Preparation and in vitro aerosol performance of spray-dried Shuang-Huang-Lian corrugated particles in carrier-based dry powder inhalers

Effects of L-leucine on the properties of spray-dried swellable microparticles with wrinkled surfaces for inhalation therapy of pulmonary fibrosis

Swellable microparticles (SMs) provide a potential strategy for achieving sustained inhalation therapy. However, spray dried SMs are highly hygroscopic, exhibiting poor flowability and dispersibility properties. This study aimed at determining whether L-leucine (LL) can improve aerosolization performance of SMs with wrinkled surface and its potential mechanisms. Cryptotanshinone was co-spray dried with chitosan and LL (0-40%, mass fraction in carrier materials), after which the production yield, particle size, density, encapsulation efficiency, morphology, cohesion, crystallinity, surface LL distribution, hygroscopicity, water content and in vitro aerosolization performance of the developed formulations were characterized. In addition, we determined whether LL, as a hydrophobic amino acid, would impair swellability and macrophage phagocytosis of SMs. The possible impact of LL on in vitro drug release, cytotoxicity and anti-fibrosis effects on MRC-5 cells was also investigated. As the LL content increased, LL began to crystallize. At 7.5% LL, water content and hygroscopicity of the SMs were at their lowest. Moreover, at 7.5% LL, surface enrichment increased rapidly after which it achieved a comparatively complete coverage at 20-40% LL. However, LL ≥ 20% caused the formation of over-wrinkled, even dimpled or hollow particles, which significantly deteriorated powder properties. Optimum aerosolization performance was obtained at 10% LL, irrespective of its crystallization behavior, accompanied by the lowest cohesion, optimal flowability and production yield, and without impaired swellability, macrophage uptake and anti-fibrosis efficacy. The optimal formulation did not exhibit optimum surface LL coverage, implying that improvement of aerosolization performance of wrinkled SMs by LL not simply depended on its surface enrichment, but its significant influence on morphology and on related powder properties as well.

The effect of ethanol on the habit and in vitro aerodynamic results of dry powder inhalation formulations containing ciprofloxacin hydrochloride

In the case of dry powder inhalation systems (DPIs), the development of carrier-free formulations has gained increased attention. Thereby, spray-drying is a promising technology and is widely used to produce carrier-free DPIs. Numerous works have been published about the co-spray-drying of active ingredients with various solid excipients and their effect on the physicochemical characteristics and aerodynamic properties of the formulations. However, only a few studies have been reported about the role of the solvents used in the stock solutions of spray-dried formulations. In the present work, DPI microcomposites containing ciprofloxacin hydrochloride were prepared by spray-drying in the presence of different ethanol concentrations. The work expresses the roughness, depth and width of the dimples for particle size as a novel calculation possibility, and as a correlation between the MMAD/D_0.5 ratio and correlating it with cohesion work, these new terms and correlations have not been published – to the best of our knowledge – which has resulted in gap-filling findings. As a result, different proportions of solvent mixtures could be interpreted and placed in a new perspective, in which the influence of different concentrations of ethanol on the habit of the DPI formulations, and thus on in vitro aerodynamic results. Based on these, it became clear why we obtained the best in vitro aerodynamic results for DPI formulation containing 30% ethanol in the stock solution.

Development of Aggregation-Caused Quenching Probe-Loaded Pressurized Metered-Dose Inhalers with Fluorescence Tracking Potentials

