Simulate, Test Large Mixing/Granulation Processes on Just 100 Grams of Material

At the InterPhex pharmaceutical manufacturing exposition in New York (April 20–22), equipment distributor AC Compacting Presses (North Brunswick, NJ) launched two new product lines designed to cut down on early development costs: a high-shear mixer/granulator from Pro-C-ept (Zelvat, Belgium), and a mixer torque rheometer from Caleva Processing Solutions (Sturminster, UK). Both products address the needs of pharmaceutical developers to analyze and work on batches as small as possible to avoid wasting material.

Waste Not, Want Not
Advantages of the Mi-Pro
Mi-Pro Specifications
Benchtop Rheomter

Waste Not, Want Not (Back to Top)
In the early stages of drug development, often only limited quantities of a drug are available for granulation testing. For oral dosage forms, where granulation methods prevail, the minimal loading in commercially available high shear granulators is between 1–3 kg. Most systems operating even at this level, however, carry a severe tradeoff in the amount and quality of information they provide.

The Mi-Pro high-shear mixer/granulator from Pro-C-epT promises to cut the amount of material required for granulation testing by a factor of from 10 to 30. The Mi-Pro can process as little as 100 grams of sample but "provides as much information on that sample as you can get from an entire batch," according to Robert Fortier, VP of Engineering at AC Compacting Presses.

"As a rule, any combination of equipment that processes samples as small as 100 g gives you only rudimentary information," Fortier told Pharmaceutical Online. "In most cases, the information is so meager that engineers don't use these products. The Mi-Pro gives engineers precise granulation data—everything they need—from very small batches. The advantage is that you can now get all the data you need in very early stages of drug development, or with very small amounts of potent or expensive material."

Fortier gave as an example a high-shear granulation and drying process, where engineers might look for mixing torque, mixing speed, chopping speed, binder addition and binder volume, and absolute volume of total binder. "These parameters need to be controlled precisely," Fortier said, "but it was never possible to get this much information from such small batches."

Mi-Pro features a glass bulb through which operators can observe such processes as granulation (both low- and high-shear), mixing, spheronization, homogenization, suspension, de-aeration, emulsion, vacuum and microwave processing, drying, heating, melting, extraction, coating, and gas injection.

Advantages of the Mi-Pro (Back to Top)

• Works with powders or liquids.
• Modular construction for ease of upgrade from basic mixer configuration to a complete microwave vacuum processor with control and data acquisition capabilities.
• Processes may be simulated and controlled using the same parameters as the actual production process, leading to simple scaleup and accurate specs for production equipment.
• All components can be disassembled and washed.
• Mixing parameters include impeller speed, chopper speed, impeller torque, product temperature, and liquid dosing flow rate.
• Vacuum processing measurements include pressure in the bowl, pressure dropover vacuum filter, and solvent recovery.

Mi-Pro Specifications (Back to Top)

Maximum bowl volume.............1700 ml
Impeller speed..........................0–1500 rpm
Impeller torque.........................14 Nm
Chopper speed.........................0–4200 rpm
Chopper torque........................0.33 Nm
Dimensions..............................900 x 400 x 400 mm
Typical granulation mass...........300 g
Quick connect motors, quick clamp release

Benchtop Rheomter (Back to Top)
AC has also become the exclusive distributor of a benchtop rheomteter, the Model MTR (mixer torque rheometer) from Caleva Processing Solutions Ltd., a UK-based engineering and instrumentation firm. Caleva designed the MTR for process industries where the rheologic properties of wet masses need to be determined, including pharmaceuticals, food processing and baking, cosmetics, pesticides, and agrochemicals. Like the Pro-C-ept mixer/granulator, the MTR's stingy material requirement frees up valuable pharmaceuticals for animal and clinical testing. Caleva's mixer torque rheometer uses intermeshing contra-rotating paddles: The secondary paddle rotates at twice the primary paddle's speed, shearing the mix, while the reaction of the mixing bowl is continuously monitored, via a torque arm, by a calibrated dynamometer.

For more information: Robert Fortier, VP of Engineering, AC Compacting Presses, 1577 Livingston Ave., North Brunswick, NJ 08902-7266. Tel: 732-249-6900. Fax: 732-249-6909.

By Angelo DePalma