Weighing the Benefits of Scale Equipment
When it comes to pharmaceutical manufacturing, every machine, component and piece of equipment must work in unison
By Louis Alonzo, Territory Manager, Avery Weigh-Tronix
In any setting, the manufacturing process is like a complex puzzle, and specifying the appropriate components and equipment provides the backbone for efficient, cost-effective operations. Manufacturing is indeed a precision game, where every machine, component and piece of equipment must work in unison. In the pharmaceutical and biopharmaceutical industries, it’s even more so; products directly impact the health and well-being of the population, making precision paramount throughout the manufacturing process. In this manifestly complex manufacturing ecosystem, everything from aspirin tablets to cough syrup are expected to deliver consistent dose, form, texture and taste, producing the same symptomatic relief and health benefits pill-for-pill, tablet-to-tablet, or dose-after-dose.
Scale equipment in the pharmaceutical manufacturing setting continues to play a critical and integral role in achieving quality and consistency objectives. To achieve such consistency and quality, the precise weight of each ingredient must be assured. For instance, bench scales and check-weighers can provide a high degree of accuracy in manual operations, while load cells and indicators with advanced integration capabilities can provide an automated weighing solution. System automation effectively decreases dependence on manual monitoring, manipulation and operation, minimizing human error. By applying advanced weighing technologies to complex pharmaceutical blending and batching applications, manufacturers can enhance quality control, improve inventory management, increase throughput and reduce labor and other production costs.
High-Accuracy Manual Weighing
Bench scales and checkweighers offer pharmaceutical manufacturers versatile weighing capabilities, delivering in-line weighing or package verification prior to distribution. Providing highly accurate, legal-for-trade weighments, bench scales allow manufacturers to mix precise ingredient amounts during processing and afterward employing checkweighers to confirm package quantity. Bench scales and checkweighers are designed to accommodate fast-paced automated processes, delivering instantaneous, exact readings in numeric or easy-to-interpret graphical formats.
Bench scales and checkweighers generally feature a simple interface to facilitate use, minimizing errors and increasing production throughput. By clearly displaying Over/Under/Correct, operators can identify at a glance if products meet process requirements for simplified monitoring. Also, to meet pharmaceutical hygiene standards, many bench scales and checkweighers are fabricated of stainless steel, designed to withstand washdown conditions. In pursuit of enterprise connectivity, these scales can also be set up to print results or communicate and store data via standard protocols, delivering to users, among other things, sophisticated product traceability.
Similar to baking, when manufacturing pharmaceutical products, such as vitamins and drugs in tablet form, operators must combine measured amounts of multiple ingredients. For instance, a company that manufactures supplements and vitamins must include the exact amount of each element each time the product is produced to retain its engineered and expected characteristics. By placing a bench scale at each station on the processing line, operators have the ability to precisely measure each component prior to adding it to the mixture. Common practice typically finds users placing batch ingredients directly onto the scale until the pre-determined amount is reached, ensuring batch recipes are followed accurately each time.
Once the dose forms are packaged, checkweighers ensure each container’s weight meets the designated amount listed on the package. Once the tolerances have been inputted into the scale, operators will be able to decipher immediately whether the product meets weight requirements. For example, if a given jug of powdered supplement is placed on the checkweigher, displaying Over/Under/Accept fan graphs allows operators to determine if its weight corresponds to what is listed on its label.
Scale Systems for Automated Pharmaceutical Processing
A weight sensor, or load cell, is a steel structure with strain gauges, or electronic sensors, positioned on the outside surfaces: two sensors on the top and two on the bottom. Unsupported on one end and fixed on the other, this structure acts as a cantilever. When a load is applied on the unsupported end, the sensors detect strain in the structure and provide an analog mV/V output. This output is interpreted by indicator electronics, and the weight indicator digitally displays the strain as the load’s weight.
For pharmaceutical batching and blending applications, electronic weight sensors can be affixed to bins, tanks or hoppers holding dry or pre-mixed ingredients, effectively transforming ingredient containers into highly accurate, in-line scale solutions. As materials are placed into a container, the electrical current running through each weight sensor changes, and this altered current is brought to and combined at a junction box. From here, the collected data is sent via interface cable to a scale indicator, which converts the current to a digital weight display.
In these operations, the accompanying indicator is a key component, because it can be programmed to control filling and batching applications through bin or hopper monitoring — observing each operation until its designated container meets a user-programmed set-point. Adding weight sensors to existing packaging and batching equipment is, in most cases, straightforward and unobtrusive, and not likely to disrupt operations if installed. Similarly, sensors equipped with stainless-steel housings withstand washdown in pharmaceutical and chemical applications.