DOSAGE FORMS

From Big Medical Encyclopedia

DOSAGE FORMS - the convenient for use and storage of a condition of pharmaceuticals or medicinal raw materials, characterized certain properties (structure, a dosage, a physical and chemical structure, a geometrical form) and providing optimal medical effect.

Fig. 1. Packagings with tablets and a dragee: 1 — a dragee; 2 — tablets; 3 — tablets, coated.
Fig. 2. Gelatin capsules: 1 — a cover; 2 — a bottom, on the right — the closed capsules of the different sizes (No. 7 — No. 1) full-scale.
Fig. 3. Capsules starched (wafers): 1 — covers; 2 — bottoms; 3 — the closed capsules of the different sizes full-scale.

Modern pharm, practice is characterized by variety of L. t., what allows clinical physicians to choose the most rational of them according to a condition of the patient and other factors.

There are classifications of L. t., based on the different principles: on aggregate state, a way of introduction and dispersion.

1. Classification by aggregate state, the oldest and widespread, divides L. t. on 4 groups: firm, soft, liquid and gaseous.

Tablets, a dragee, granules, powders, collecting, capsules, pencils medicinal belong to firm dosage forms. Tabulettae — dosed by L. t., received by pressing (or formation) pharmaceuticals or their mix and aids (fig. 1, 2, 3): multilayer tablets — with layer-by-layer inclusion of various pharmaceuticals; trituratsionny tablets — small doses of pharmaceuticals and the diluting substances about 0,05 g, received by formation are powerful; tablets, coated; implantation tablets — are intended for introduction to an organism with disturbance of an integrity of an integument. Dragee — dosed by L. t. rounded shape, received by a repeated lamination (pelleting) of pharmaceuticals and aids on granules (fig. 1,7). Granulae — homogeneous particles (grains, kernels) of pharmaceuticals of rounded, cylindrical or irregular shape of 0,2 in size — 0,3 mm. Pulveres — L. t., having flowability. Distinguish powders simple (one-component), difficult (from two and more components), divided into separate doses and undivided. Species — mix of several types which are cut up or istolchenny in large powder or whole medicinal raw materials, sometimes with addition of other pharmaceuticals (see. Collecting ). Capsulae — dosed powdery, granulated, is more rare the liquid pharmaceuticals concluded in a cover from gelatin — gelatin capsules (Capsulae gelatinosae; fig. 2), starch — the capsule starched, wafers (Capsulae amylaceae, s. Oblatae; fig. 3) or other biopolymer. Spansulae — the capsule, in a cut contents is a certain quantity of granules or microcapsules. Pencils are medicinal, or medical (Stili medicinales) — cylindrical sticks 4 — 8 mm thick and up to 10 cm long with the pointed or rounded off end.

Films medicinal — L belong to firm dosage forms. t. in the form of a polymer film, a film the eye, replacing eye drops (see. Medicinal films ).

Ointments, plasters, suppositories belong to soft dosage forms. Unguenta — L. t. a soft consistence for external use; ointments with the content of powdery substances of St. 25% are called pastes (Pastae).

Fig. 4. Rectal suppositories of various form: 1 — cylindrical; 2 — cone-shaped; 3 — sigarovidny.
Fig. 5. Diagrammatic representation of vaginal suppositories of various form: 1 — balls; 2 — ovul; 3 — pessaries (and — an anterior aspect, 6 — a ventral view).

Emplastra — L. t. for external use in the form of the plastic weight having ability after a softening at body temperature to stick to skin (see. Plasters ). Also plasters of the same weight applied on the flat carrier are applied. Suppositoria — firm at the room temperature and the dosed L melting (dissolved) at body temperature. t., intended for introduction to perigastriums. Rectal — candles distinguish suppositories (Suppositoria rectalia; fig. 4) and vaginal (Suppositoria vaginalia) which quite often have spherical shape — balls (Globuli; fig. 5), ovoid — ovul (Ovula), yazykovidny a flat body with the rounded-off end — pessaries (Pessaria), and also sticks (Bacilli). Pilulae — dosed by L. t. in the form of the balls weighing from 0,1 to 0,5 g prepared from the homogeneous plastic mass containing medicines and aids. Pills weighing more than 0,5 g are called a bolus (Boli). Some authors carry suppositories and pills to firm L. t.

Solutions, suspensions, emulsions, infusions, broths belong to liquid dosage forms. Solutiones — L. t., received by dissolution of one or several pharmaceuticals; cover true, colloid solutions and solutions of high-molecular compounds. Suspensions, or suspensions (Suspensiones) — liquid two-phase, coarse-dispersion systems in which solid matter is weighed in liquid and particle size from 0,1 to 10 microns fluctuate. Emulsa — L. t., being the two-phase system formed by liquids, insoluble in each other. Infusions and broth y (Infusa et Decocta) — aqueous extracts from medicinal vegetable raw materials or water solutions of extracts; differ from each other in the mode of extraction. The name of slime (Mucilagines) was assigned to group of the water extraction with high viscosity and also prepared using starch. Linimenta — dense liquids or gelatinous masses. Plasters liquid during the drawing on skin leave an elastic film. In the terminological dictionary approved as the uniform document by members of SEV at a meeting of experts on May 28 — 29, 1979, to L. t. are carried: syrups medicinal (Syrupi) — solution of medicinal substance in strong solution of sugar; tinctures (Tincturae) — the spirit, spirto-water or spirto-radio transparent extraction from medicinal vegetable raw materials received without heating and removal of extragent; extracts (Extracta) — the concentrated extraction from medicinal vegetable raw materials. Distinguish liquid extracts (fluida), dense (spissa), dry (sicca) and others, being galenovy drugs (see). Reference of syrups, tinctures and extracts to L. t. by a number of scientists-technologists it is not divided.

