Short essay on Compressed Tablets

For making compressed tablets, it is necessary to prepare the material in a dry, granular form to render it suitable for passing through a compression machine. Following general processes are employed for this purpose.

I. Wet granulation

1. The drug or a mixture of drugs in powder form is mixed; diluent and half quantity of disintegrating agent are added. The material in the desired degree of fineness is mixed and damped with a suitable moistening agent selected with regard to its effect on the chemical and physical nature of the material.

2. The moistened material is made into granules by passing it through a sieve # 12, 16, 22 etc.

3. The granules are dried in a current of air, at a suitable temperature generally not exceeding 60 °C.

4. The dry granules are passed through suitable sieve to get uniform granules and half quantity of disintegrant, lubricant, antiadhesive and glidant are added.

5. These granules are mixed well and are suitable for compression to get the desired type of tablets.

II. Dry granulation

1. The drug or a mixture of drugs in powder form is mixed. If necessary, add a suitable inert substance to act as diluent along with half quantity of disintegrating agent and lubricant.

2. Compress the powder materials in the form of large tablets.

3. These large tablets are broken up into granules of a suitable size.

4. These granules are passed through set of sieves to get granules of uniform size.

5. The remaining quantities of disintegrant, lubricant and glidant are added and mixed well. The granules can be compressed using tablet machine.

III. Direct compression

1. The drug or a mixture of drugs in powder form is mixed. If necessary, add a suitable inert substance to act as diluent, direct compressible disintegrating agent, glidant and lubricant.

2. Pass the powder material through a suitable sieve.

3. Compress the powder materials in the form of tablets.