Ppt microencapsulation

DESCRIPTION ON MICROENCAPSULATION

1. MICROENCAPSULATION By SANA TABASSUM (B.Pharm) Under the guidance of Mrs.Ch.S VIJAYA VANI, M.Pharm . Associate Professor, Department of Pharmaceutics. A Presentation On CMR COLLEGE OF PHARMACY

2. DEFINITION Microencapsulation is the process by which tiny solid particles or droplets of liquid are surrounded or coated with a continuous film of polymeric material to produce capsules in the micrometer to millimeter range. The product obtained by this process is called as microcapsules. 1 Microcapsule

3. MICROCAPSULES Microcapsules in blood stream Microscopic view of microcapsules

4. Advantages of microencapsulation Masking of bitter taste drugs. Eg: Ofloxacin. Conversion of liquid to pseudo solid. Eg: Eprazinone. 2 Environmental protection. Eg: Vit.A.Palmitate. Reduction of hygroscopicity .Eg: NaCl. Reduction of vaporization of volatile drugs. Eg: Methyl salicylate. Prevention of incompatibilities among drugs. Eg: Aspirin and Chlorpheniramine maleate . 2

5. Disadvantages of Microencapsulation. Possible cross reaction between core and shell material. Difficult to achieve continuous and uniform film. Shelf life of hygroscopic drugs is reduced. More production costs. More skill and knowledge is required. 2

6. MECHANISMS OF DRUG RELEASE Degradation controlled monolithic system Diffusion controlled monolithic system Diffusion controlled reservoir system Erosion

7. MECHANISMS OF DRUG RELEASE Degradation controlled monolithic system -Drug releases on degradation of matrix. Diffusion controlled monolithic system -Drug released by diffusion then degradation of matrix occurs. Diffusion controlled reservoir system -Drug from capsule diffuses then rate controlling membrane erodes. Erosion -Due to pH and enzymatic hydrolysis. 2

8. CLASSIFICATION OF MICROCAPSULES 2 Mononuclear Polynuclear Matrix Mononuclear with multiple shells

9. MATERIALS INVOLVED IN FORMULATION A)Core Material: Specific material to be coated. It may be liquid or solid. Liquid core may be dissolved or dispersed material. 3

10. Core Material Purpose Final Product Form Acetaminophen Taste masking Tablet Potassium chloride Reduces gastric irritation Capsule Isosorbide dinitrate Sustained release Capsule Examples of core material

11. B)Coating Material: Inert substance which coats on core with desired thickness. Composition of coating solution Inert polymer. Plasticizer- Triethylcitrate, glycerin Solvents- Water,cyclohexane. Co solvents-Glycerol, sorbitol .

12. Examples of various coating material 3 Category of Coating Material Examples Water soluble resins Gelatin, Polyvinylpyrrolidone(PVP). Water insoluble resins Ethyl cellulose, Polyethylene. Waxes and lipids Paraffin, Carnauba, Beeswax. Enteric resins Shellac, Zein.

13. TECHNIQUES TO MANUFACTURE MICROCAPSULES S.No Physical Methods Chemical Methods A) Air Suspension Solvent Evaporation B) Pan Coating Polymerization C) Coarcervation Phase Separation Interfacial Polymerization In-situ Polymerization D) Multi-orifice Centrifugal Process E) Spray Drying & Spray Congealing F) Fluidized Bed Technology

14. A)Air Suspension(Wurster Method) Within the coating chamber, particles are suspended on an upward moving air stream. Spraying of coating material on the air suspended particles. The cyclic process is repeated depending upon purpose of microencapsulation. Air stream serves to dry the product. 3

15. Advantages: Disadvantages: Various coating material can be used. Applicable only to solid core material. Capacity is more Agglomeration of the particles WURSTER APPARATUS

16. B) Pan Coating The particles are tumbled in a pan while the coating material is applied slowly as solution or atomized spray to the core. To remove the coating solvent, warm air is passed over the coated materials or dusting of talc is done.

17. Medicaments are usually coated onto nonpareil sugar seeds and then coated with polymers. 3 Advantages: Disadvantages: Suitable to larger particles. Time consuming. Sustained release preparations. High material loss.

