Tablets consist of active ingredients and excipients in the form of solid dosage. Now days we can find tablets in many varying shapes and sizes few are very attractive to but precise care is taken while manufacturing. Tablets are preferred worldwide due to its ease of consumption and carrying capacity.
Coating of tablet is done to achieve functional improvements like:
- Improve the handling capacity
- Make the tablet packing and transportation easy
- Helps in improving life of tablet and maintaining the shape
- Protects the ingredients and excipients
- Control the release of drug in intestine
As per the book of Grahem Cole, John Hogan and Michael Aulton Title “Pharmaceutical Coating Technology” below are few more interesting reasons ‘Why Coating Tablet?’: The core contains a substance which imparts a bitter taste in the mouth or has an unpleasant odour.
- The core contains a substance which is unstable in the presence of light and subject to atmospheric oxidation, i.e. a coating is added to improve stability.
- The core is pharmaceutically inelegant.
- The active substance is colored and migrates easily to stain patient’s clothes and hands.
- The coated tablet is packed on a high-speed packaging unit. The coating reduces friction and increases the production rate.
- To modify the drug release profile, e.g. enteric coating, sustained release coating, osmotic pumps, etc.
- To separate incompatible substances by using the coat to contain one of them or to coat a pellet which was previously compressed into a core?
Tablet Coating is defined as a process by which an essentially layer is applied. The process of coating involves primarily 3 components or Stages: -
- Raw tables chemical property
- Solvent/Solution which will be on the Tablet
- Coating Equipment
There are 3 main type of coating processes:
- Sugar coating:
The various sequential steps involved in sugar coating are:
- Colour Coating
- Film coating:
A film coating is a thin polymer-based coat applied to a solid dosage form such as a tablet, granule or other particle. The thickness of such a coating is usually between 20 and 100 µm.
Film-coating formulations usually contain the following components:
- Enteric coating:
The properties of enteric coating material are:
- Compatibility with most of the coating solutions
- Non toxicity.
- Low cost.
- Ease of application
- Formation of continuous film
- Resistant To gastric fluids.
We try taking up one by one technique in details in upcoming blogs, We at KERONE as involved in providing quality engineering solution to various pharmaceutical organization.