Liquid Manufacturing: A Fluid Way to a Finished Product

by Mark Sysler

Liquid contract manufacturing has become a mainstay of the nutritional business. Competition has intensified and, along with supplement contract manufacturing, it has become high on the GMP (good manufacturing practice) required list. FDA looks as closely at finished liquid supplements as it does tablets or capsules. Competition in this category is good for the customer and good for the industry. Headlines are always filled with the stories of poor manufacturing procedures resulting in recalls, health hazards and drama. Understanding the manufacturing process will elucidate the complexities and the time involved to get to the finished product.

The key to good liquid manufacturing is preservatives, or a system that will prevent the growth of microbiological organisms, including yeast and mold. Proper formulations provide the path to the right combinations of ingredients and keep the product in liquid form. Having a liquid product fall out of solution once delivered to the customer can be disastrous. The final portion to be addressed is stability, so what is on the label continues to be in the liquid to the end of the expiration date. These challenges need to be addressed when developing and manufacturing a liquid supplement even before the complexities of sourcing materials, compounding, bottling and packaging. Then add quality control (QC) and GMPs to the equation.

The formulation process takes into account the ingredients required, the basis of the liquid, the preservatives required and also the flavoring. Each of these dynamics has to fit into the finished product to work. Powders can leave gritty tastes, and oils usually dont mix with water. The dosage also needs consideration because what you can get in a teaspoon may not fit into a one ml dose. The basis of the liquid, such as water, glycerin, juices or alcohol, plays a key role in designing the preservative system for that product.

Major factors in the preservative system include pH levels, acceptable preservatives and the liquid basis (water, glycerin, alcohol, etc). There are many preservatives to choose from, such as methyl and propyl parabens, sorbic acid, potassium sorbate, calcium sorbate, all the benzoates and others, which generally need a low pH to be effective. However, remember pH levels can affect taste dramatically, so a delicate balance needs to be achieved between pH and preservatives. Experience and knowledge of the preservatives and pH by the formulator can make a big difference in the final product. Its almost an art form. And since microbiological organisms love to grow in liquidseven more so than powdersit is essential to have the preservative system in place.

Stability of the product requires the ingredients used do not degrade and that the label claim remains consistent until the expiration date of the product. Shelf life can range from six months to three years, depending on the ingredients and the effectiveness of the preservatives. Flavor, an important aspect of the final product, can lose stability quickly. Natural flavors tend to darken and lose potency quicker than artificial flavors. Appropriate stability chamber testing helps to determine projected shelf life of a product. Once production starts, real time testing should be done at six months, one year, 18 months and then every year after that up to three years.

Heading into Production

Once the formulation considerations have been addressed, its time to head into manufacturing.

At the starting line, the manufacturer must have efficient equipment on hand to make the product(s) and protocols and procedures in place. Material acquisition involves not only reviewing documents upon arrival, but can also involve taking samples and having appropriate testing done such as HPLC, or other technical evaluation before the QC department can release a raw material for use in production. If a formulation has 20 to 30 ingredients, this procedure needs to be done as many timesclearly a time-consuming and costly process.

Materials and components are then pulled, weighed or counted, and sent to manufacturing. Production time needs to be determined, and the manufacturing run needs to be scheduled. Some finished products require heating and then cooling to add ingredients. This multi-step process adds to the production time. Multi-step processes can lead to issues in production if the process is not carefully followed.

QC must then test and approve the manufactured material made before it is put into the finished product/bottle. This additional procedure ensures the product made is the product ordered. Once the liquid is filled into the bottle, the product should be tested for compliance with spec and micros. Not to do this entire procedure results in no traceability and poor products, and may present a health hazard to the consumer. This basic procedure is consistent for all companies and products.

There is a cost and time factor that accompanies all the requirements for GMPs and QC compliance. More testing is expensive and additional labor costs are inherent with compliance. However, this aspect of manufacturing is not optional. It is demanded by customers and required by federal regulations. And in liquid manufacturing, the element of microbiological contamination is greater than in dry manufacturing. Therefore, adherence to the GMPs is required.

Mark Sysler is the vice president of sales with Natural Products Packaging , a Hauppauge, NY-based contract manufacturer; NPP is has been GMP certified by NSF International.