18. C) Coacervation Phase Separation: Simple coacervation Complex coacervation A desolvation agent is added for phase separation It involves complexation between two oppositely charged polymers. Steps involved in this process are:- Formation of three immiscible phases. Deposition of liquid coating material upon the core material. Rigidization of coating.

19. Coacervation process

20. Various methods to obtain three immiscible phases: Temperature change Incompatible Polymer Addition Non-Solvent Addition Salt Addition Polymer-Polymer Interaction(Complex Coacervation)

21. Temperature change: Temperature-composition phase diagram for a binary system of a polymer and a solvent. TEMPERATURE POLYMER CONCENTRATION % X A B C D E F G Point X represents –single phase. The phase-boundary curve indicates that with decreasing temperature. One phase becomes polymer rich. Other phase becomes polymer poor. Eg: N-acetyl p-amino phenol. 4

22. Non-Solvent Addition: A liquid that is a non-solvent for a given polymer can be added to a solution of the polymer to induce phase separation. Eg: Addition of isopropyl ether to CAB dissolved in methyl ethyl ketone. C ore: Methyl scopolamine HBr. 4 X A B C D E SOLVENT 100% 100% POLYMER 100% NON SOLVENT Phase diagram for phase-separation/ coacervation induced by Non Solvent Addition

23. Salt Addition Soluble inorganic salts can be added to aqueous solutions of water-soluble polymers . Eg: Sodium sulfate, Core-Vitamin in corn oil. 4

24. Polymer-Polymer Interaction (Complex Coacervation): Steps involved: 4 Formation of an O/W emulsion Formation of the coating Stabilization of the coating A C B WATER 100% 100% P - 100% P+ Ternary Phase diagram X

25. D) Multi-orifice Centrifugal Process Advantages: Encapsulates both solid and liquid materials. Production rate is more. It utilizes centrifugal forces to hurl a core material particle through an enveloping microencapsulation membrane . 4

26. E ) Spray Drying and Spray Congealing:

27. Spray Drying Spray Congealing Coating solidification effected by rapid evaporation of solvent in which coating material is dissolved . Coating solidification is effected by thermally congealing a molten coating material. 4 Advantages: Low bulk density product. Porous nature capsules. Free flowing particles.

28. F ) Solvent Evaporation Advantages: Encapsulation of hydrophobic and hydrophilic drug. Simple technique. Encapsulation of solid and liquid drug.

29. G ) Polymerization Interfacial Polymerization In-situ Polymerization

30. NOVEL METHODS A) Vibration Technology A fluid stream of liquid core and shell materials is pumped through concentric tubes and forms droplets under the influence of vibration. 1

31. B ) Jet Cutter Technology A solid jet of fluid coming out of a nozzle by means of rotating cutting wires is cut into cylindrical segments which then form beads due to surface tension on their way to a hardening device. 1

32. C ) Rapid Expansion Of Super Critical Solution(RSS) Core and the shell material are maintained at high pressure and then released at atmospheric pressure through a small nozzle. Sudden drop in pressure causes desolvation of the shell material. 1

33. APPLICATIONS To reduce gastric and other GIT irritations. Eg: Aspirin preparations. Prolonged release dosage forms preparation. Preparation of enteric-coated dosage forms . Replacement of therapeutic agents (not taken orally like insulin), gene therapy and in use of vaccines for treating AIDS, tumors, cancer and diabetes. Delivery of DNA vaccines. Prodrug approach. Eg: Minocycline HCl. Biodegradable and biocompatible microparicles preparations.Example: Risperidone or testosterone. 5

34. Marketed formulations prepared using microcapsules 5 S.No Brand Name Generic Name Category of drug 1. Lupin Cefadroxil Antibiotic 2. ZORprin CR Aspirin Anti-arthritic 3. Glipizide SR Glucotrol Anti diabetic

35. REFERENCES http://www.authorstream.com/Presentation/vivekchauhan-1147305-microencapsulation. Hammad umer et.al,” International Journal of Research in Pharmaceutical and Biomedical Sciences” ISSN: 2229-3701. S. S. Bansode et.al,” Institute of Pharmaceutical Education And Research”, Volume 1, Issue 2, March –April 2010; Article 008 . Lachman LA, Liberman HA, Kanig JL. The Theory and Practice of Industrial Pharmacy. Mumbai, India: Varghese Publishing House; 3:414-415. http://www.authorstream.com/Presentation/thokesagar-1295371-shree/

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