Chapter 19 of the Microcapsule.
Mikrokapsulating. Application of microcapsules. Technology
mikrokapsulating.
Microcapsules.
Mikrokapsulirovanie - process of the conclusion in the shell
Microscopic particles firm, liquid or gaseous
Medicinal substances. Apply microcapsules more often
In the size from 100 up to 500 microns. Particles in the size < 1 micron name
nanokapsulami.
Particles with liquid and gaseous substance have spherical
The form, with firm chastichkami - irregular-shaped.
Opportunities mikrokapsulirovanija:
à) protection of unstable medical products from
Influences of an environment (vitamins, antibiotics, enzymes,
Vaccines, wheys, etc.);
á) masking of taste of bitter and sickening medicines;
â) liberation of medicinal substances in the necessary site
A gastroenteric path (intestinal - soluble microcapsules);
ã) prolongation action. A mix of the microcapsule, distinguished
In the size, thickness and the nature of the shell, placed in one
A capsule, maintenance of the certain level of a medicine provides
In an organism and effective therapeutic action during
Long time;
ä) overlapping in one receptacle incompatible among themselves in
A pure kind of medicines (use of dividing coverings);
å) "transformation" of liquids and gases into a pseudo-firm status,
I.e. in the loose weight consisting of microcapsules with firm
The shell, filled liquid or gaseous medicinal
Substances.
Application of microcapsules.
As microcapsules issue a number of medicinal substances:
Vitamins, antibiotics, anti-inflammatory, diuretic,
Cardiovascular, antiasthmatic, protivokashlevye,
Soporifics, antitubercular, etc.
Mikrokapsulirovanie opens interesting opportunities at
Use of some medicinal substances which it is impossible
To realize in usual medicinal forms. An example - application
Nitroglycerine in microcapsules. Usual nitroglycerine in
Hypoglossal tablets or in drops (on a slice of sugar) possesses
The short-term period of action. Mikrokapsulirovannyj
Nitroglycerine possesses ability is long to be liberated in
An organism.
Technology mikrokapsulirovanija
Existing methods mikrokapsulirovanija:
Physical;
Physical and chemical;
Chemical.
Physical methods.
Physical methods mikrokapsulirovanija are numerous. To them
Methods drazhirovanija, dispersions, napylenija concern in
The pseudo-liquefied layer, dispergirovanija not mixing up liquids,
ekstruzionnye methods, an electrostatic method, etc. Essence of all
These methods consists in mechanical drawing the shell on
Firm or liquid particles of medicinal substances. Use
This or that method is in dependence from that, is
Whether "nucleus" (contents of a microcapsule) are firm or liquid substance.
A method drazhirovanija. We apply for mikrokapsulirovanija firm
Medicinal substances. The last as homogeneous
Crystal weight in the rotating drageeing boiler
Are sprayed from an atomizer by a solution plenkoobrazovatelja.
Formed a film dry up the heated up air, submitted in
The boiler. The received product is called as microdrops.
A method of dispersion. For mikrokapsulirovanija firm substances,
Which before it should be translated in a status thin
Suspensions. The size of received microcapsules 30 - 50 microns.
A method dispergirovanija in not mixing up liquids. For
mikrokapsulirovanija liquid substances. The size received
Microcapsules 100 - 150 microns. Here can be used drop
A method. Heated up emulsiju an oil solution medicinal
The substances, stabilized by gelatin (emulsija such as M/V),
dispergirujut in the cooled liquid paraffin with the help of a mixer. In
Result of cooling the smallest droplets become covered quickly
zastudnevajushchej the gelatinous shell. The stiffened balls separate
From liquid paraffin, wash out organic solvent and
Dry.
A method "napylenija" in the pseudo-liquefied layer. In devices such as the Joint venture - 30
And ÑÃ-30. The method is applicable for firm medicinal substances.
Firm a nucleus szhizhajut a stream of air and "napyljajut" on them a solution
Film-forming substance with the help of an atomizer. Hardening
Liquid shells occurs as a result of evaporation of solvent.
A method with the help tsentrifugirovanija. Under influence centrifugal
Forces of a particle of medicinal substances (firm or liquid) passing
Through a film of a solution plenkoobrazovatelja, become covered by her,
Forming a microcapsule.
In quality plenkoobrazovatelej solutions of substances are applied with
A significant superficial tension (gelatin, sodium alginat,
Polyvinyl spirit, etc.)
The electrostatic method - is developed in the USA. The size of microcapsules
From 50 up to 20 microns.
Physical and chemical methods.
Are based on division of phases, allow to conclude in the shell
Substance in any modular status and to receive microcapsules
Different on the size and properties plenok. In physical and chemical
Methods the phenomenon koatservatsii is used.
Koatservatsija - education in a solution high-molecular
Connections of the drops enriched with dissolved substance.
In result koatservatsii the biphase system for the bill is formed
Stratifyings. One phase represents a solution
High-molecular connection in solvent, another - a solution
Solvent in high-molecular substance.
A solution, richer high-molecular substance, often
It is allocated as droplets koatservata - koatservatnyh drops, that
It is connected to transition from full mixture to limited
Solubilities. Decrease in solubility is promoted by change
Such parameters of system, as temperature, rN, concentration and
Other
Koatservatsija at interaction of a solution of polymer and
Low-molecular substance is called stand. In its basis lays
The physical and chemical mechanism slipanija, « sgrebanija in a heap »
The dissolved molecules and branch from them water with the help
vodootnimajushchih means. Koatservatsija at interaction of two
Polymers education complex is called complex, and
koatservatov it is accompanied by interaction between (+) and (-)
Charges of molecules.
The way koatservatsii consists in the following.
All over again in the dispersive environment (a solution of polymer) in the way
dispergirovanija receive nucleus of the future microcapsules. Continuous
A phase thus is, as a rule, the water solution of polymer
(gelatin, karboksimetiltselljulozy, polyvinyl spirit and
Etc.), but can sometimes be and not water solution. At creation
Conditions at which solubility of polymer decreases,
There is an allocation from a solution koatservatnyh drops of it
Polymer which are besieged around of nucleus, forming initial
A liquid layer, so-called embrionalnuju the shell. Further
There is the gradual hardening the shell achievable with
The help of various physical and chemical receptions.
Firm shells allow to separate microcapsules from
The dispersive environment also prevent penetration of substance of a nucleus
Outside (see the circuit of education of microcapsules).
The circuit mikrokapsulirovanija with the help complex koatservatsii:
Chemical methods.
These methods are based on reactions of polymerization and polycondensation
On border of the unit of two not mixing up liquids (water-
Oil). For reception of microcapsules by this method in oil
Dissolve all over again medicinal substance, and then monomeasures
(for example, metilmetakrilat) and the corresponding catalyst
Reactions of polymerization (for example, peroxide benzoila). Received
A solution heat up 15 - 20 mines at t=55? C also pour in in water
A solution emulgatora. It is formed emulsija such as M/V, which
Maintain for end of polymerization within 4 hours.
Received polimetilmetakrilat, insoluble in oil, forms
Around of droplets of the last the shell. The formed microcapsules
Separate filtering or tsentrifugirovaniem, wash out and
Dry.
