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  1. ILC Dover
14 December 2010

Contained Blending – Flexible Enclosure Technology

The systems described here center around bin blending and V-Blender applications in oral solids dosage (OSD) manufacturing using flexible enclosures. Blending involves the controlled mixing of dry primary powder particles and excipients. The powders can range in properties and potency and, if not contained, can present cleaning and exposure issues.

Dry mixing of granular and other processing constituents includes a significantly high number of blending steps. This includes potent and highly hazardous compounds, excipients, and materials such as lubricants as processing aids. As demonstrated by the Risk-MaPP principles, both current good manufacturing practices (cGMP) and industrial hygiene (IH) needs can be met by containing the process at the source. By employing flexible containment and using the logic diagrams from the Risk-MaPP process, cleaning is minimized and the operator is protected with this engineering control. As such, processes in multi-product facilities can be safely performed without the risk of cross contamination.

Used for lab scale and production operations at multiple international pharma manufacturers, our contained blending applications take the idea of retrofits to another level. Here, existing and new equipment are supported as a tool to eliminate the risks posed by uncontrolled powder processing. At no time are the blenders’ angle of repose affected so as to change the blending performance. Note that the powder containment applications described below are based on proven designs supported for customers-based on the process equipment that they specified. ILC Dover does not have any specific ties to these equipment suppliers and does not recommend one type of blender over another. Rather, this guide depicts a sampling of flexible containment applications to a variety of styles of equipment as standard and customized containment solutions.

How does it work and what are the applications?

Three methods of flexible containment using enclosures have been applied to blenders. These include containing the entire blender in an enclosure, using an enclosure and flanges attached to the blender to separate the process and technical areas, and charging and offloading a blender with an enclosure attached to the valve on the blender. The enclosures are manufactured from clear ArmorFlex® 113 film that allows room light to illuminate inside the enclosure for easy viewing. This rugged film provides a safe working environment while enabling the enhancements developed through numerous installations using this flexible containment technology.

The bag-in / bag-out (BIBO) Sleeves and DoverPacs® are often used to transfer powders into and out of the enclosure. The Sleeves and DoverPacs are made from another version of ArmorFlex film and as such brings regulatory pedigree for materials of contact. The use of flexible containment allows the end user to process contained when needed or follow existing, open processing procedures when containment is not required. In both cases, cost savings are realized by modifying an existing design or using an existing piece of equipment with no modifications.

Separating the process and technical areas of the blender

In this method, flanges are added to the piece of process equipment, usually by the original equipment manufacturer (OEM). A flexible enclosure is then attached to the flange. The use of stainless steel flanges added to the blender enables the containment of the process area. This then keeps the controls, motors and other components of the technical section of the equipment away from the powder being processed to avoid contamination. The enclosure is attached to the flange and includes glove sleeves, bungee cords, and HEPA filters. These features support access to the equipment while maximizing ergonomics for operators from the 5th percentile female to the 95th percentile male.

  • Globe Pharma Blend Master V-Blender: in this application, flanges were added to an existing design that allows the attachment of the flexible enclosures. The frame is included to support the enclosure. This frame is on casters so it can be moved out of the processing suite and stored when not being operated. The overall enclosure is 58in (1,473mm) x 44in (1,118mm) x 70in (1,778mm) tall

Containing the entire blender

Pan-mounted enclosures contain the entire piece of process equipment. This is beneficial for equipment that can not be modified to use the flange mounted technology described above. The enclosure is supported by bungee cords, attached to the pan, and includes glove sleeves for access to the equipment. The enclosure ‘moves’ with the operator, as is the case with all of our flexible enclosure systems, to maximize ergonomics as noted above.

  • Chitra V- Blender: in this design, the containment is achieved by encapsulating the entire blender inside a flexible enclosure. The enclosure is of the pan-mounted style where the pan is situated on the floor of the process suite. In this case the pan is 53.5in (1,359mm) x 74.5in (1,892mm). The enclosure height is 75.5in (1,918mm). Multiple sets of gloves are incorporated into the flexible enclosure to support ease of operations when loading and unloading the blender and operating the controls. A bag-in / bag-out (BIBO) interface is included to allow materials to be passed in and out of the enclosure without breaking containment. The entire unit is supported on a frame
  • PK Blendmaster: a similar design contains the PK Blendmaster. The pan is 56in (1,422mm) x 61in (1,549mm) and the overall height is 81in (2,057mm). Operational features such as integral glove sleeves located at key process points, a BIBO canister, HEPA filters, and bungee cords are incorporated into the design
  • PK Blendmaster Yoke Blender: the Yoke Blender provides a tumble blending operation for free flowing materials in small volumes. As such, it can be cart mounted using a pan mount design. The pan is mounted on a frame asembly with conductive casters. Overall dimensions of this portable system are 54in (1,372mm) x 42in (1,067mm) x 73.3in (1,861mm) tall. Standard features carried over to this design include a BIBO canister for introducing raw materials into the enclosure and passing blended product out for processing to the next step, HEPA filters and bungee cord attachment to support a range of operator heights, and integral glove sleeves at optimal processing locations

Flexible enclosure loading and offloading

By attaching a multiple groove canister directly to the valve on the blender, small volumes of powders can be charged and removed from a blender using a flexible enclosure. Typically used in lab scale and clinical development trials, this process supports processing in early stages where the acceptable daily exposure (ADE) and occupational exposure level (OEL) are often not known yet.

  • Double Cone Blender Mounted Flexible: enclosure system here a small volume of powder is charged into the blender from a bottle. In order to contain this transfer a flexible enclosure is attached to the blender. In this design a 6in (150mm) multiple groove o-ring canister is attached to the valve on the double cone blender. A custom enclosure was developed based on this process that included a bag-in / waste sleeve, an ambidextrous glove sleeve, a HEPA filter, and an encapsulated o-ring for securing the enclosure to the canister

While design characteristics may be identical to rigid stainless-steel isolators, flexible film aseptic isolators offer several advantages for careful consideration.
A pharmaceutical production line must be safely and efficiently managed above all else. If a product becomes contaminated or production is delayed, it can have...
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