Tablet Coaters

Tablet Coaters

Tablet Coaters sprays the liquid solution onto the surface of the tablets. The basic process consists of Coating - Drying - Discharging.

Using the spray guns based on HVLP type, the high-coating efficiency can be guaranteed. Also easy nozzle replacement offers the options of Aqueous, Sugar and Film coating.

Through the discharging chute designed for easy attachment and separation, the coating-completed tablets are automatically discharged while the pan rotates in a reversed direction.

All of the production parameters can be saved into the database, which enables the regular coating products to be consistent in quality.

Construction

Tablet coating takes place in a controlled atmosphere inside a perforated rotating drum. Angled baffles fitted into the drum and air flow inside the drum provide means of mixing the tablet bed. As a result, the tablets are lifted and turned from the sides into the centre of the drum, exposing each tablet surface to an even amount of deposited/sprayed coating.

The liquid spray coating is then dried onto the tablets by heated air drawn through the tablet bed from an inlet fan. The air flow is regulated for temperature and volume to provide controlled drying and extracting rates, and at the same time, maintaining the drum pressure slightly negative relative to the room in order to provide a completely isolated process atmosphere for the operator.

Tablet coating equipment may include spray guns, coating pan, polishing pans, solution tanks, blenders and mixers, homogenizers, mills, peristaltic pumps, fans, steam jackets, exhaust and heating pipes, scales and filters. Tablet coating processes may include sugar coating (any mixtures of purified water, cellulose derivatives, polyvinyl, gums and sugar) or film coating (purified water, cellulose derivatives).

Process

• The coating process is usually a batch driven task consisting of the following phases:
• Batch identification and Recipe selection (film or sugar coating)
• Loading/Dispensing (accurate dosing of all required raw materials)
• Warming
• Spraying (application and rolling are carried out simultaneously)
• Drying
• Cooling
• Unloading

Control

• A control system must therefore provide flexibility in the way in which accurate and repeatable control of the coating environment is achieved and will include the following features:
• Precise loop control with setpoint profile programming
• Recipe Management System for easy parameterization
• Sequential control for complex control strategies
• Secure collection of on-line data from the coating system for analysis and evidence
• Local operator display with clear graphics and controlled access to parameters