Recently, pressurized metered-dose inhalers (pMDIs) are getting more attention as an effective approach of pulmonary drug delivery, and nanoparticle-based formulations have become a new generation of pMDIs, especially for water insoluble drugs. Up until now, there is no clinical application of nanoparticle-based pMDIs. The main hurdle remains in the lack of knowledge of the in vivo fate of those systems. In this study, a fluorescent probe named P4 with aggregation-caused quenching (ACQ) effect was loaded in the nanoparticle-based pMDIs to track the in vivo fate. P4 probe expressed strong fluorescence when distributed in intact nanoparticles, but quenched in the in vivo aqueous environment due to molecular aggregation. Experimentally, P4 probe was encapsulated into solid lipid nanoparticles (SLN) as P4-SLN, and then, the formulation of pMDIs was optimized. The content (w/w) of the optimal formulation (P4-SLN-pMDIs) was as follows: 6.02% Pluronic® L64, 12.03% ethanol, 0.46% P4-SLN, and 81.49% 1,1,1,2-tetrafluoroethane (HFA-134a). P4-SLN-pMDI was transparent in appearance, possessed a particle size of 132.07 ± 3.56 nm, and the fine particle fraction (FPF) was 39.53 ± 1.94%, as well good stability was shown within 10 days. The results indicated P4-SLN-pMDI was successfully prepared. Moreover, the ACQ property of P4-SLN-pMDIs was verified, which ensured the fluorescence property as a credible tool for in vivo fate study. Taken together, this work established a platform that could provide a firm theoretical support for exploration of the in vivo fate of nanoparticle-based pMDIs in subsequent studies. Grapical abstract.

The Effect of Particle Size and Surface Roughness of Spray-Dried Bosentan Microparticles on Aerodynamic Performance for Dry Powder Inhalation

The purpose of this study was to prepare spray dried bosentan microparticles for dry powder inhaler and to characterize its physicochemical and aerodynamic properties. The microparticles were prepared from ethanol/water solutions containing bosentan using spray dryer. Three types of formulations (SD60, SD80, and SD100) depending on the various ethanol concentrations (60%, 80%, and 100%, respectively) were used. Bosentan microparticle formulations were characterized by scanning electron microscopy, powder X-ray diffraction, laser diffraction particle sizing, differential scanning calorimetry, Fourier-transform infrared spectroscopy, dissolution test, and in vitro aerodynamic performance using Andersen cascade impactor^™ (ACI) system. In addition, particle image velocimetry (PIV) system was used for directly confirming the actual movement of the aerosolized particles. Bosentan microparticles resulted in formulations with various shapes, surface morphology, and particle size distributions. SD100 was a smooth surface with spherical morphology, SD80 was a rough surfaced with spherical morphology and SD60 was a rough surfaced with corrugated morphology. SD100, SD80, and SD60 showed significantly high drug release up to 1 h compared with raw bosentan. The aerodynamic size of SD80 and SD60 was 1.27 µm and SD100 was 6.95 µm. The microparticles with smaller particle size and a rough surface aerosolized better (%FPF: 63.07 ± 2.39 and 68.27 ± 8.99 for SD60 and SD80, respectively) than larger particle size and smooth surface microparticle (%FPF: 22.64 ± 11.50 for SD100).

Co-spraying of carriers (mannitol-lactose) as a method to improve aerosolization performance of salbutamol sulfate dry powder inhaler

Although in dry powder inhaler (DPI) formulations a single carrier is used, a single carrier is not able to provide an excellent aerosolization performance when it is used in DPI formulations. Thereby, the aim of this study was to engineer a suitable ternary mixture of mannitol-lactose-leucine to be used in a DPI formulation with enhanced aerosolization performance. To this end, binary mixtures of mannitol:lactose containing a constant amount of leucine (5% w/w of carriers) were spray-dried as a single solution. Spray-dried samples were blended with salbutamol sulfate to determine the efficiency of their aerosolization performance. Interestingly, note that lactose was in its amorphous state stabilized by the presence of mannitol in the samples. Spray-dried mannitol without lactose showed a combination of the α- and β-polymorphic forms which was the case in all other ratios of mannitol:lactose. It was shown that the highest fine particle fraction (FPF) was 62.42 ± 4.21% which was obtained for the distinct binary mixtures (1:3 mannitol:lactose) compared to a single carrier. This study opens a new window to investigate further the implementation of binary mixtures of sugar carriers containing leucine in DPI formulations to overcome poor aerosolization performance the mentioned DPI formulations.

