Investigation of the distribution of particles of drugs with the help of cascade impactor

BACKGROUND. Successful nebulization is a result of joint usage of nebulizer and medication, which equally define availability and disposition of the active substance. Amount of the substance delivered by different nebulizer systems may differ in more than 10 times. OBJECTIVE. The aim of the study was to investigate the distribution of aerosol particles of drugs for inhalation manufactured by «Yuria-Pharm» under conditions of usage of Ulaizer Home. MATERIALS AND METHODS. We investigated Ulaizer Home nebulizer and medications for inhalation (Decasan, Lorde hyal, Nebufluson, Nebutamol) with the help of new generation impactor (“Copley Scientific Limited”, Great Britain). RESULTS AND DISCUSSION. Mass median aerodynamic diameter (MMAD) of Decasan particles was 4.878 µm, geometric standard deviation (GSD) – 1.72. MMAD of Lorde hyal particles was 3.194 µm, GSD – 1.556. Drop distribution for Nebutamol was alike the distribution for non-viscous aqueous solutions (MMAD – 5.363 µm, GSD – 1.924). For Nebufluson MMAD was 5.491 µm, GSD – 1.724. CONCLUSIONS. The delivery of the inhaled drug to the required area of the respiratory system is a key to successful nebulization. It directly depends on the parameters of the aerosol. The distribution of particles of drugs manufactured by «Yuria-Pharm» in case of nebulization using Ulaizer Home allows to deliver the required amount of drug to the predefined parts of the respiratory system.

Characterization of Polymeric Micelles for Pulmonary Delivery of Beclomethasone Dipropionate

The potential of using poly-(ethylene oxide)-block-distearoyl phosphatidyl-ethanolamine (mPEG-DSPE) polymer to prepare BDP-loaded micelles with high entrapment efficiency and mass median aerodynamic diameter of less than 5 μm demonstrating sustained release properties was evaluated. The result showed that lyophilized BDP-loaded polymeric micelles with entrapment efficiency of more than 96% could be achieved. Entrapment efficiency was affected by both the drug to polymer molar ratio and the amount of drug used. Investigation using FTIR and DSC confirmed that there was no chemical or physical interaction and the drug was molecularly dispersed within the micelles. TEM images showed that the drug-loaded polymeric micelles were spherical in shape with multivesicular morphology. Further analysis by photon correlation spectroscopy indicated that the particle size of the BDP-loaded micelles was about 22 nm in size. In vitro drug release showed a promising sustained release profile over six days following the Higuchi model. The mass median aerodynamic diameter and fine particle fraction were suitable for pulmonary delivery. Moreover, the small amount of deposited drug in the induction port (throat deposition) suggested possible reduction in incidence of oropharyngeal candidiasis, a side effect normally associated with inhaled corticosteroids therapy. The high encapsulation efficiency, comparable inhalation properties, sustained release behavior together with biocompatibility nature of the polymer support the potential of BDP-loaded polymeric micelles as a versatile delivery system to be used in the treatment of asthma and chronic obstructive pulmonary disease.

Effect of nebulized lidocaine on ventilatory response to CO2 in healthy subjects

Partial vagal blockade produced by inhalation of a local anesthetic aerosol has enhanced CO2 responsiveness in some studies but not in others. The effect of inhaled local anesthetic may depend on the amount of drug depositing in the central airways, i.e., the degree of airway anesthesia. We examined the ventilatory response to CO2 rebreathing in 11 healthy subjects before and after inhalation of 4% lidocaine and a normal saline control solution. Lidocaine and control solutions were aerosolized via two different nebulizers: one produced particles with a mass median aerodynamic diameter of 5.28 microns, and the other produced particles with a mass median aerodynamic diameter of 1.76 microns. The ventilatory response to CO2 was not affected by the control solution. In contrast, the ventilatory response to CO2 was significantly increased after aerosolized lidocaine when administered via the moderate-particle-size nebulizer (2.13 +/- 0.66 vs. 1.83 +/- 0.54 l.min-1.Torr-1 during control, P = 0.01) but not via the small-particle-size nebulizer (1.96 +/- 0.82 vs. 1.94 +/- 0.84 l.min-1.Torr-1 during control, P = NS). The increase in ventilation was achieved predominantly by an increase in frequency (P = 0.01) while tidal volume was unchanged. In conclusion, airway receptors accessible to inhaled local anesthetic play a role in the control of breathing during CO2 rebreathing. Previous negative studies may be due to differences in nebulizer technique, affecting the amount of drug depositing within the central airways.