Gaseous dosage forms are applied is inhalation (Formae medicamentorum pro inhalationibus), in the form of gases, vapors and aerosols. An aerosol — L.f. in an extra packing (see. Aerosol devices ), representing a disperse system, in a cut a dispersion medium is gas or gas mixture, and the dispersed phase consists of firm or liquid particles of pharmaceuticals (medicinal aerosols).

This classification did not lose the value. It is convenient for primary division and systematization of L. t., it is used during the training of doctors and druggists and at statistical studying and the analysis of a compounding.

Aggregate state determines to a certain extent the speed of action of L. t. (liquid L. t. work quicker, than firm, and gaseous quicker, than liquid); also the possibility of giving to medicine of this or that form is connected with aggregate state. However aggregate state speaks a little about technological processes which were applied at preparation of this or that of L. t.

2. Classification by a way of introduction divides all L. t. on two groups: enteral, entered through went. - kish. a path, and parenteral, entered passing went. - kish. path.

The drugs entered belong to enteral dosage forms: a) orally (per os), include the most extensive group L. t. — tablets, dragee, powders, solutions, suspensions, emulsions, infusions, broths, slime, pill; b) it is sublingual (sub linguam) — tablets; c) rektalno (per rectum) — candles.

The forms applied by an injection belong to parenteral dosage forms (see. Injection ); on skin — ointments, pastes, linimentums, powders (powders); on mucous membranes — ointments, powders, solutions, drops, balls, ovul, pessaries — vaginalno (per vaginam), sticks — uretralno (per urethram); by inhalation, it is inhalation — gases, aerosols. Liquid sterile L are applied to injections (Formae medicamentorum pro injectionibus). t. (solutions and suspensions), the integrities of integuments entered into an organism with disturbance.

Depending on a route of administration or a method of dosing of L. t. have special names. E.g., to liquid L. t. drops (Guttae) intended for use in the form of drops inside, eye, ear, in a nose belong (see. Drops ), and mixtures (Mixturae) — liquid L. t. for internal use, dosed by dining rooms, dessert and teaspoons. Some liquid L. t. call rinsings, lotions, poultices, washings, powders — powders, powders. This classification is convenient for the doctor since the doctor makes the decision on the choice of a way of introduction of medicine taking into account a condition of the patient and other circumstances. This classification has and tekhnol, value as the route of administration defines, e.g., a degree of dispersion of pharmaceuticals, the mode of preparation (aseptic preparation and sterilization of L. t. for injections and eye drops).

3. Dispersologichesky classification it is widespread in pharmacy. According to this classification all L.f. consider as disperse physical. - the chemical systems having a certain internal structure and demanding for the preparation the corresponding operating sequence in the general scheme tekhnol, process. Modern dispersologichesky classification distinguishes two basic groups: svobodnodispersny and svyaznodispersny systems.

Unstructured systems in which particles of a dispersed phase are not connected with each other belong to svobodnodispersny systems, freely move in a dispersion medium under the influence of heat or gravity. Depending on properties of a dispersion medium distinguish the following svobodnodispersny systems: with a fluid dispersion medium (solutions, suspensions, emulsions, infusions, broths, slime, liquid L.f. for injections); with a gaseous dispersion medium (gas mixtures, aerosols, powders, collecting). The essence tekhnol, processes in these cases comes down to crushing, dissolution, peptization, suspending, emulsification.

Svyaznodispersny systems — systems in which particles of a dispersed phase are connected with each other and with a dispersion medium at the expense of molecular, adsorptive and other forces and form peculiar grids, or frameworks. Depending on properties of a dispersion medium and its communication with a phase L. t. this system it is possible to divide into the following groups: with viscously y or it is firm y Wednesday (ointments, pastes, plasters, suppositories, sticks, pills); with a solid dispersion medium (tablets, granules, pencils). Essence tekhnol, processes at production of L. t. this group comes down to dispersion of a phase, its hypodispersion in a dispersion medium and to creation of the structured system.

K L. t. a number of requirements is imposed: compliance physical. - chemical properties of the substances making them, firmness at storage, the speed and completeness to lay down. effect (the bystry or prolonged action — see. Drugs of the prolonged action ), possibility of masking of off-flavor, accuracy of dosing of pharmaceuticals, convenience of reception, simplicity and speed of production, etc. What big advantages the L possesses. t., the longer it remains in practice. Some L. t., widely applied in the past, did not pass test time; e.g.: yulepa (Julepia) — mix of medicinal substances in solution of sugar in fragrant waters; lamellas (Lamellae) — thin jellylike plates from gelatin, glycerin and medicinal substances; squashes (Electuaria) — mix of powders and extracts with honey or syrups; tserata, or descents — dense ointments, a prototype of modern pastes; suckers — complex mixtures from uparenny extracts of plant materials with honey and other means.

