Development of budesonide microparticles using spray-drying technology for pulmonary administration: design, characterization, in vitro evaluation, and in vivo efficacy study

Preparation and evaluation of βcyclodextrin-based nanosponges loaded with Budesonide for pulmonary delivery

Budesonide (BUD) is a glucocorticosteroid used to treat chronic obstructive pulmonary disease. Despite this, it is a hydrophobic compound with low bioavailability. To address these hurdles, non-toxic and biocompatible βcyclodextrin-based nanosponges (βCD-NS) were attempted. BUD was loaded on five different βCD-NS at four different ratios. NS with 1,1'-carbonyldiimidazole (CDI) as a crosslinking agent, presented a higher encapsulation efficiency ( ̴ 80%) of BUD at 1:3 BUD: βCD-NS ratio (BUD-βCD-NS). The optimized formulations were characterized by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), water absorption capacity (WAC), scanning electron microscopy (SEM), X-ray powder diffraction studies (XRD), particle size, zeta potential, encapsulation efficiency, in vitro and in vivo release studies, acute toxicity study, solid-state characterization, and aerosol performance. In vitro-in vivo correlation and cytotoxicity of the formulations on alveolar cells in vitro were further determined. In vitro and in vivo studies showed almost complete drug release and drug absorption from the lungs in the initial 2 h for pure BUD, which were sustained up to 12 h from BUD loaded into nanosponges (BUD-βCD-NS). Acute toxicity studies and in vitro cytotoxicity studies on alveolar cells proved the safety of BUD-βCD-NS. Several parameters, including particle size, median mass aerodynamic diameter, % fine particle fraction, and % emitted dose, were evaluated for aerosol performance, suggesting the capability of BUD-βCD-NS to formulate as a dry powder inhaler (DPI) with a suitable diluent. To sum up, this research will offer new insights into the future advancement of βCD-NS as drug delivery systems for providing controlled release of therapeutic agents against pulmonary disease.

In vitro-in vivo correlation of cascade impactor data for orally inhaled pharmaceutical aerosols

In vitro-in vivo correlation is the establishment of a predictive relationship between in vitro and in vivo data. In the context of cascade impactor results of orally inhaled pharmaceutical aerosols, this involves the linking of parameters such as the emitted dose, fine particle dose, fine particle fraction, and mass median aerodynamic diameter to in vivo lung deposition from scintigraphy data. If the dissolution and absorption processes after deposition are adequately understood, the correlation may be extended to the pharmacokinetics and pharmacodynamics of the delivered drugs. Correlation of impactor data to lung deposition is a relatively new research area that has been gaining recent interest. Although few in number, experiments and meta-analyses have been conducted to examine such correlations. An artificial neural network approach has also been employed to analyse the complex relationships between multiple factors and responses. However, much research is needed to generate more data to obtain robust correlations. These predictive models will be useful in improving the efficiency in product development by reducing the need of expensive and lengthy clinical trials.

Rational design of multistage drug delivery vehicles for pulmonary RNA interference therapy

Small interfering RNA (siRNA) therapy has significant potential for the treatment of myriad diseases, including cancer. While intravenous routes of delivery have been found to be effective for efficient targeting to the liver, achieving high accumulations selectively in other organs, including lung tissues, can be a challenge. We demonstrate the rational design and engineering of a layer-by-layer (LbL) nanoparticle-containing aerosol that is able to achieve efficient, multistage delivery of siRNA in vitro. For the purpose, LbL nanoparticles were, for the first time, encapsulated in composite porous micro scale particles using a supercritical CO2-assisted spray drying (SASD) apparatus using chitosan as an excipient. Such particles exhibited aerodynamic properties highly favorable for pulmonary administration, and effective silencing of mutant KRAS in lung cancer cells derived from tumors of a non-small cell lung cancer (NSCLC) autochthonous model. Furthermore, efficient alveolar accumulation following inhalation in healthy mice was also observed, corroborating in vitro aerodynamic results, and opening new perspectives for further studies of effective lung therapies These results show that multistage aerosols assembled by supercritical CO₂-assisted spray drying can enable efficient RNA interference therapy of pulmonary diseases including lung cancer.

