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2024-03-11

One of the applications of Proportionair proportional valve in pharmaceutical industry-pill coating

The pharmaceutical industry requires precise control in all applications. Proportion-Air's closed-loop technology ensures the accuracy of various processes, including: regulation of atomizing air in pill coating applications, control of pneumatic diaphragm pumps, pill coating, etc.

Pills are usually coated with a polymer or polysaccharide coating to extend their shelf life and make them more attractive and easier to swallow. Sometimes the coating contains certain controlled release drugs.

When the pills are shaken in the vat or coating pan, our device controls the pressure of the spray by controlling the air atomization (separation into smaller-sized droplets) on the pills. The device can control the pressure of a nozzle with a fixed orifice to produce a perfect flow (such as 30 psi) using pressure or flow. Under pressure, the coating may accumulate in the nozzle over time and cause the flow to decrease-but our product ensures that you get the same pressure when there is no opening at all. Through flow control, when accumulation occurs, our equipment will increase the flow through the nozzle to maintain a consistent spray.

Our systems can accommodate vacuum or positive pressure to apply coatings, as well as micro-mist nozzles for fine atomized sprays. The results are precise and repeatable-extremely important in such a highly regulated industry.

In the pharmaceutical industry, pill coating is one of the final steps before product packaging and shipping. Not all pills have a coating, but any pill that may have an irritating effect on the stomach is usually coated with a substance that only dissolves in the small intestine. Sometimes the pills are coated to make swallowing easier or for branding purposes only.
Regardless of the reason for pellet coating, consistent pressure and/or flow control is required to accomplish the task. Flow can be used very effectively in spray applications to overcome any build-up in the nozzle to maintain consistency.
However, in this application, QB3 is used to control the pressure of nitrogen to the coating fluid. The speed sensor is measuring the speed of the conveyor belt and providing this information to the controller. The controller then calculates a command signal to QB3 based on the speed of the conveyor belt. This keeps the spray consistent regardless of the speed at which the pill is moving.