Definition and properties
Tablets are solid dosage forms containing one or more active pharmaceutical ingredients (exception: placebos). They are intended to be taken by mouth. Tablets may be swallowed unchewed or chewed, dissolved in water or allowed to disintegrate before use, or retained in the oral cavity, depending on the galenic form. The Latin term (French ) is derived from meaning to squeeze or press together. Tablet can be translated as tablet or small board. Tablets have different shapes. They can be round, oblong, oval, and even square. Their surfaces are flat or convex and the edges can be beveled and rounded. They may have breakage notches and breakage grooves, embossing, writing and other markings. Tablets today are often provided with a coating. They are referred to as film-coated tablets. They are white or colored with dyes, see dyes in medicines. The first tablet presses were invented in the 19th century. Tablets are the successors of pills, which have become meaningless and are no longer produced. Hormonal contraceptives (“the pill”) are also, in fact, tablets.
Production
Tablets are manufactured by compressing a constant volume of a powder or granules under a high pressure. Other suitable processes are available, such as an extrusion, casting, 3D printing, or freeze-drying. Tablets must have sufficient strength so that they do not crumble or break during handling. The drugs are usually produced by machine. However, there are also manual presses that can be used to produce them yourself. However, this should be left to professionals due to the risks involved (see under DIY medications). When a powder mixture is pressed with or without excipients, it is referred to as direct tabletting. In most cases, however, granule production is necessary before pressing.
Excipients
Almost all tablets contain excipients. These include, for example (selection):
| Filler | Mass and volume: lactose, starch, microcrystalline cellulose. |
| Binder | Cohesion and strength: microcrystalline cellulose, hydroxypropyl cellulose, starch, povidone. |
| Disintegrant (disintegrant). | Disintegrant in stomach and intestine: starch, alginates, celluloses. |
| Lubricants and lubricants | Reduction of friction: magnesium stearate |
| Dyes | Color: iron oxides, indigocarmine |
| Flavor Corrigents | Flavor enhancement: saccharin |
| Coating agent | Production of film-coated tablets: cellulose derivatives such as hydroxypropylcellulose |
Divisibility
See under divisibility of tablets Detailed information.
Advantages
Tablets can be taken quickly, easily, and discreetly. Unlike liquid medicines, they have a longer shelf life. They require only small packaging, can be stored easily, and contain a defined amount of the active ingredient. Tablets can be produced inexpensively in large quantities.
Disadvantages
Swallowing tablets can be a problem for children, patients with swallowing difficulties, and the elderly, among others. The dose cannot be adjusted individually, or only with restrictions – this, for example, in contrast to drops or other liquid medicines. In addition, the active ingredient must be available orally and the effect is delayed.
How big and heavy are tablets?
Small tablets are only about 100 mg (0.1 g), medium tablets are about 200 to 500 mg (0.2 to 0.5 g), and large tablets are up to about 1300 mg (1.3 g). The length varies in the range from about 0.5 cm to over 2 cm. These are approximate values. Of course, density, height and width also play a role.
Different types of tablets
Today, there are numerous varieties:
- Non-coated tablets
- Coated tablets: Coated tablets, film-coated tablets
- Effervescent tablets
- Tablets for the preparation of a solution for oral use
- Tablets for the preparation of a suspension for oral use
- Melting tablets
- Tablets with modified release of active ingredient
- Gastro-resistant tablets
- Tablets for use in the oral cavity, buccal tablets.
- Sublingual tablets
- Chewable tablets