To number of rather recently applied L. t. pastils, or the flat cakes reminding the tablets which are rolled out from pasty mixes of pharmaceuticals with sugar or chocolate weight and dried up, and also elixirs, essences, uksusomeda, smelling salts, etc. belong.

In 60 — the 70th 20 century were widely adopted new L. t. — very perspective medicinal films. Are stable and convenient during the transportation the flavored dry suspensions and dry emulsions — dry blends of powders of the medicinal, corrective and emulsifying or suspending substances (suspending or emulsification make them just before reception). In such look release many antibiotics, hormones, vitamins. Much attention is paid to creation of L. t. with the set properties, i.e. with a certain therapeutic orientation. To such L. t. spansules which granules and microcapsules are covered with various covers capable to be dissolved (to break up) in a certain environment and through certain time belong. Many classical L. t. are intensively forced out by high-speed inhalation L. t., first of all aerosols. Considerable efforts of scientific and production institutions are directed to creation of children's L. t., the by-effects convenient providing optimum therapeutic effect with a minimum in use, in the minimum degree injuring mentality of the child, having palatability, a smell and attractive outward.

The pharmaceutical researches conducted in 60 — the 70th, (see. Biopharmacy ) showed that effect of medicines substantially depends on a type of L. t. So, the sulfate of atropine entered inside in the form of pills is soaked up in 30 — 40 min., entered in the form of powder — in 20 — 30 min., and at an injection — in 1 — 3 min. The maximum concentration of pyramidon in an organism from suppositories and solution is created in 1 hour, from powder — in 2 hours, from solution with corrective structure and tablets — in 4 hours.

Correctly picked up by L. t. thus, provides completeness of effect of medicine, and unsuccessful can reduce it, and even sometimes do harm to the patient. At the same time methods of preparation of L are of great importance. t., choice of bases, aids and other additives. In same L. t. it is possible to receive effect of medicine of different force, and sometimes and various character. E.g., introduction to L. t. insignificant amounts of surfactants promotes sharp increase in absorbability and consequently, and forces of effect of medicines; converse effect — receiving an inactive form — replacement of lard with vaseline in ointment with potassium iodide gives, action to-rogo can be shown only after absorption of ointment.

At the choice of L. t. it is also necessary to be guided physical. - chemical properties of medicine, degree of its stability, a state and age of the patient, a possibility of use of medicine depending on the conditions surrounding the patient and so forth. Solutions, e.g., are well dosed and are convenient for reception, but many pharmaceuticals in the dissolved look are nonstorable (infusions, broths, slime, an emulsion) and therefore the quantities prescribed the patient shall not exceed three-day requirement (on condition of storage in the cool place — better in the refrigerator). Powders, tablets are dosed more precisely, than solutions, but it is not recommended to appoint them the patient with inflammatory or ulcer processes went. - kish. a path, with disturbance of the act of swallowing, the patient in unconsciousness, to small children. Liquid and soft L are preferable to children. t. Suffering hron, diseases it is reasonable to appoint drugs in the form of tablets, a dragee, pills which can be had at themselves and to accept in any conditions. At prescription of drugs inside it is necessary to care for improvement of their taste. To patients who cannot accept peroral L. t., the rectal way of introduction of drugs excluding such by-effects as nausea, vomiting, etc. is recommended. Injection L. t. provide speed of action, accuracy of a dosage, a possibility of introduction to the patient in unconsciousness.

Until recently majority of L. t. produced in drugstores. Now factory production of so-called ready L prevails. t. on the approved standard copy-books. Implementation in medical practice of ready L. t. increased quality of drugs, unloaded drugstores from unproductive work and accelerated receiving drugs by patients. Now in drugstores prepare only drugs on individual copy-books, and also unstable L. t., napr, infusions, broths, slime, emulsion, etc.

In veterinary science apply generally the same L. t., and the same requirements regarding manufacturing techniques, issues and storages are imposed to them. There is a difference in dosages of active ingredients, total amount (quantity) of the prescribed and released medicine and in ways of their use. Are most convenient in vt. to practice gelatin capsules and preferential elastic; a bolus weighing from 0,5 to 50 g for which production as form-building substances, except usually used for pills, use rye flour, a crumb of rye bread more often; squashes — soft L. t. for internal use, before extended and in medical practice. As form-building substances at production of squashes serve powders of a licorice and marshmallow root, linen and rye flour, sugar syrup, honey, treacle, carrot juice, vegetable oils, etc.


Bibliography: I. A. Tekhnologiya's ants of drugs, M., 1971; Tentsova A. I. both And yes x and I. S N. Dosage form and therapeutic effectiveness of drugs, M., 1974, bibliogr.

A. Y. Tentsova.

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