Silica Gas-Plasma Enhances Blow/Fill/Seal Packaging

Silica Gas-Plasma Enhances Blow/Fill/Seal Packaging

John Haystead

New York, NY–Healthstar Inc. (Quincy, MA) has formed a strategic partnership with Polar Materials (Pennsville, NJ) to exclusively incorporate that company`s glass-coating, plasma technology with the blow/fill/seal (B/F/S) packaging expertise of Healthstar Pharmaceutical Services, Inc. (Riviera Beach, FL). Announced at the Interphex USA trade show, the combined “super-barrier” process provides a new B/F/S packaging option with enhanced gas, moisture and flavor barriers over standard polymers, thus extending product shelf life.

B/F/S technology has been used for some time to hermetically package many types of liquids, including certain types of clean or sterile products. It has not seen wider use, however, because the plastic materials used in B/F/S are relatively permeable to oxygen and moisture, including water vapor, inks and adhesives. Because of this shortcoming, some B/F/S-packaged products such as respiratory therapy and ophthalmic sterile products have required further packaging in foil “overpouches.” Plasma technology, on the other hand, is a proven process in the food-packaging industry used to coat sheets of packaging material to give food products extended expiration dates and enhanced-freshness.

What is novel about the Healthstar/Polar Materials approach is that by using gas-plasma technology, the exterior of a B/F/S container can be modified with enhanced barrier properties, after it has been filled, and without modifying the interior of the container. Because that portion of the container that comes into contact with the product remains unchanged, no new potential materials-compatibility problems are introduced by the process. Polar materials has invested roughly $18 million over the last 10 years to develop this technology.

The process involves placing the filled, B/F/S containers in a vacuum chamber and exciting them with a plasma energy source, either microwave or RF, which essentially removes a portion of the outer molecular layer of the polyethylene or polypropylene material generating an “ion-hungry” surface. The carrier-gas, containing the coating compound, in this case organic silica material, then reacts and bonds with this layer under controlled-temperature conditions (ambient or slightly above). To increase the effectiveness of the barrier, the process can be repeated to add multiple layers of barrier compound, between 50-200 Angstrom thicknesses of material in most cases. The required thickness is determined during the process-development phase of each product. The plasma chamber is then evacuated and the containers passed on for whatever printing or labeling the customer requires.

To minimize the amount of time between the forming and filling of the B/F/S containers and the application of the protective plasma process, the plasma units should be located in close proximity to the B/F/S machines. At Healthstar`s facility, although the B/F/S machines are themselves localized-control environments, they will operate within a Class 100 cleanroom, with the plasma chambers installed right outside. As the bottles exit the cleanroom, they will immediately enter the plasma chamber.

Healthstar CEO, William Grabowski says that, as a technology company, its philosophy is to expand the type and range of products which can be manufactured using B/F/S. “Most of our programs start at the R&D level as cooperative ventures with our customers. Obviously, we are going to have some FDA work to do with each one, but at least one customer is already heading down this route.”

The initial applications being targeted by Healthstar are pharmaceutical and medical device packaging. Harold Baseman, HealthStar Pharmaceutical`s Vice President of Contract Manufacturing, believes the first products to come out with the new packages will probably be those already approved for standard B/F/S containers, such as respiratory therapy or sterile ophthalmic solutions. “Since these B/F/S products are already in the marketplace, the approval process should be easier,” says Baseman, although he points out that the gas-plasma process “opens the door to many new applications for B/F/S such as other pharmaceutical, biotech and blood products, as well as a number of future advanced organic-synthesis products.” According to Baseman, the process will add between 1-2 cents to per-unit costs, but perhaps less in significant volumes. The increased pricing will largely be to cover the amortization costs of the necessary capital equipment.

According to Baseman, Healthstar is currently negotiating with two pharmaceutical companies interested in sponsoring a plasma-B/F/S package development and approval process for one or more of their products. “You should expect to see these products available in 12-24 months depending on how fast the approvals go through,” he says.

Healthstar ultimately expects to handle 75 percent of the plasma-B/F/S pharmaceutical-product processing at their own contract manufacturing facility in Riviera Beach, FL, which they plan to expand to handle demand. The remaining 25 percent would be done by customers at their own sites using Healthstar/Polar Materials equipment. The company has also already had quite a bit of interest from both the food and cosmetic industries, the latter offering a potentially lucrative business opportunity in the packaging of fragrance samples. Beverage containers are one possibility in the food industry, and Bill Grabowski notes that the FDA has already approved plasma technology for use in films for flavor retention in food packaging. Baseman observes, that since many of these types of applications would probably not require the same level of cleanroom environment for the process, they should also be cheaper to implement.

Parenteral Possibilities

Although Blow/Fill/Seal packages are already approved in Canada and Europe for packaging certain parenteral or injectable drugs, to date, the FDA has not approved them for this use in the U.S. “Companies outside the U.S. are often more willing to try new technologies because of concerns over how the FDA will react to any new process,” says Baseman. He believes, however, that B/F/S will eventually be approved for use with parenteral drugs in the U.S. as well.

Recently, there has been a growing interest from both industry and the FDA to use B/F/S to package injectable products. One reason is that the FDA is also concerned about the perceived limitations of conventional aseptic processing using pre-formed bottles in cleanroom environments. This has led to a push toward isolator technology and therefore toward B/F/S because it eliminates human contamination from the equation. Says Grabowski, “interest in the process has been worldwide. One major European pharmaceutical company has already begun R&D work with us on a particular product, and we have not found a single pharmaceutical company that is already doing B/F/S that is not also interested in this technology.”

Baseman acknowledges that incorporating a plasma process will add a further complication to the FDA approval process noting that, “as with any new technology, there will be a lot of questions, but for many products, B/F/S packaging would not be possible without it.” Nevertheless, he expects to see parenteral products approved for B/F/S within the next 1-2 years, some of these incorporating plasma coatings “where necessary and appropriate.” n


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