Tablets are solid dosage forms usually containing active pharmaceutical ingredient and excipients in powder, crystalline or granular form with or without diluents which is prepared either by moulding or compression process. They are solid, biconvex or flat in shape and vary in size, shape and weight which is depends on the medicaments which are used for preparation. They are also varying in hardness, disintegration; dissolution characteristics and thickness depend on their intended use and method of manufacture. Tablets are the most widely used solid dosage forms because of their advantages and popularity increasing day by day. Tablet usually contains filler, diluents, binders, lubricants, glidants, disintegrants, antiadherent, colouring agents and flavouring agents as excipients.
Advantages of tablets
Unit dosage forms with accurate, stable dose and great precision and least variability.
Most stable with respect to physical, chemical and microbiological attributes.
Cheapest oral dosage form, easy to handle, use and carry out with attractive and elegant appearance.
Cheap, easy to swallow and production does not require and additional processing steps.
Provide protection of medicaments from atmospheric conditions like air, moisture and light, etc.
Provide prolonged stability to medicaments.
Low manufacturing cost as compare to other solid dosage forms and large scale production is possible.
Administration of minute dose of drug in accurate amount.
Unpleasant taste can be masked by sugar coating.
Easy to divide into halves and quarters whenever fraction dose is required.
Formulate as a special release products such as enteric or delayed release products.
Packing and production is cheap and does not require more space for storage.
Disadvantages of tablets
Drugs which are amorphous and low density character are difficult to compress into tablet.
Hygroscopic drugs are not suitable for compressed tablets.
Drugs with low or poor water solubility, sloe dissolution, high absorbance in GI tract may be difficult to formulate.
Sensitive to oxygen drugs may require special coating.
Cost of production may be increase because of coating and encapsulation to remove bitter and unpleasant taste.
Some tablet may cause problem in bioavailability.
Difficult to formulate liquid in tablet and swallowing is difficult especially for children and ill patients.