drug delivery is the method of administering pharmaceutical compound to achieve a therapeutic effect in humans or animals. Most common methods of drug delivery includes the oral (through the mouth), topical (skin), trans-mucosal (nasal, buccal, sublingual, vaginal, ocular,rectal),parenteral(injection into systemic circulation) and inhalation routes. The drug delivery system can further be divided into two main types: Conventional drug delivery system. Novel drug delivery system.

4. CONVENTIONAL DRUG DELIVERY SYSTEM Conventional Drug Delivery System is the Classical methods for the delivery of Drug into the body. The Examples of these systems includes: Oral Delivery Buccal / Sublingual Delivery Rectal Delivery Intravenous Delivery Sub Cutaneous Delivery Intramuscular Delivery

5. Oral Delivery It includes tablets, capsules, syrups etc. taken directly through mouth and travels through GIT. Advantages of Oral Delivery: Convenience in Administration Non invasive Accurate and measured dose. Unit Dosage form Higher compliance Cheap to the patient. Disadvantages of Oral Delivery: Unconscious patients cannot take dose Low permeability. Degradation by Gastro-Intestinal enzymes. First pass metabolism Irregular absorption

6. Buccal / Sublingual Delivery Here tablets or chewing gums are placed under tongue (sublingual) and between cheeks (buccal). Advantages By-pass First pass metabolism Rapid absorption Low enzymatic activity Disadvantages Discomfort during dissolution Probability of swallowing- lost of effect Small doses

7. Rectal Delivery Here suppositories are placed inside rectum and it melts at body temperature to give quick effect. Advantages By-pass first pass metabolism Useful for children Disadvantages Absorption depends on disease state Degradation by bacterial flora Uncomfortable

8. Intravenous Delivery Drug in liquid form is administered directly into blood by injecting in vein with the help of sterile injector. Advantages Drug 100% bioavailable Rapid response Can administer drugs degradable in stomach. By-passes First Pass Metabolism Disadvantages Invasive Trained personnel Possible toxicity due to incorrect dosing Sterility

9. Subcutaneous Delivery Here liquid drug is administered in subcutaneous tissue by injecting with injector. Advantages Patient self-administration Slow , complete absorption By-pass FPM when placed at lower part of rectum. Disadvantages Invasive Irritation Inflammation Maximum dose volume - 2mL

10. Intramuscular Delivery The liquid drug is administered in the muscle tissue by injecting with injector. Advantages Drug is absorbed slowly, so prolong effect. Larger volume than subcutaneous By-pass first pass metabolism Disadvantages Invasive – patient discomfort Irritation , Inflammation May require some training

11. NOVEL DRUG DELIVERY SYSTEM (NDDS) It is a combination of advance technique and new dosage forms which are far better than conventional dosage forms and involves medicinal devices. It improves drug potency, control drug release to give a sustained therapeutic effect, provide greater safety and target a drug specifically to a desired tissue . Advantage of NDDS over conventional The conventional dosage forms provide drug release immediately and it causes fluctuation of drug level in blood depending upon dosage form. Therefore to maintain the drug concentration within therapeutically effective range need novel drug delivery system.

12. It provide optimum dose at the right time and right location. Efficient use of expensive drugs, excipients and reduction in production cost. Beneficial to patients, better therapy, improved comfort and standard of living . MODES OF NDDS Targeted Drug Delivery System Controlled Drug Delivery System Modulated Drug Delivery System Targeted Drug Delivery System The drug is delivered in such a way that drug is only active in the target area of the body (cancerous tissues) in which drug is released over a period of time in a controlled manner. e.g., Colon targeted drugs.

13. Controlled Drug Delivery System Release of drug is for long periods. In this the rate or speed at which the drug is released is controlled by modification in formulation. e.g. Nifidipine. Modulated Drug Delivery System Here the rate of drug release is controlled and modulated by devices such as nebulizer, MDI (metered dose inhaler) etc. Classification of NDDS with reference to release control 1. Matrix Diffusion Types: Here rate of release is controlled by diffusion of dissolved drug in the matrix. Rigid Matrix Diffusion : Here insoluble plastic materials like PVP & fatty acids are used.

14. Swellable Matrix Diffusion : Here gums are used. These are also called Glassy Hydrogels and popular for sustaining the release of highly water soluble drugs . Reservoir System: Here polymer content in coating, thickness of coating & hardness of micro-capsules control the release of the drug . Dissolution Matrix Type Here drug is homogeneously dispersed in rate controlling waxy medium like bees wax, castor oil etc . Encapsulation: Dissolution is controlled by coating system like use of cellulose, Polyethylene Glycols, polymethylacrylates, and waxes. Dissolution rate also depend upon coating material stability and thickness of coating film.

15. 3. Dissolution & Diffusion Controlled Release System: Drug is encapsulated in partially soluble membrane, pores are created due to soluble parts of coating film which permits entry of aqueous medium into core and drug dissolution starts by diffusion of dissolved drug out of system . Mixture of water soluble PVP and water insoluble ethyl cellulose is used for this purpose. 4. Water penetration/Osmotic Pressure Controlled NDDS : Drug may be osmotically active or drug may be combined with osmotically active salts like NaCl. 5. Chemically controlled NDDS: These systems change their chemical nature/structure when exposed to biological fluids. 6 . Hydrogels: Three dimensional network structures of hydrophilic polymers with chemical and physical cross links to provide desirable protection of drugs, proteins and peptides..

16. 7. Ion Exchange Resins Controlled Release Systems : Here ionisable drug is absorbed on ion-exchange resins granules then granules are coated with water permeable polymers using spray dryer technique. List of drug carrier in NDDS Nanosomes Liposomes Niosomes Nanoparticle Nanosphere Microsphere Microparticle Microemulsion Nanosuspension Micelles

17. Advantages of NDDS Decreased dosing frequency. Reduced rate of rise of drug concentration in blood. Sustained and consistent blood level within the therapeutic window. Enhanced bioavailability. To achieve a targeted drug release. Reduced side effects. Improved patient compliance.

18. REFERENCES: Teachers Handbook HSS 302 - NQ2014 Drug D elivery System PSS Central Institute of Vocational Education , Shyamla Hills, Bhopal