Fine Particle Dose Impactor -FPD
Westech FPD Impactor is provides abbreviated impactor measurements (AIM). The instrument was Specifically developed to reduce unnecessary analytical input and time by eliminating the need for intermediate stage recovery, Westech’s newly developed impactor clearly supports initiatives driving implementation of a Quality by Design (QbD) approach to the invention, development and commercialization of inhaler, nasal and oral spray products in the pharmaceutical industry.
The Westech FPD Impactor is a two-stage, multi-jet impactor with a final filter incorporating a unique interlocking system (patent pending) for fast assembly and disassembly removing the need for springs or clumsy clamping mechanisms. The design is based on the Andersen 6-Stage Viable Impactor (Dr. A. A. Andersen); coated Petri dishes are used as the collection media with a cassette-type final filter holder. Advance dish and filter preparation allows for faster set up and testing.
Specifically designed to have aerodynamic cut points at 5 ?m, 1 ?m and a final filter with a flow rate at 28.3 L/min (MDI) or 60 L/min (DPI), the impactor reduces the analytical load required to determine the fine particle dose (FPD) and allows for fast screening of formulations or product without the necessity of a complete assessment of each stage of a typical multi-stage cascade impactor. The DPI system can also utilize a preseparator for particles in excess of 10 ?m.
The FPD is defined as the amount of the drug less than a specific aerodynamic size deemed capable of reaching the lower part of the respiratory tract and therefore “respirable”. FPD is calculated by totalling the drug deposited on specified stages of an impactor. For example with USP Apparatus 5 & 6/EP Apparatus E at 60 L/min-1, the FPD is understood to be the total drug deposited on stages 3 to 7 and equates to the amount of drug <4.46 ?m. In order to compare FPD results from tests operated at different flow rates or impactors, the amount of drug <5 ?m is typically calculated. This result is normally obtained from a log-probability plot. Features and Benefits
• Cutpoints at 5 & 1?m reduces data interpolation & improves accuracy
• Fewer stages reduce analytical time • Glass Petri dishes for direct recovery
• Springless interlocking system (patent pending) saves assembly time
• 28.3 and 60 L/min. flow options for DPI testing
• Rapid Results supporting a QbD approach
With the support of AstraZeneca R&D Charnwood and in conjunction with Frank Chambers (AstraZeneca), Westech has designed a new 2-stage impactor for the rapid screening of FPD removing the requirement for analyzing or measuring multiple stages from conventional, multi-stage impactors as described in various Pharmacopoeias. The impactor has been dynamically calibrated under the supervision of Dr. Ian Marshall of AEA Technology, UK.