What is tablet?
Tablet is a solid dosage form in
which powder, crystalline or granular form of drug is compressed in a disk or
molded. It is the most frequently used means of administering a drug. Most of
the tablet is administered orally. However, the tablet for application as
implant, solution, vaginal use, and external use are also available.
Oral tablet is designed to release the drug within the gastrointestinal tract for absorption into the circulation or more rarely for a local effect. It is usually swallowed or dissolved in water before taking.
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Oral tablet is designed to release the drug within the gastrointestinal tract for absorption into the circulation or more rarely for a local effect. It is usually swallowed or dissolved in water before taking.
The molded tablet is softer than the
compressed tablet. The molded tablet dissolves rapidly when administered by
placing under the tongue. The compressed tablet offers many advantages to the
patient, the prescriber and the manufacturer. There may be single or multiple
compressed drug following oral administration.
To make the tablet well acceptable
to the patient and easier to swallow, the tablet is prepared in different
shapes and sizes. The tablet is usually discoid in shape. It may be available
in other shapes such as round; oval, triangular or elliptical .The upper and
lower surfaces of a tablet may be flat or convex. The tablet may be marked with
a line across the surface so that it can be broken into halves easily.
Sometimes the tablet may be marked with trade name with or without the amount
of the active ingredient.
Types of tablet:
Chewable tablet-The tablet which is intended to be broken and chewed in
between the teeth before ingestion. Antacid and vitamin tablets are usually
prepared as chewable tablets. It is given to the children who have difficulty
in swallowing and to the adults who dislike swallowing.
Effervescent tablet-The tablet that contains acid substances and carbonate or hydrogen carbonate that react rapidly in the presence of water to release carbon dioxide. Sodium bicarbonate, citric acid and tartaric acid are added to the active ingredients to make the tablet effervescent. This preparation makes the tablet palatable.
Effervescent tablet-The tablet that contains acid substances and carbonate or hydrogen carbonate that react rapidly in the presence of water to release carbon dioxide. Sodium bicarbonate, citric acid and tartaric acid are added to the active ingredients to make the tablet effervescent. This preparation makes the tablet palatable.
Lozenge tablet-The tablet that is intended to produce continuous effect on
the mucous membrane of the throat. There is no disintegrating agent. The
quality of the binding agent is increased so as to produce slow dissolution.
Suitable sweetening (sugar), coloring and flavoring agents must be include in
this formulation. Gum is used to give strength and cohesiveness to the lozenge
and facilitating slow release of the active ingredient.
Soluble tablet-The tablet that dissolves completely in liquid to produce
solution of definite concentration. Mouth wash, gargle, skin lotion, douche;
antibiotic, certain vitamins, and aspirin are given in this formulation.
Sublingual tablet-The drug which is destroyed or inactivated within the
gastrointestinal tract but can be absorbed through the mucosal tissue of the
oral cavity is usually given in this formulation. The tablet is required to be
placed below the tongue for the slow release of drug. But for immediate effect
some medicaments are formulated in such a way to dissolve within 1 to 2
minutes. Nitroglycerin is prepared in this formulation.
Enteric coated tablet-Some drugs are destroyed by gastric juice or causes
irritation to the stomach. These two factors can be overcome by coating the
tablet with cellulose acetate phthalate. This polymer is insoluble in gastric
contents but readily dissolves in intestinal contents. So there is delay in the
disintegration of dosage form until it reaches the small intestine. Like coated
tablet, enteric coated tablet should be administered in whole form Broken or
crushed form of the enteric coated tablet causes destruction of the drug by
gastric juice or irritation to the stomach. Enteric coated tablet is
comparatively expensive.
Film coated tablet-The tablet that is covered with a thin layer or film of
polymeric substance which protects the drug from atmospheric conditions and
mask the objectionable taste and the odor of drug.
Implant-A small tablet that is prepared for insertion under the skin
by giving a small surgical cut into the skin which is stitched after the
insertion of the tablet. This tablet must be sterile one. The drug used in this
preparation is usually water insoluble and the tablet provides a slow and
continuous release of drug over prolonged period of time ranging from 3 to 6
months or even more Contraceptive tablet is formulated as implant.
Sugar coated tablet-The tablet that contains active ingredient(s) of unpleasant
taste may be covered with sugar to make it more palatable. This type of tablet
should be administered in whole form, otherwise the patient will experience the
unpleasant taste of the active ingredient.
Modified release tablet-Modified-released tablet is either uncoated or coated. This
contains special additives or prepared by special procedure which, separately
or together, is intended to modify the rate of release of the drug into the
gastrointestinal tract. It prolongs the effect of drug and also reduces the
frequency of administration of drug. Several drugs are available in modified
release tablet such as indomethacin.
There is another term popularly
known as pill. Once the people’s idea was to use of pill in every ill. Now days
the term has been only used in contraceptive preparations such as combination
pill, minipill, and morning after pill.