Pulmonary route of administration is instrumental in developing therapeutic interventions against respiratory diseases

Pulmonary route of drug delivery has drawn significant attention due to the limitations associated with conventional routes and available treatment options. Drugs administered through pulmonary route has been an important research area that focuses on to developing effective therapeutic interventions for asthma, chronic obstructive pulmonary disease, tuberculosis, lung cancer etc. The intravenous route has been a natural route of delivery of proteins and peptides but associated with several issues including high cost, needle-phobia, pain, sterility issues etc. These issues might be addressed by the pulmonary administration of macromolecules to achieving an effective delivery and efficacious therapeutic impact. Efforts have been made to develop novel drug delivery systems (NDDS) such as nanoparticles, microparticles, liposomes and their engineered versions, polymerosomes, micelles etc to achieving targeted and sustained delivery of drug(s) through pulmonary route. Further, novel approaches such as polymer-drug conjugates, mucoadhesive particles and mucus penetrating particles have attracted significant attention due to their unique features for an effective delivery of drugs. Also, use of semi flourinated alkanes is in use for improvising the pulmonary delivery of lipophilic drugs. Present review focuses on to unravel the mechanism of pulmonary absorption of drugs for major pulmonary diseases. It summarizes the development of interventional approaches using various particulate and vesicular drug delivery systems. In essence, the orchestrated attempt presents an inflammatory narrative on the advancements in the field of pulmonary drug delivery.

Co-electrospraying technology as a novel approach for dry powder inhalation formulation of montelukast and budesonide for pulmonary co-delivery

In the current study electrospraying methodology was used for particle engineering of montelukast and budesonide to prepare a combined inhalable dry powder formulation applicable as a smart regimen in asthma treatment. For this, electrospraying was carried out using different solvents and drug concentrations. No carrier was added for the formulation of montelukast-budesonide combination as montelukast played the role of both active ingredient and carrier. Scanning electron microscopy, particle size analysis, gas chromatography, powder X-ray diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry were used to evaluate the physicochemical properties of the produced drug particles. In vitro drug deposition pattern was assessed using next generation impactor, and the dissolution profile of the selected formulations was characterized via modified diffusion franz cell method. The FPF value for the co-electrosprayed carrier free formulation of montelukast-budesonide was 38% with a significantly enhanced dissolution rate for budesonide compared to the budesonide alone formulations. The pharmacological effects of hypothesized combined formulation was assessed by measuring its power to inhibit the production of reactive oxygen species in human normal lung cells. The results showed that the combination of montelukast and budesonide can exert a synergistic effect. The findings in the current study emphasize that using montelukast as a carrier for budesonide not only has greatly improved the aerosolization behavior and dissolution rate of budesonide but also has resulted in synergistic pharmacological effects, indicating the suitability of this combination as an anti-asthmatic therapeutic.

Engineering Tumor-Targeting Nanoparticles as Vehicles for Precision Nanomedicine

As a nascent and emerging field that holds great potential for precision oncology, nanotechnology has been envisioned to improve drug delivery and imaging capabilities through precise and efficient tumor targeting, safely sparing healthy normal tissue. In the clinic, nanoparticle formulations such as the first-generation Abraxane® in breast cancer, Doxil® for sarcoma, and Onivyde® for metastatic pancreatic cancer, have shown advancement in drug delivery while improving safety profiles. However, effective accumulation of nanoparticles at the tumor site is sub-optimal due to biological barriers that must be overcome. Nanoparticle delivery and retention can be altered through systematic design considerations in order to enhance passive accumulation or active targeting to the tumor site. In tumor niches where passive targeting is possible, modifications in the size and charge of nanoparticles play a role in their tissue accumulation. For niches in which active targeting is required, precision oncology research has identified targetable biomarkers, with which nanoparticle design can be altered through bioconjugation using antibodies, peptides, or small molecule agonists and antagonists. This review is structured to provide a better understanding of nanoparticle engineering design principles with emphasis on overcoming tumor-specific biological barriers.

Preparation and Characterization of a Dry Powder Inhaler Composed of PLGA Large Porous Particles Encapsulating Gentamicin Sulfate

Purpose: Direct delivery of aminoglycosides to the lungs was under extensive evaluations during the last decades. Because of large particle size, low density and porous structure, large porous particles (LPPs) are versatile carriers for this purpose. In this study, poly (lactic-co-glycolic acid) (PLGA) LPPs encapsulating gentamicin sulfate were prepared and in vitro characteristics of their freeze-dried powder as a dry powder inhaler (DPI) were evaluated.

Methods: To prepare PLGA LPPs, a double emulsification-solvent evaporation method was optimized and gentamicin sulfate was post-loaded in the LPPs. in vitro characteristics including morphological features, thermal behavior, aerodynamic profile and cumulative drug release were evaluated by the scanning electron microscope (SEM), differential scanning calorimetry (DSC), next-generation cascade impactor (NGI) and Franz diffusion cell respectively.

