For years, pharmaceutical processors have been using Admix equipment for rapid mixing and to minimize foaming in their formulations. Two culprits that have been used together are various grades of Methocel® (Hydroxypropyl Methylcellulose/HPMC, or Hydroxy Propylcellulose/HPC) and polyvinylpyrrolidone/PVP including the trade names Kollidone®, Povidone® and Plasdone®.
These two powders are used separately or in conjunction for a wide variety of uses, including binders in tableting, in formulations for tablet coatings, in granulation operations, and as film-forming agents. When dispersed and hydrated in water, these ingredients often cause excessive foaming) in most mixing operations. These ingredients benefit from high shear mixing, which offers completely hydrated product with no lumps, faster batch times, and less air entrainment, but foam can be a challenge for a batch mixer, taking up to a day for it to subside unless subjected to a vacuum to de-aerate it faster.
Several of our pharmaceutical customers have had great success with our powder induction line, specifically the Fastfeed powder induction system and VacuShear vacuum pump liquid processor. In recent on-site mixer trials and free lab tests, these mixers were tested over time to determine the best processing solution and both were successful at significantly reducing or totally eliminating the foam, rapidly hydrating the powders with no lumps, and finishing batches in minutes rather than hours. These tests ultimately led to equipment installations, complete with our process assurance warranties guaranteeing scalability.
The FastFeed inducts these powders quickly at around 5-10 kilograms per minute with less air entrainment and much faster than conventional agitators. Also, it instantly hydrates the powders before the slurry returns to the tank with no lumps, clumps, fisheyes, or foam.
The VacuShear can induct powders even faster 60-150 kilograms per minute, with the added benefit of a vacuum in the tank. This ability to pull a vacuum can de-aerate product in 30-40 minutes. The VacuShear is a batch-process system that can be designed to accommodate batches from 150 to 6,000 liters.
Is foaming a big issue for you? Contact us to help you eliminate foaming today!
Contributed by George Nikolopoulos