Budesonide nanoparticle agglomerates as dry powder aerosols with rapid dissolution

Intact nanoparticulate indomethacin in fast-dissolving carrier particles by combined wet milling and aerosol flow reactor methods

PURPOSE

Drug development is often hindered by a drug's low dissolution rate. We present a method to increase dissolution rate of a drug powder by producing crystalline nanoparticles that are dispersed in carrier microparticles.

METHODS

Indomethacin crystals of a few hundred nanometers are prepared by media milling using poloxamer 188 as a stabilizer. Nanoparticles are embedded into microparticles with a mannitol matrix and an L-leucine coating layer using an aerosol flow reactor method.

RESULTS

Microparticles stabilize the primary nanoparticles in an intact crystalline form and release them when re-dispersed in aqueous medium. Secondary microparticle structure dissolves rapidly, resulting in a fast release and dissolution of indomethacin. In this manner, it is possible to change the surface layer of the particles from the one needed for nanoparticle production to one more suitable for process formulation of pharmaceuticals for, e.g., tablet or pulmonary products.

CONCLUSIONS

Particle assemblies where nano-sized crystalline drug domains are embedded in solid microparticles are presented. The present work is a promising approach towards a "nanos-in-micros" concept as a tool for pharmaceutical nanoparticle processing.

Inhaler devices: what remains to be done?

The 1000 Years of Pharmaceutical Aerosols Conference convened posing the question; "what remains to be done?" When applying this question to the topic of inhaler devices, two hugely different perspectives could be taken. On the one hand, it could be argued that because there is an array of delivery systems available and the industry, prescribing physicians and patients alike have considerable choice, why would we believe it necessary to do anything further? On the other hand, as an industry, we are constantly reminded by our "customers" that the inhaler devices available are less than adequate, and in some cases woefully inadequate, that they are not "patient" friendly, not intuitive to use and importantly do nothing to encourage the patient to take the medication as intended and as prescribed. So, taking the second point of view as more reflective of reality--the Voice of the Customer--our starting point must be that there is still much to do in the field of inhaler devices. The purpose of this article is to outline some key basic requirements for inhaler design and perhaps to question some of the entrenched thinking that has pervaded inhaler product design for too many years.

Randomized phase II trial of inhaled budesonide versus placebo in high-risk individuals with CT screen-detected lung nodules

Screening CT identifies small peripheral lung nodules, some of which may be pre- or early invasive neoplasia. Secondary end point analysis of a previous chemoprevention trial in individuals with bronchial dysplasia showed reduction in size of peripheral nodules by inhaled budesonide. We performed a randomized, double-blind, placebo-controlled phase IIb trial of inhaled budesonide in current and former smokers with CT-detected lung nodules that were persistent for at least 1 year. A total of 202 individuals received inhaled budesonide, 800 μg twice daily or placebo for 1 year. The primary endpoint was the effect of treatment on target nodule size in a per person analysis after 1 year. The per person analysis showed no significant difference between the budesonide and placebo arms (response rate 2% and 1%, respectively). Although the per lesion analysis revealed a significant effect of budesonide on regression of existing target nodules (P = 0.02), the appearance of new lesions was similar in both groups and thus the significance was lost in the analysis of all lesions. The evaluation by nodule type revealed a nonsignificant trend toward regression of nonsolid and partially solid lesions after budesonide treatment. Budesonide was well tolerated, with no unexpected side effects identified. Treatment with inhaled budesonide for 1 year did not significantly affect peripheral lung nodule size. There was a trend toward regression of nonsolid and partially solid nodules after budesonide treatment. Because a subset of these nodules is more likely to represent precursors of adenocarcinoma, additional follow-up is needed.