Results: The obtained results revealed that the preparation method was capable to produce spherical large homogenous highly porous particles. 94% of gentamicin sulfate released from LPPs up to 30 minutes. Mass median aerodynamic diameter (MMAD) and fine particle fraction (FPF) were 4.9 µm and 39% respectively.

Conclusion: In this study, dry powder formulation composed of PLGA LPPs encapsulating gentamicin sulfate showed a promising in vitro behavior as a pulmonary delivery carrier. Improvements on the aerodynamic behavior and in vivo evaluations recommended for further developments.

Mesoporous silica microparticles gated with a bulky azo derivative for the controlled release of dyes/drugs in colon

Mesoporous silica microparticles were prepared, loaded with the dye safranin O (M-Saf) or with the drug budesonide (M-Bud) and capped by the grafting of a bulky azo derivative. Cargo release from M-Saf at different pH values (mimicking those found in the gastrointestinal tract) in the absence or presence of sodium dithionite (a reducing agent mimicking azoreductase enzyme present in the colon) was tested. Negligible safranin O release was observed at pH 6.8 and 4.5, whereas a moderate delivery at pH 1.2 was noted and attributed to the hydrolysis of the urea bond that linked the azo derivative onto the external surface of the inorganic scaffold. Moreover, a marked release was observed when sodium dithionite was present and was ascribed to the rupture of the azo bond in the molecular gate. Budesonide release from M-Bud in the presence of sodium dithionite was also assessed by ultraviolet-visible spectroscopy and high performance liquid chromatography measurements. In addition, preliminary in vivo experiments with M-Saf carried out in mice indicated that the chemical integrity of the microparticles remained unaltered in the stomach and the small intestine, and safranin O seemed to be released in the colon.

Sustained therapeutic efficacy of budesonide-loaded chitosan swellable microparticles after lung delivery: Influence of in vitro release, treatment interval and dose

Sustained drug delivery to the respiratory tract is highly desirable for local treatment of chronic lung diseases. In this context, a correlation of in vitro drug release with in vivo efficacy data is essential to accelerate the application of sustained drug delivery system for inhalation into the clinical setting. In this study, budesonide was incorporated into distinct chitosan-based swellable microparticles, which were characterized, and the in vitro drug release behavior determined. The particles were then given to an allergic asthma animal model as single and successive administrations, and the therapeutic response was determined by measuring cell counts, IL-4 and IL-5 levels in bronchoalveolar lavage fluid, IL-4 and IL-5 mRNA in the lung and by histopathologic examination of lung tissues. After a single administration, the time-dependent therapeutic effect of the swellable microparticles was correlated with the in vitro release behavior, which lasted for 12 or 18 h depending on the molecular weight of the chitosan. After seven days of successive treatment, the number of eosinophils decreased further and IL-4 and IL-5 mRNA expression in the lung tissue was more greatly inhibited. Moreover, the chitosan-based swellable microparticles allowed longer administration intervals (every two days), which decreased the required dose for effectiveness by 50%. These results demonstrate that chitosan-based swellable microparticles can sustain the therapeutic effect of budesonide in the respiratory tract which in principal can be applied to other drugs for the treatment of local lung diseases.

Inhalable Levofloxacin Liposomes Complemented with Lysozyme for Treatment of Pulmonary Infection in Rats: Effective Antimicrobial and Antibiofilm Strategy

Treatment of bacterial infections becomes increasingly complicated due to increasing bacterial resistance and difficulty in developing new antimicrobial agents. Emphasis should be laid on improvising the existing treatment modalities. We studied the improved antimicrobial and antibiofilm activity of levofloxacin (LFX) and lysozyme (LYS) in microbiological studies. LFX at sub-minimum inhibitory concentration with LYS eradicated > 85% of preformed biofilm. LFX was actively loaded into the liposomes using pH gradient method and was spray-dried with LYS solution. Percent entrapment of LFX in liposome was > 80% and prolonged cumulative release of 85% LFX at the end of 12 h. In vitro lung deposition study and solid-state characterization for spray dried LFX liposome in combination with LYS (LFX liposome-LYS) was performed. Co-spray dried product had mass median aerodynamic diameter ranging < 5 μm. In pharmacodynamic study, Staphylococcus aureus infected rats were treated with LFX liposome-LYS. Lungs, bronchoalveolar lavage fluid (BALF), and nasal fluid were evaluated for microbial burden. Expression of cytokine levels in BALF and serum were also studied by ELISA. In addition, mRNA expression for lung inflammatory mediators and lung myeloperoxidase activity were carried out. Further, lungs and histological changes were observed grossly. Untreated infected rat lungs demonstrated higher mRNA expression for inflammatory markers, cytokine levels, and microbial load compared to vehicle control. Conversely, LFX liposome-LYS significantly abated these adverse repercussions. Histology findings were also in agreement of above. Acute toxicity study revealed safeness of LFX liposome-LYS. Our findings confirm LFX liposome-LYS exhibited prolonged, improved antibiofilm and antimicrobial efficacy in treating S. aureus infection.

