Chapter 10 Tablets. The basic
Requirements to tablets and theoretical bases tableting.
Accuracy of batching. Granulating. Mechanical durability.
Dispersing.
Tablets.
Definition. Tablets - firm dosed out LF, received
Pressing medicinal substances, mixes medicinal and
Auxiliary substances or formation of special weights and
Intended for internal, external, sublingvalnogo or
parenteralnogo applications. At intake of a tablet wash down
Water, sometimes them preliminary dissolve in water.
On a way of reception of a tablet subdivide into 2 types:
Pressed (a method of pressing - the overwhelming majority) and
trituratsionnye (a method of formation - 1-2 %, nitroglycerine).
The first data on tablets:
1844ã. - in England the patent for reception of tablets kalija is declared
A hydrocarbonate a method of pressing.
1846ã. - manufacture of tablets in the USA, France is imposed,
Switzerland, Germany.
1895ã. - openly the first tabletochnoe manufacture in Russia on
A factory of military-medical preparations in Petersburg (nowadays LPO
"Progress").
1900ã. - the first scientific research devoted to tablets-
The dissertation of professor L.F.Iljina.
1901ã. - the tablet as dosed out LF is switched on in Swedish
The pharmacopoeia VII.
From now on she is officially recognized worldwide.
Now tablets make about 80 % of total amount LF.
The characteristic. The round form with flat or biconvex
A face surface. The size from 3 up to 25ìì in diameter. Tablets
In diameter > 25 mm are called as briquettes. Tablets dimetrom > 9ìì
Have one or 2 + risks for division into 2 or 4 parts, that
To vary a dosage of medicinal substance. Weight of tablets from
0,05 up to 0,6ã it is defined by a dosage of medicinal substance.
Purpose:
peroralno, it is soaked up by a mucous membrane of a stomach or
Intestines;
sublingvalno - it is soaked up by a mucous membrane of an oral cavity;
asepticheski prepared and used for reception
inektsionnyh solutions or used for implantation;
Used for preparation of solutions for rinsings,
Syringings, etc.;
Pressed urethral, vaginalnye and rektalnye LF.
As well as others LF, tablets have the (+) and (-) the parties. To them
(+) to qualities to tablets concern:
à) full mechanization of process of the manufacturing, providing
High efficiency, cleanliness and gigienichnost tablets;
á) accuracy of batching of medicinal substances;
â) the portability of tablets allowing quickly to release
Necessary big LP and facilitating job of drugstores on
To transportation and storage;
ã) long safety of medicinal substances in pressed
A status;
ä) masking unpleasant organolepticheskih properties (taste,
A smell). It is reached by imposing of shells from sugar; cocoa;
Chocolate;
å) an opportunity of a combination of the medicinal substances incompatible on
To their physical and chemical properties in other forms;
æ) localization of action LP. This property is reached by
Drawings shells of special structure, soluble in sour
(Stomach) or in alkaline (intestines) to environment;
ç) prolongation action of medicinal substances;
è) regulation consecutive vsasyvanija several
Medicinal substances from a tablet in the certain intervals
Time - creation of multilayered tablets;
ê) the prevention of mistakes at holiday and reception of medicines,
Achievable vypressovyvaniem on a tablet of inscriptions.
Alongside with it tablets are not free and from the some people (quite
Eliminated) lacks:
à) at storage of a tablet can lose the raspadaemost and
To be cemented or, on the contrary, to collapse;
á) with tablets in an organism the substances which are not having are entered
The therapeutic values sometimes causing some collateral
The phenomena (for example, talc irritates mucous);
â) separate LP (NaBr and KBr) form in a zone of dissolution
vysokokontsentrirovannye solutions which can cause strong
Irritation of mucous membranes. This lack is eliminated, such
Tablets before reception crush and dissolve in certain
Quantity of water;
ã) not all patients, it is especial children, can freely swallow
Tablets.
The basic requirements to tablets and theoretical bases
tabletirovanija.
To tablets 3 basic requirements are showed:
Accuracy of batching - uniformity (uniformity)
Distributions of working substance in a tablet; and also
Correctness of weight of a tablet;
Mechanical durability. Hardness, fragility, fragility
Characterize quality of tablets. Tablets should possess
Sufficient durability to remain intact at
Mechanical influences during packing, transportation and
Storages.
Raspadaemost - ability to break up or be dissolved in
The terms regulated by the reference document.
