Before any drug can be manufactured, it must first be carefully formulated and developed to ensure that all its components—especially its active pharmaceutical ingredients (APIs) —will perform the desired action and produce ideal results. If the drug doesn’t contain the right balance of ingredients or the materials have been contaminated, it may not work; worse, it may cause serious harm to the patient. These reasons, among many others, make the weighing and dispensing stage a critical part of the entire pharmaceutical manufacturing process.
The pharmaceutical industry also has one of the strictest, most precise manufacturing requirements in terms of quality. This is why strict control measures and equipment protocols have to be in place in the dispensary, which is both the entry and transition points of materials going into the processing stage, to ensure both the safety of the employees and the quality of the drugs. Human workers—who can make rational decisions under otherwise confusing circumstances for machines—also continue to be an integral part of the entire manufacturing process, even as the weighing and dispensing stages have already been automated to improve operations.
Weighing and Dispensing: A Collaboration of Man and Machine
Speed and accuracy are two of the most important factors in manufacturing medicine. Hand-scooping remains to be the most common dispensing process for solids, while pumping and pouring applies for most, if not all, liquid components. With the help of modern weighing and dispensing procedures and equipment, however, these manual processes can be enhanced to ensure that the drugs produced are released to the market on time and meet the highest quality standards.
Pharmaceutical manufacturing equipment such as checkweighers are calibrated to determine even the slightest change in the predetermined weight of the ingredients. Meanwhile, linear stages in dispensing machines help the operators with the precision-control of movement and speed for accurate withdrawal and transfer of ingredients. These machines also help lower the cases of spills, leaks, and emissions that may otherwise harm the workers operating them.
On the other hand, pharmaceutical materials are weighed in extremes during the lot dispensing stage. Components like APIs, solid dose forms (SDFs), and liquids, ointments, and creams (LOCs) are usually weighed in bulk, reaching up to 2,000 liters worth of materials. Inert ingredients and excipients—like dyes, flavorings, preservatives, and binding agents—are also measured through large lot dispensing. Meanwhile, sterile injectables (SIs) and biopharmaceuticals such as cell cultures are weighed out in smaller or intermediate lots—usually from 0 to 10 kg and 10 to 50 kg—which typically already contain all of the materials needed to manufacture one batch of drugs.
Through the application of best practices in weighing and dispensing—which include product sequencing, electronic signature and batch data recording, and label printing—errors and inconsistencies may be eliminated in this stage of the drug manufacturing process.
Weighing and Dispensing at Every Stage
After the raw material staging and lot dispensing procedures, all equipment that came in contact with materials have to be cleaned thoroughly to reduce the risk of contamination and reduce operator exposure to high-potency APIs like digoxin, calcitriol, and alprazolam.
A series of other procedures follow the wash-and-preparation stage. These include low-humidity dispensing, sterile weighing dispensing, weighing of hazardous and nonhazardous materials, and warehouse waste movement, among others. Notice that in almost every other step, weighing and dispensing methods are involved—even in waste disposal. This only further highlights the importance of the careful layout, operation, and application of weighing and dispensing equipment and procedures.
With all these things in mind, it is safe to say that weighing and dispensing is the backbone of pharmaceutical manufacturing, particularly because it is the starting point of the entire process. If something goes wrong at this early stage, every material that comes into the process area may be excessive, insufficient, or already contaminated. However, if best practices and proper equipment are applied from the beginning, pharmaceutical manufacturing becomes safer and more efficient for all stakeholders.