New perspectives in nanotherapeutics for chronic respiratory diseases

According to the World Health Organization (WHO), hundreds of millions of people of all ages and in all countries suffer from chronic respiratory diseases, with particular negative consequences such as poor health-related quality of life, impaired work productivity, and limitations in the activities of daily living. Chronic obstructive pulmonary disease, asthma, occupational lung diseases (such as silicosis), cystic fibrosis, and pulmonary arterial hypertension are the most common of these diseases, and none of them are curable with current therapies. The advent of nanotechnology holds great therapeutic promise for respiratory conditions, because non-viral vectors are able to overcome the mucus and lung remodeling barriers, increasing pharmacologic and therapeutic potency. It has been demonstrated that the extent of pulmonary nanoparticle uptake depends not only on the physical and chemical features of nanoparticles themselves, but also on the health status of the organism; thus, the huge diversity in nanotechnology could revolutionize medicine, but safety assessment is a challenging task. Within this context, the present review discusses some of the major new perspectives in nanotherapeutics for lung disease and highlights some of the most recent studies in the field.

Nano-Therapeutics for the Lung: State-of-the-Art and Future Perspectives

Inhalation of aerosolized compounds is a popular, non-invasive route for the targeted delivery of therapeutic molecules to the lung. Various types of nanoparticles have been used as carriers to facilitate drug uptake and intracellular action in order to treat lung diseases and/or to facilitate lung repair and growth. These include polymeric nanoparticles, liposomes, and dendrimers, among many others. In addition, nanoparticles are sometimes used in combination with small molecules, cytokines, growth factors, and/or pluripotent stem cells. Here we review the rationale and state-of-the-art nanotechnology for pulmonary drug delivery, with particular attention to new technological developments and approaches as well as the challenges associated with them, the emerging advances, and opportunities for future development in this field.

Recent advances in chitosan-based nanoparticulate pulmonary drug delivery

The advent of biodegradable polymer-encapsulated drug nanoparticles has made the pulmonary route of administration an exciting area of drug delivery research. Chitosan, a natural biodegradable and biocompatible polysaccharide has received enormous attention as a carrier for drug delivery. Recently, nanoparticles of chitosan (CS) and its synthetic derivatives have been investigated for the encapsulation and delivery of many drugs with improved targeting and controlled release. Herein, recent advances in the preparation and use of micro-/nanoparticles of chitosan and its derivatives for pulmonary delivery of various therapeutic agents (drugs, genes, vaccines) are reviewed. Although chitosan has wide applications in terms of formulations and routes of drug delivery, this review is focused on pulmonary delivery of drug-encapsulated nanoparticles of chitosan and its derivatives. In addition, the controversial toxicological effects of chitosan nanoparticles for lung delivery will also be discussed.

Inhalable, large porous PLGA microparticles loaded with paclitaxel: preparation, in vitro and in vivo characterization

Large porous particles (LPPs) could be used as a useful carrier for non-invasive delivery to the deep lung. Pulmonary delivery of paclitaxel-loaded LPPs (PTX-LPPs) can help to eliminate the highly complicated and harmful solvent used in PTX parenteral formulations. PTX-LPPs with mass median aerodynamic diameter (MMAD) of 5.74 ± 0.09 μm, high encapsulation efficiency and good aerosolisation properties were produced using ammonium bicarbonate as porogen. Cytotoxicity of PTX-LPPs on A549 and Calu-6 cell lines was comparable with Free-PTX. Endotracheal administration of PTX-LPPs in rats exhibited PTX plasma concentration in the therapeutic range which lasted 4-fold longer than i.v. injection. The bioavailability was measured as 51 ± 7.1%. The lung targeting efficiency (Te) of PTX-LPPs was 11.9-fold higher than i.v. administration. PTX-LPPs could deliver a higher PTX to lung with a non-toxic plasma level in a longer duration which shows their pulmonary delivery suitability.

