Tablet coating and their related questions

Tablet coating and their related questions:

What is Tablet coating? 

Tablet coating is one of the oldest pharmaceutical processes still is existence. Coating is a process by which an essentially dry, outer layer of coating material is applied to the surface of a dosage form in order to confer specific benefits over uncoated variety.

Why tablets are Enteric coated?

The coating is designed to hold together in acid conditions and break down in non-acid conditions and therefore release the drug in the intestines.

There are three reasons for putting such a coating on a tablet or capsule ingredient:

• To protect the stomach from the drug. 
• To protect the drug from the stomach.
• To release the drug after the stomach e.g. in the intestines

What is a film coated tablet?

A film coating is a thin polymer-based coat applied to a solid dosage form such as a tablet. The thickness of such a coating is usually between 20-100 µm.

What is the process of coating?

A coating is a covering that is applied to the surface of an object, usually referred to as the substrate. The purpose of applying the coating may be decorative, functional, or both.

What is the purpose of an enteric coating on a tablet?

An enteric coating is a polymer barrier applied on oral medication that prevents its dissolution or disintegration in the gastric environment. ... Tablets, mini-tablets, pellets and granules (usually filled into capsule shells) are the most common enteric-coated dosage forms.

Can you crush a film coated tablet?

Each of the modifications or coatings is there for a different reason and will be damaged by crushing. Sugar or film coating – surrounds the tablet to make it taste better. Crushing these types of tablets may make them to taste very unpleasant. Enteric coating – tablets with an enteric coating should never be crushed.

Working Principle of Vibro Sifter Machine

Working Principle of Vibro Sifter Machine

A vibro sifter is a simple equipment, however, its construction and working principle may be quite challenging for most people.

Before we review the working principle of vibro sifter machine, let’s discuss some essential components of this equipment:

High Quality Springs

From the images above (Parts of a Vibro Sifter Machines), you can see the sieves/screens are suspended on a spring. The main purpose of these springs include:

• Allow the entire upper section of the machine to vibrate freely
• It helps minimize power consumption
• Acts as damper; i.e. preventing any transmission of vibration to the floor

Apart from the springs, we have:

A Vibratory Electric Motor

It is this motor that causes the multi-plane vibratory motion as you can see in the video above. Remember, this motion increases the rate at which the material passes through the various sieves.

To achieve this, this equipment come with an out-of-balance weight assembly.

Screen Structures

This is where the sieves are fitted. It is these sieves that separate materials depending on their size/shape.

The screens are held in tension, making it easier for material to move in the direction of the vibration. This could be in horizontal or vertical direction.

Depending on the type of material you wish to process, it is possible to adjust the screen motion precisely to the performance requirements.

That is, a single machine can achieve both aggressive and gentle material separation.

The screen structure uses the FDA approved seals to prevent cross contamination of the products in different sieves.

Outer Structure/Casing

The structure is made from stainless steel. It confines the product to be processed to a desired size and finesses.

For easy mobility, the structure has nylon casters.

Hopper Lid

It confines the material, keeping both the machine and surrounding environment from dust.

How a Vibrating Sifter Works

First, I want you to review the image below:

 

Image illustrates the movement of the various particles of material being separated in a Vibrating Separator

Basically, the whole process in the image above can be summarized as:

• Feed the material you intend to separate through the hopper (the small hole at the top of the vibrating separator).
• Ensure the cover, screen structure and the base frame is tightly secured with the clamping rings.
• Power the machine from the mains and switch it on
• The vibrating motor will be energized causing a vibratory motion due to the out-of-balance weight assembly.
• The screen/sieve will begin to vibrate. Material fed to the hopper will then travel across sieves depending on the particle size.
• Material travels in a controlled pathway and exits the system through the discharge system.
• Depending on the design of the vibrating sifter, you can use the machine for:
• Classifying particles for the case of multi-deck
• Scalping or sifting for the case of a single deck

As you can see, the working principle of a vibrating separator is simple and easy to understand. Of course, every machine comes with a simple to understand manual or guide.

Remember, when shopping for these equipment, you need to go for one that guarantees quality production process.