Copley Scientific has launched two new products that enable metered-dose inhalers (MDI) testing according to methods outlined in a new USP monograph, currently in draft form. The USP monograph describes MDI testing using spacers and valved holding chambers (VHCs). These are devices used to help patients with poor coordination as well as young children.
According to Copley Scientific, its new BAC 2000 breath actuated controller and BRS 1100 breathing simulator, in combination, support closely controlled testing under the representative conditions for neonate, infant, child and/or adult patients in line with the new monograph.
MDIs provide a cheap and efficient way of delivering therapeutics to the lungs; however, patients must be able to coordinate operation of the MDI with inhalation. Coordination can be a problem in certain patient groups, especially paediatrics. In such cases, spacers or VHCs are used. These devices introduce a chamber of dead volume between the MDI and the patient’s mouth. Actuation of the MDI delivers the drug into the spacer or VHC and the patient can then freely draw the drug into the lungs by inhalation.
The patient’s breathing profile will affect drug delivery to the lungs from the spacer or VHC, as noted in the new monograph. Moreover, there is potential for variability in drug delivery efficiency arising from the time delay between actuation of the MDI and inhalation. The new monograph provides guidance on new test conditions, designed to capture the “as inhaled” characteristics of the dose under representative conditions.
The BAC 2000 is a timer-controlled two-way solenoid valve. It provides near instantaneous starting and stopping of the air flow during testing and has both delay and inhaled time functions. The delay feature allows sampling of the aerosol from the spacer or VHC to start a defined time after actuation of the MDI. The BAC 2000 can also be useful for controlling the duration for which nebulizer sampling is conducted and for actuating breath-actuated MDIs during testing. It can be used for both dose uniformity testing and for aerodynamic particle size measurement by cascade impaction, where appropriate.
The BRS 1100 is a simple, microprocessor controlled breathing simulator designed to generate the breathing profiles specified by USP and Ph.Eur. for dose uniformity testing of nebulizers and, in the case of the new draft USP monograph, for MDIs with spacers and VHCs. Neonate, infant, child and adult profiles can all be precisely generated by varying tidal volume, frequency, duration and inhalation/exhalation ratio. Starting the breathing cycle at the point of inhalation or exhalation can also be controlled as required for the testing of MDIs with spacers and VHCs, when comparing fully coordinated and uncoordinated use.
Source: Copley Scientific