Gas detectors help with drug tablet coating thickness

Sensitive detectors, from Minneapolis-based Sensor Electronics, monitor ethanol gas concentrations in the exhaust streaming from the coating machine.

09/26/2011


Gas detector (white) looks for leaks inside the cabinet holding the mechanical system operating the sprayer and tumbler. Besides showing actual ethanol levels in LEL percentage, the detector has LEDs that glow green/amber/red, reflecting any increase in ethanol intensity. Courtesy: Sensor ElectronicsSophisticated gas detectors help a pharmaceutical manufacturer, Paddock Laboratories, measure coating thicknesses on drug tablets. The sensitive detectors, from Minneapolis-based Sensor Electronics, monitor ethanol gas concentrations in the exhaust streaming from the coating machine.

While the detectors protect plant personnel, said John Levasseaur, production engineer, Paddock Laboratories, using them to monitor coating thickness is especially intriguing.

Technical engineer John Levasseur inspects mounting for spray head feeding ethanol-based tablet coatings. Duct opening (lower left) carries exhaust gases. Courtesy: Sensor ElectronicsTablet bases are fed into a twirling tumbler where a small-bore feeder sprays a bonding mist of the ethanol carrier, plus a color tint, a lubricant (for easier swallowing), or the drug itself. Depending on the coating, the tablets are tumbled from 30 minutes up to 4 hours, with close monitoring of the ethanol feed, temperature, and humidity.

The ethanol concentration in the exhaust is directly proportional to the coating thickness on the tablets. A too-high ethanol level means a too-thick coating, so the spray mist ratio is decreased. The ethanol proportion in the exhaust then verifies the feeder setting.

Tablet-filled basket tumbles inside stainless-steel housing; ethanol gas carries tin/lubricant/drug coating feeding through arm extending into basket. Depending on coating, tumbling times range from 30 minutes to 4 hours. Courtesy: Sensor ElectronicsThe gas detectors do double duty. Ethanol is explosive, so if ethanol levels in the exhaust duct reach a preset LEL (lower explosion limit), then the detector triggers alarms to warn workers. If the ethanol concentration continues to rise, the gas detection system turns on fans to flood the area with outside air.

Paddock Laboratories concentrates on niche markets for generic drugs. “But with any generic drug—or any drug, for that matter—reliability is the key. Closely monitoring ethanol levels in our coating process helps us maintain that reliability,” Levasseaur said.

- Tom Probst, corporate communications, Sensor Electronics Corp.

www.sensorelectronics.com



The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by Control Engineering subscribers. Vote now (if qualified)!
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
This eGuide illustrates solutions, applications and benefits of machine vision systems.
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Maximize ROI with integrated control system approach; Microcontrollers vs. PLCs; Power quality; Accelerate and rewire IIoT; Traits for excellent engineers
HMI effectiveness; Distributed I/O; Engineers' Choice Award finalists; System Integrator advice; Inside Machines
Women in engineering; Engineering Leaders Under 40; PID benefits and drawbacks; Ladder logic; Cloud computing
Programmable logic controllers (PLCs) represent the logic (decision) part of the control loop of sense, decide, and actuate. As we know, PLCs aren’t the only option for making decisions in a control loop, but they are likely why you’re here.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This article collection contains several articles on how advancements in vision system designs, computing power, algorithms, optics, and communications are making machine vision more cost effective than ever before.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
Cloud, mobility, and remote operations; SCADA and contextual mobility; Custom UPS empowering a secure pipeline
Infrastructure for natural gas expansion; Artificial lift methods; Disruptive technology and fugitive gas emissions
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Jose S. Vasquez, Jr.
Fire & Life Safety Engineer; Technip USA Inc.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me