Rifampicin-Carbohydrate Spray-Dried Nanocomposite: A Futuristic Multiparticulate Platform For Pulmonary Delivery

Purpose

Rifampicin, a first-line anti-tuberculosis drug, was loaded into a carbohydrate-based spray-dried nanocomposite with the aim to design a dry powder inhalation formulation. This strategy can enable efficient distribution of rifampicin within the lungs, localizing its action, enhancing its bioavailability and reducing its systemic exposure consequently side effects.

Methods

The respirable nanocomposite was developed utilizing spray drying of rifampicin nanosuspension employing a combination of mannitol, maltodextrin and leucine as microparticles matrix formers. Detailed physicochemical characterization and in-vitro inhalation properties of the nanocomposite particles were investigated. Compatibility studies were carried out using differential scanning calorimetry and Infrared spectroscopy techniques. Moreover, pulmonary in-vitro cytotoxicity on alveolar basal epithelial cells was performed and evaluated.

Results

Nanocomposite-based rifampicin-loaded dry inhalable powder containing maltodextrin, mannitol and leucine at a ratio of 2:1:1 was successfully formulated. Rifampicin loading efficiency into the carbohydrate nanocomposite was in the range of 89.3% to 99.2% w/w with a suitable particle size (3.47-6.80 µm) and unimodal size distribution. Inhalation efficiency of the spray-dried nanosuspension was significantly improved after transforming into an inhalable carbohydrate composite. Specifically, mannitol-based powder had higher respirable fraction (49.91%) relative to the corresponding formulation of maltodextrin. Additionally, IC₅₀ value of rifampicin nanocomposite was statistically significantly higher than that of free drug thus providing superior safety profile on lung tissues.

Conclusion

The obtained results suggested that spray drying of rifampicin nanosuspension utilizing carbohydrates as matrix formers can enhance drug inhalation performance and reduce cellular toxicity. Thus, representing an effective safer pulmonary delivery of anti-tuberculosis drugs.

Dry Powder Inhalers: A Focus on Advancements in Novel Drug Delivery Systems

Administration of drug molecules by inhalation route for treatment of respiratory diseases has the ability to deliver drugs, hormones, nucleic acids, steroids, proteins, and peptides, particularly to the site of action, improving the efficacy of the treatment and consequently lessening adverse effects of the treatment. Numerous inhalation delivery systems have been developed and studied to treat respiratory diseases such as asthma, COPD, and other pulmonary infections. The progress of disciplines such as biomaterials science, nanotechnology, particle engineering, molecular biology, and cell biology permits further improvement of the treatment capability. The present review analyzes modern therapeutic approaches of inhaled drugs with special emphasis on novel drug delivery system for treatment of various respiratory diseases.

Effects of Chung-Pae Inhalation Therapy on a Mouse Model of Chronic Obstructive Pulmonary Disease

Chung-pae (CP) inhalation therapy is a method frequently used in Korea to treat lung disease, especially chronic obstructive pulmonary disease (COPD). This study investigated the effects of CP inhalation on a COPD animal model. C57BL/6 mice received porcine pancreatic elastase (PPE) and lipopolysaccharide (LPS) alternately three times for 3 weeks to induce COPD. Then, CP (5 or 20 mg/kg) was administered every 2 h after the final LPS administration. The effect of CP was evaluated by bronchoalveolar lavage (BAL) fluid analysis, histological analysis of lung tissue, and reverse transcription polymerase chain reaction analysis of mRNA of interleukin- (IL-) 1β, tumor necrosis factor- (TNF-) α, IL-6, and tumor growth factor- (TGF-) β. Intratracheal CP administration reduced the number of leukocytes and neutrophils in BAL fluid, inhibited the histological appearance of lung damage, and decreased the mRNA levels of the proinflammatory cytokines IL-1β, TNF-α, IL-6, and TGF-β. Intratracheal CP administration effectively decreased the chronic inflammation and pathological changes in a PPE- and LPS-induced COPD mouse model. Therefore, we suggest that CP is a promising strategy for COPD.