Iodinated NanoClusters as an inhaled computed tomography contrast agent for lung visualization

Improvements to contrast media formulations may be an effective way to increase the accuracy and effectiveness of thoracic computed tomography (CT) imaging in disease evaluation. To achieve contrast enhancement in the lungs, a relatively large localized concentration of contrast media must be delivered. Inhalation offers a noninvasive alternative to intrapleural injections for local lung delivery, but effective aerosolization may deter successful imaging strategies. Here, NanoCluster technology was applied to N1177, a diatrizoic acid derivative, to formulate low density nanoparticle agglomerates with aerodynamic diameters <or=5 microm. Excipient-free N1177 NanoCluster powders were delivered to rats by insufflation or inhalation and scanned using CT up to 1 h post dose. CT images after inhalation showed a approximately 120 (HU) Hounsfield units contrast increase in the lungs, which was more than sufficient contrast for thoracic CT imaging. Lung tissue histology demonstrated that N1177 NanoClusters did not damage the lungs. NanoCluster particle engineering technology offers a novel approach to safely and efficiently disseminate high concentrations of contrast agents to the lung periphery.

Preparation of budesonide-loaded porous PLGA microparticles and their therapeutic efficacy in a murine asthma model

Inhaling corticosteroids, such as budesonide (BD), is the most common treatment for asthma. However, frequent steroid administration is associated with many side effects. We hypothesized that porous microparticles containing BD could provide an effective treatment method for asthma, as the sustained delivery of corticosteroid and a reduced number of doses could be achieved using porous polymeric microparticles. Porous microparticles were prepared from poly(lactic-co-glycolic acid) (PLGA) by a water-in-oil-in-water double emulsion method with ammonium bicarbonate as the porogen. Varying the porogen concentration controlled the morphology, particle size, and pore size of the PLGA microparticles, with particle size and pore size increasing as the porogen concentration increased. The BD loading efficiency in the porous PLGA microparticles was about 60%, and BD was released from the porous microparticles in a sustained manner for 24h in vitro. Lung uptake efficiency of the porous PLGA microparticles in mice was significantly higher than that of non-porous PLGA microparticles. Budesonide-loaded porous PLGA microparticles were delivered to asthmatic mice, and the numbers of inflammatory cells in bronchoalveolar lavage (BAL) fluid and tissue sections were significantly reduced when the drug was administrated every 3days. We also found significantly reduced bronchial hyperresponsiveness of asthmatic mice after treatment with budesonide-loaded porous PLGA microparticles. This approach to controlling the porous structure of polymeric microparticles, as well as the release behavior of drugs from the microparticles, could have useful applications in the pulmonary delivery of many therapeutic drugs.

Research Spotlight: Therapeutic Particles and Biomaterials Technology Laboratory at The University of Kansas

Novel technologies to enhance therapeutic delivery and biomaterial performance are fundamental to the development of improved products with fewer unwanted side effects. The Therapeutic Particles and Biomaterials Technology Laboratory at The University of Kansas (KS, USA) works at the interface of medicine and engineering to develop novel materials that enhance therapeutic delivery in a variety of biomedical applications. Research areas include aerosol drug delivery, targeted nanoparticles for drug and contrast agent delivery, biomaterials for tissue engineering and polymer therapeutics. The lab works with industry, academia and law firms through a variety of mechanisms such as fee-for-service, contract research and collaboration. Ultimately, the group aims to develop materials and drug delivery platforms that are fundamentally unique yet simple solutions to improve human health.

Dry powdered aerosols of diatrizoic acid nanoparticle agglomerates as a lung contrast agent

Aerosolized contrast agents may improve the resolution of biomedical imaging modalities and enable more accurate diagnosis of lung diseases. Many iodinated compounds, such as diatrizoic acid, have been shown to be safe and useful for radiographic examination of the airways. Formulations of such compounds must be improved in order to allow imaging of the smallest airways. Here, diatrizoic acid nanoparticle agglomerates were created by assembling nanoparticles into inhalable microparticles that may augment deposition in the lung periphery. Nanoparticle agglomerates were fully characterized and safety was determined in vivo. After dry powder insufflation to rats, no acute alveolar tissue damage was observed 2h post-dose. Diatrizoic acid nanoparticle agglomerates possess the characteristics of an efficient and safe inhalable lung contrast agent.