Skip to main content

Renin Angiotensin Mechanism.

Tablets: Manufacturing Defects.

1.Capping & Lamination:

  • Complete or partial loss of top and bottom crowns of a tablet from the main body is called capping. 

  • The separation of a tablet into two or more distinct layers is called lamination.

  • These problems occur immediately after compression, however may occur after several hours or days.

Causes:

1. Air entrapment.

2. Deep concave punch.

3. Claw formation of Punch.

4. Wear ring formation in die wall.

5. Incorrect setting of the press.

6. Compression of too dry material

Solutions:

1. Precompression

2. Reduction in speed of machine.

3. Reduction in final compression force.

4. Using flat punches.

5. Using hygroscopic materials to maintain proper moisture level eg. - PEG-4000 and Methyl Cellulose.

2.Picking & Sticking:

  • Surface materials from a tablet that is sticking to the punch and being removed from the tablet surface is picking.

  • Sticking refers to tablet materials adhering to the die wall.

  • When sticking occurs, additional force is required to overcome the friction between the tablet and die wall during ejection. 

Cause:

1. Picking occurs when punch tips are engraving or embossing. Small enclosed areas in letters A.

2. Wear and tear of the machine.

3. Improper cleaning before starting the batch.

Solutions:

1. Periodically checking and changing of punches and dies.

2. Proper cleaning and maintenance of the machine before batch operation.

3.Mottling:

  • It is an unequal distribution of colors on a tablet.

Causes:

1. Use of a drug whose color differs from tablet excipients.

2. Use of a drug whose dehydration products are colored.

Solutions:

1. The use of colorant may solve the problem but can create another Problem.

A dye can cause mottling by migration to the surface of a Granulation during drying to overcome this difficulty. Change the Solvent system, reduce drying temperature.

2. Disperse a dry color additive during powder binding steps.

4. Weight Variation:

  • Variation of tablet weight also causes variation of active medicaments, which changes the bioavailability.

Causes:

(a) Granule size & size distribution:

  • Variations in the ration of small to large granules and difference in granule size determine how the void space between particles are filled.

  • Since volume of die cavity remain same , different proportions of large and small particles may change  the weight of fill in each die.

(b) Poor Flow:

  • The die fill process in based on a continuous and uniform flow of granules from the hopper through the feed frame.

  •  When the granulation does not flow uniformly some dies are incompletely filled.

  • Dies are also not filled properly when machine speed is in excess of granulations flow capability.

  • For correcting poor flow the addition of a glidant such as talcum or colloidal silica may be helpful.

(c) Punch Variation:

  • When length of lower punches is unequal, the fill in each die varies which causes weight variations of tablet.

(d) Poor Mixing:

  • Some times lubricants and glidants are not thoroughly distributed.

  • The flow of particles then impaired and the granules do not  move efficiently into the dies.

5.Hardness Variation:

  • Hardness depends on the weight of materials and space between upper and lower punch at the moment of compression.

  •  If the volume of materials and distance between the punches varies hardness also alters.

6.Double Impression:

  • This involves only punches that have monogram or engraving.

  • If the monogram present in upper punch, slight rotation of punch after precompression produce double impression. If monogram present in lower punch after compression is over lower punch move slightly downward to free the tablet and produce double impression. This problem can overcome using non-rotating cam track.

That's all for today if I have missed any important one kindly comment bellow, Thank U.

Solve MCQs on Manufacturing defects of Tablets:     

Labels:

Popular posts from this blog

Rate of Drying Curve.

  Definition Drying is defined as the removal of liquid from a product usually with application of heat. Rate of Drying Curve. Drying process can be divided into three periods Initial Adjustment Period. Constant drying rate period. First falling drying rate period. Second falling rate period. Initial Adjustment Period (A-B): Also called the “ Heating up” period . In this period the substance gets heat and increases in temperature. Drying has not yet started. Constant drying rate period (B-C): During this period the temperature of the solid and the rate of drying remain constant. The moisture evaporating from the surface is replaced by water diffusing from the interior of the solid at a rate equal t o the rate of evaporation.  The moisture content at the end of constant rate (point C) is referred to as the critical moisture content (CMC).  At CMC, dry spots start appearing and drying rate starts falling . First falling drying rate period (C-D): This period is also called ...
Read more

Heat Exchangers and Heat Interchangers.

  In pharmaceutical industries many types of equipments are used for transfer of heat, they can be classified as follows, Heat Exchangers. Heat Interchangers. Heat Exchangers: These devices are used for transferring heat from a fluid (Hot Gas or Steam) to another fluid (Liquid) through a metal wall. Heat Interchangers: These devices are used for transferring heat from a One liquid to another liquid or one gas to another gas through a metal wall. HEAT EXCHANGERS; The equipment used for heat transferring are known as heat exchangers. Some of the processes that involves heat transfer in pharmaceutical industries are: Preparation of starch paste (in steam jacketed kettle). Crystallization. Evaporation. Distillation.  Classification of heat exchangers On the basis of transfer of heat, heat exchangers are classified as: Direct transfer type:  The hot and cold fluids are separated by a metal wall through which the heat is transferred from hot fluid to cold fluid. E.g. shell and ...
Read more

Flash Distillation.

  Principle: When a hot mixture is allowed to enter from a high-pressure zone into a low pressure zone, the entire liquid mixture is suddenly vaporized. This process is known as flash vaporization .  During this process, the chamber is cooled.  The less volatile fraction is condensed and the more volatile component remains in the vapor phase .  This process requires time, hence liquid and vapor are kept in intimate contact until equilibrium is achieved. Flash distillation is also called equilibrium distillation because separation of two liquids takes place when liquid and vapor phases are at equilibrium. Equipment used for Flash Distillation: Construction: It consists of a pump, which is connected to a feed reservoir.  Pumps help in pumping the feed into the heating chamber.  The heating chamber is heat supplied by steam.  The other end of the pipe is directly introduced into the vapor-liquid separator through a reducing valve.  The vapor outlet...
Read more