Accuracy of batching. Depends on many conditions. First, from
Uniformity tabletiruemoj weights which is provided at
Careful hashing medicinal and auxiliary substances
And uniform their distribution in a lump. If the weight will consist
From particles of the different size (different weight), at stirring
Loading voronki the mix is stratified: large particles
Remain from above, fine fall downwards. Stratifying causes
Change of weight of tablets. Speaking about uniformity of a material,
Mean also his uniformity under the form chastichek. Obviously,
That chastichki, having a different spatial outline at
To the same weight, will be placed in a matrix jack with
Different compactness, that also will be reflected in weight of tablets.
Second! Accuracy of batching depends on speed and
Non-failure operation filling of a matrix jack. If for short
Time of stay voronki above a matrix aperture gets enough sleep
It is less than material, than can accept a matrix jack, tablets
Always will be smaller weight. How it is possible to avoid all
These troubles?! Distinction of the form, accordingly, weights
Particles, from here their stratifying and receipt in a matrix
A tablet of the machine with different speed? Resorting to
A granulating!
Granulirovanie - process of transformation poroshkoobraznogo a material
In particles (grain) of the certain size. It is impossible to achieve
Absolute uniformity of granules, however, varying a parity
Fractions granuljata, it is possible to establish optimum structure.
Granulirovanie improves flowability, provides uniform
Speed of receipt in a matrix jack strictly certain
Quantities tabletiruemoj weights
Mechanical durability. Her causes vzaimostsepljaemost
Particles. What forces provide coupling particles at
tabletirovanii? What mechanism of transformation of a loose material,
Consisting of the separate particles not connected among themselves, in
A firm body - a tablet? In the beginning of process pressing
tabletiruemaja the weight is condensed, there is closer
Rapproachement of particles conditions for display of forces also are created
Intermolecular and electrostatic interaction. Forces
Intermolecular interaction are shown at rapproachement of particles
On distance 10-6 - 10-7 see. At the first stage of pressing
A material there is a rapproachement and condensation of particles a material for
The bill of displacement of particles be relative each other filling of emptiness.
At the second stage to increase in pressure of pressing occurs
Intensive condensation of a material at the expense of filling emptiness and
Various kinds of deformations which promote more
To compact packing particles. Deformation which occurs for
The bill of elasticity of a material, helps particles mutually
To put, that increases a contact surface. Same
The deformation occuring at the expense of plastic promotes also
Properties of a material which forces particles to change the
The form and more densely to adjoin to each other. At the second stage
Pressing and a loose material it is formed compact porous
A body possessing sufficient mechanical durability.
And, at last, at the third stage of pressing occurs volumetric
Compression of the formed compact body.
Mechanical durability depends on the applied pressure, however,
Rather essentially as pressure will develop at
Pressing. Pressure is called rigid if it will arise
Suddenly - in shock tablets machines. A surface of a tablet
Under impact of punches it is strongly warmed up (transition mechanical
Energy in thermal) owing to what substances are alloyed and
Form a continuous cementing layer.
Pressure is called progressive if it accrues gradually
- in rotational tablets machines. Progressive pressure gives
The best results as provides pains long
Influence of pressure on tabletiruemuju weight. Than it dlitelnee,
The more full air will be removed from weight, which then, the ambassador
Removals of pressure, extending, cannot render destroying
Influence on tablets. Besides it is considerably weakened
Warming up of a tablet at a surface that excludes harmful
His influence on the substances included in a tablet.
However application of a high pressure at pressing can (-)
To influence quality of tablets and to promote deterioration of tablets
Machines. It is possible to compensate a high pressure addition
The substances possessing big dipolnym the moment and providing
stsepljaemost particles at rather small pressure. Water,
Possessing sufficient dipolnym the moment, being "bridge" between
Them.
To linkage of particles difficultly soluble and insoluble LP water
Will interfere. In such cases addition is required
Substances with higher force of coupling (solutions of starch,
Gelatin, etc.). And again resort to a granulating, that from it
The help in tabletiruemuju weight to enter connecting substances,
Which raise plasticity of medicinal substances, and
The property named adhesion which causes is shown
Sticking particles to each other.
Raspadaemost. Too high durability of a tablet influences
On her raspadaemost: time raspadaemosti grows, that
(-) affects quality of a tablet. At sufficient
It is necessary for mechanical durability to provide good
raspadaemost tablets. Raspadaemost depends on many
The reasons: 1) from quantity of connecting substances. Tablets
Should contain them so much, how much it is necessary for
Achievements of required durability; 2) from pressure
Pressing: excessive pressure worsens raspadaemost
Tablets; 3) from quality of loosening substances,
Promoting raspadaemosti tablets. On physical
To structure of a tablet represent a porous body; at
Their immersing in a liquid, last will penetrate into all
The capillaries penetrating thickness of a tablet. If in a tablet
There will be well soluble additives they will be
To promote fast raspadaemosti her.
