Micro Encapsulation - It is a process in which tiny particles or droplets are surrounded by a coating to give small capsules many useful properties.
Micro Capsule - It is a small sphere with a uniform wall around it.
Morphology of Microcapsules -
M ononuclear Poly
(core-shell) microcapsules contain the shell around the core.
nuclear capsules have many cores enclosed within the shell.
M atrix
encapsulation in which the core material is distribute homogeneously into the shell material.
Microencapsulation Techniques:-
1. Physical methods: Pan coating Air-suspension coating Centrifugal extrusion Vibration nozzle Spray drying 2. Chemical methods: Interfacial polymerization In-situ poymerization M atrix
poymerization
BENEFITS OF MICROENCAPSULATION 1. M icroorganism
and enzyme immobilization.
2. Protection against UV, heat, oxidation, acids, bases. 3. Enhance visual aspect and marketing concept.
4.Improved shelf life due to preventing degradative reactions (dehydration, oxidation). 5. M asking of taste or odours. 6. Handling liquids as solids. 7.There is a growing demand for nutritious foods for children which provides
them with much needed vitamins and minerals during the growing age. 8. Improved shelf life due to preventing degradative reactions.
9.Controlled and targetted release of active ingredients.
Preparation
& Evaluation of the M icroencapsules of Aspirin drug.
On
The first research leading to the development of microencapsulation procedures for pharmaceuticals was published by Bungenburg de Jong and Kass in 1931 and dealt with the preparation of gelatin spheres and the use of gelatin coacervation process for coating.
July
5, 1955, Dayton, Ohio, resident and National Cash Register Company employee Barrett K. Green received a patent for the process of microencapsulation.
Green
first applied his new invention to typing paper. He used microencapsulation to manufacture the first carbon-free carbon paper in the world.
The
first company to utilize scratch-and-sniff technology was the Dayton Power & Light Company.
DRUG CANDIDATE Chemical Name
:- ACETYLESALICYLIC ACID
IUPAC Name
:- 2-Acetyloxybenzoic acid
Molecular weight
:- 180.160
Formula
:- C9H8O4
Melting point
:- 138 -140°C (280± 284 °F)
Description
:- White crystel
Solubility
:- freely soluble in ethanol,soluble in chloroform
& in ether,Slightly soluble in water. A spirin
is acetylsalicylic acid. It is rapidly converted in the body to salicylic acid which is responsible for most of the actions. It is one of the oldest analgesicantiinflammtory drugs and is still widely used.
FORMULATION POCEDURE
Materials:-
Aspirin, Acetone, Cyclohexane, , Ethanol, Heavy liquid paraffin, ethyl cellulose, and water. All chemicals used in the experiments were of analytical grade. Method: M icrocapsules
of ethyl cellulose containing aspirin were prepared by an emulsion-solvent evaporation method as reported by Nokhodchi and Farid, 2002. Aspirin microcapsules were prepared by dissolving polymers in an organic solvent to form a homogeneous polymer solution. The core material, aspirin was added in a thin stream of heavy liquid paraffin. The mixture was agitated using a propeller mixer with the rotation speed 600rpm.The dispersed phase consisting of drug and polymer EC was immediately transformed into fine droplets, which subsequently solidified into rigid microcapsules due to solvent evaporation. The liquid paraffin was decanted, and the microcapsules were collected, washed twice in cyclohexane to remove any adhering oily phase (liquid paraffin), and was air dried for at least 12 h to obtain discrete microcapsules. The quantity of polymer, drug and the solvent used is given in Table.
TABLE FORMULATION
DRUG:POLYMER
LIQUID PARAFIN (ml)
ETHANOL (ml)
ETHYL CELLULOSE (gm)
Aspirin : Ethyl cellulose
4:1
60
10
1
1. Shape and size 2. Color 3. Thickness of capsule size 4. Disintegration test 5. Weight variation test 6. Dissolution 7. Microscopy studies
1.
The shape of capsule was found to be oval and size was 0 no. capsules.
2.
The colour of the capsule was found to be white and transparent.
3.
Thickness of the capsule shall was to be found 0.5mm.
4.
By performing disintegration test on micrencapsules, disintegration time was to be taken 1.5 minute.
5.
Weight of empty capsule shell was 48mg. Average weight of one capsule was 283mg & the individual capsules were fall with in 90-110 % of the average weight.
6.
Drug release was found to be maximum in 5hrs.
7.
Microscopy: Pure Aspirin crystal
Microencapsulated Aspirin Crystal
Encapsulation
is a useful method for prolonging the drug release from dosage forms and reducing adverse effects. Microcapsules are composed of a polymer wall enclosing a liquid core or other body of material. The emulsion solvent evaporation (ESE) method can be used to prepare microcapsules. Sustained
release formulation of Aspirin would reduce the undesired side effects, reduce frequency of administration and improves patient compliance. In this present study, Aspirin microcapsules were prepared by emulsion solvent evaporation technique using EC. Ethanol was used for the preparation of microcapsules.
1.
CLOPIGREL-A cap® [ USV]
2.
CLOPITAB-A cap® [ Lupin (Pinnacle)]
3.
ARRENO cap® [ Intas]
4.
ATCHOL ASP cap® [ Aristo]
5.
ATOPLUS cap® [ Triton (Calyx)]
6.
ATOSA cap® [ Skymax]
7.
AZTOR ASP 150 cap® [ Sun ]
8.
AZTOR ASP cap® [ Sun (Aztec)]
9.
CERUVIN-A tab® [ Ranbaxy]
10. CLASPRIN cap® [ Biocon] 11. CLOPISA cap® [ Skymax] 12. AZTOR ASP cap® [ Sun (Aztec)]
1.
Herber A. Leberman & Leon Lachman; Theory & practice of industrial pharmacy; Lea & febiger,Philadelphia,USA.
2.
Reynolds JE, ed. Analgesic anti-inflammatory and antipyretic. In: Martindale: The complete drug reference. 32nd ed. Parfitt K, Massachusetts. 1999: 2 ±12.
3.
Rowland M, Riegelman S. Pharmacokinetics of acetyl salicylic acid and salicylic acid after intravenous administration in man.J Pharm Sci. 1968; 57: 1316±1319.doi:10.1002/j ps.2600570807.
4.
Rowland M, Riegelman S.Pharmacokinetics of acetyl salicylic acid and salicylic acid after intravenous administration in man.J Pharm Sci. 1968; 57: 1316±1319.doi:10.1002/j ps.2600570807.
5.
Arshady, R.: Microspheres, microcapsules and liposomes. General concepts and criteria, Arshady, R., Eds., Citrus Books, London, United Kingdom, 1999, 11-45.
6.
Benoit, J. -P., Marchais, H., Rolland, H., and Velde, V. V.: Biodegradable microspheres: Advances in production technology, Benita, S., Eds., Marcel Dekker, Inc., New York, N.Y., 1996, 35-72.
7.
Bayer HealthCare AG. Aspirin: History & Structure. http://www.aspirin-foundation.com
