Does the United States Pharmacopeia throat introduce de-agglomeration of carrier-free powder from inhalers?

Purpose: We hypothesize that the USP induction port may de-agglomerate carrier-free powder emitting from dry powder inhalers (DPIs).

Methods: Aerosols emitting from a range of DPIs (Spinhaler®, Turbuhaler® and Osmohaler™) and induction ports (USP throat, straight tube, Alberta idealized mouth-throat geometry (AG)) were sized by laser diffraction. Total drug recovery was obtained by HPLC and fine particle fraction computed.

Dissolution kinetic behavior of drug nanoparticles and their conformity to the diffusion model.

Advances in nanomedicine are expected to escalate in the coming years, particularly related to the availability and delivery of optimum dosage. It is crucial that the dissolution behavior of such novel dosage forms be adequately scrutinized to maximize their therapeutic benefits. In this work, the dissolution behavior of irregularly shaped nanoparticles was analyzed using a modified negative-two-thirds-root diffusion model (with shape factor, sigma, incorporated into the equation to describe shape evolution).

What is a suitable dissolution method for drug nanoparticles?

Purpose: Many existing and new drugs fail to be fully utilized because of their limited bioavailability due to poor solubility in aqueous media. Given the emerging importance of using nanoparticles as a promising way to enhance the dissolution rate of these drugs, a method must be developed to adequately reflect the rate-change due to size reduction. At present, there is little published work examining the suitability of different dissolution apparatus for nanoparticles.

Evaluation on the use of confined liquid impinging jets for the synthesis of nanodrug particles.

Most pharmaceutical compounds can benefit from being produced with a small particle size to enhance processing or therapeutic performance. Confined liquid impinging jets (CLIJ) were employed in this study to evaluate the feasibility and limitations in the production of nanodrugs (i.e.

Effect of design on the performance of a dry powder inhaler using computational fluid dynamics. Part 2: Air inlet size.

This study investigates the effect of air inlet size on (i) the flowfield generated in a dry powder inhaler, and (ii) the device-specific resistance, and the subsequent effect on powder deagglomeration. Computational fluid dynamics (CFD) analysis was used to simulate the flowfield generated in an Aerolizer with different air inlet sizes at 30, 45, and 60 l/min. Dispersion performance of the modified inhalers was measured using mannitol powder and a multistage liquid impinger at the same flow rates.

Influence of air flow on the performance of a dry powder inhaler using computational and experimental analyses.

Purpose: The aims of the study are to analyze the influence of air flow on the overall performance of a dry powder inhaler (Aerolizer and to provide an initial quantification of the flow turbulence levels and particle impaction velocities that maximized the inhaler dispersion performance.

Methods: Computational fluid dynamics (CFD) analysis of the flow field in the Aerolizer, in conjunction with experimental dispersions of mannitol powder using a multistage liquid impinger, was used to determine how the inhaler dispersion performance varied as the device flow rate was increased.

Results: Both the powder dispersion and throat deposition were increased with air flow.

The role of capsule on the performance of a dry powder inhaler using computational and experimental analyses.

Purpose: To study the fundamental effects of the spinning capsule on the overall performance of a dry powder inhaler (Aerolizer).

Methods: The capsule motion was visualized using high-speed photography. Computational fluid dynamics (CFD) analysis was performed to determine the flowfield generated in the device with and without the presence of different sized capsules at 60 l min(-1).

How much particle surface corrugation is sufficient to improve aerosol performance of powders?

Purpose: The current study aimed to quantify the different degree of particle surface corrugation and correlate it to the aerosol performance of powders.

Methods: Powders of different degree of surface corrugation were prepared by spray drying under varying conditions. The solid-state properties of the powders including particle size, morphology, crystal form, true density, and moisture content were characterized.

Effect of design on the performance of a dry powder inhaler using computational fluid dynamics. Part 1: Grid structure and mouthpiece length.

This study investigates (1) the effect of modifying the design of a dry powder inhaler on the device performance, and (2) which design features significantly contribute to overall inhaler performance. Computational Fluid Dynamics (CFD) analysis was performed to determine how the flowfield generated in an Aerolizer at 60 l min(-1) varied when the inhaler grid and mouthpiece were modified. The computational models were validated by Laser Doppler Velocimetry (LDV).