Modification of Electrostatic Charge on Inhaled Carrier Lactose Particles by Addition of Fine Particles

Abstract

Triboelectrification affects particle adhesion and agglomeration and hence the formulation, manufacture, and use of dry powder inhaler (DPI) devices. Electrostatic charge measurement of two component mixes of spray-dried or crystalline lactose fine particles (< 10 microns) 0, 5, 10, 15, 20, and 30% w/w with spray-dried or crystalline lactose 63-90 microns, respectively, has been undertaken using a system incorporating pneumatic transport of the mixed powders to a stainless steel cyclone charging device. The magnitude of charge on the mixes was shown to decrease with increased fine particle content, and there was no significant difference in charge for each concentration between spray-dried and crystalline lactose. Both the variation of charge and powder adhesion to the cyclone surface increased with increase in fine particle content. The proportion of fine particles in carrier systems in DPIs may thus have an important role where triboelectrification is involved.

Lactose characteristics and the generation of the aerosol

“…The materials of the mixer vessel (stainless steel) and the device constituents (polypropylene and acetal) influence adhesion as well as the magnitude and polarity of the charges acquired by the powders as a function of the nature of the powder [24]. Furthermore, the addition of a fine-lactose excipient ( 10 μm) to coarse lactose decreases the magnitude of triboelectrification during mixing [25]. The increase in amorphous content and the use of a carrier with a wide PSD affects the polarity and the magnitude of the lactose triboelectric charges [26,27].…”

Chargeability measurements of selected pharmaceutical dry powders to assess their electrostatic charge control capabilities

“…23 Watano et al, 21 using an electrostatic field strength sensor, reported that lactose (Pharmatose 200M, DMW, International, Veghel, The Netherlands) exhibited a positive charge during a stainless steel fluidized bed test. Bennett et al 24 tested crystalline and spray-dried lactose samples neutralized with a radioactive source in a stainless steel cyclone, obtaining a negative charge in both cases. Murtomaa et al 22 Note from Figure 4 that the absolute value of the volume specific chargeability (mV/0.5 cc) increased as the particle size decreased from the L90 to the M5 grade.…”

Dry Powder Inhalers: Study of the Parameters Influencing Adhesion and Dispersion of Fluticasone Propionate

“…Interestingly, different mixing sequences were also shown to result in different lung deposition profiles of API (22,23). The addition of fine particles of lactose was also shown to reduce the electrostatic charge of coarse lactose particles (24).…”