Revealing facts behind spray dried solid dispersion technology used for solubility enhancement

Poor solubility and bioavailability of an existing or newly synthesized drug always pose challenge in the development of efficient pharmaceutical formulation. Numerous technologies can be used to improve the solubility and among them amorphous solid dispersion based spray drying technology can be successfully useful for development of product from lab scale to commercial scale with a wide range of powder characteristics. Current review deals with the importance of spray drying technology in drug delivery, basically for solubility and bioavailability enhancement. Role of additives, selection of polymer, effect of process and formulation parameters, scale up optimization, and IVIVC have been covered to gain the interest of readers about the technology. Design of experiment (DoE) to optimize the spray drying process has been covered in the review. A lot more research work is required to evaluate spray drying as a technology for screening the right polymer for solid dispersion, especially to overcome the issue related to drug re-crystallization and to achieve a stable product both in vitro and in vivo. Based on the recent FDA recommendation, the need of the hour is also to adopt Quality by Design approach in the manufacturing process to carefully optimize the spray drying technology for its smooth transfer from lab scale to commercial scale.

Evaluation of Spray BIO-Max DIM-P in Dogs for Oral Bioavailability and in Nu/nu Mice Bearing Orthotopic/Metastatic Lung Tumor Models for Anticancer Activity

PURPOSE

In an effort to prepare an oral dosage form for poorly bioavailable anti-cancer agents, we have incorporated spray drying using a customized spray gun generating enteric coated Self-emulsifying drug delivery systems. The objective of this study was to design and evaluate pharmacokinetics and pharmacodynamic characteristics of Spray BIO-Max DIM-P (SB DIM-P).

METHODS

SB DIM-P was prepared and optimized based on physico-chemical characteristics using design of experiment (DOE-Vr 8.0) software. Pharmacokinetic parameters in dogs and rats were evaluated and analyzed using Winonlin. Anti-tumor activity was carried out in orthotopic and metastatic lung tumor models using size M capsules in mice.

RESULTS

Based on the optimization using DOE analysis of SB DIM-P characteristics, formulations were selected for further investigation. Pharmacokinetic studies showed a 30% increase in oral bioavailability in rats and ~2.9 times more bioavailability of SB DIM-P compare to solution in dogs. SB DIM-P showed ~20-25% more tumor volume/weight reduction in H1650 metastatic tumor model and ~25-30% tumor volume/weight reduction in A549 orthotopic tumor model compared to DIM-P solution.

CONCLUSIONS

Our studies demonstrate the potential application of spray dried enteric coated self-emulsifying delivery system (SB DIM-P) to enhances oral absorption and efficacy of DIM-P in lung tumor models.

Technological and practical challenges of dry powder inhalers and formulations

In the 50 years following the introduction of the first dry powder inhaler to the market, several developments have occurred. Multiple-unit dose and multi-dose devices have been introduced, but first generation capsule inhalers are still widely used for new formulations. Many new particle engineering techniques have been developed and considerable effort has been put in understanding the mechanisms that control particle interaction and powder dispersion during inhalation. Yet, several misconceptions about optimal inhaler performance manage to survive in modern literature. It is, for example still widely believed that a flow rate independent fine particle fraction contributes to an inhalation performance independent therapy, that dry powder inhalers perform best at 4 kPa (or 60 L/min) and that a high resistance device cannot be operated correctly by patients with reduced lung function. Nevertheless, there seems to be a great future for dry powder inhalation. Many new areas of interest for dry powder inhalation are explored and with the assistance of new techniques like computational fluid dynamics and emerging particle engineering technologies, this is likely to result in a new generation of inhaler devices and formulations, that will enable the introduction of new therapies based on inhaled medicines.

Development of Budesonide Loaded Biopolymer Based Dry Powder Inhaler: Optimization, In Vitro Deposition, and Cytotoxicity Study

The progress in the development of DPI technology has boosted the use of sensitive drug molecules for lung diseases. However, delivery of these molecules from conventional DPI to the active site still poses a challenge with respect to deposition efficiency in the lung. At same time, serious systemic side effects of drugs have become a cause for concern. The developed budesonide loaded biopolymer based controlled release DPI had shown maximum in vitro lung deposition with least toxicity. The subject of present study, lactose-free budesonide loaded biopolymer based DPI, further corroborates the great potential of antiasthmatic drugs. This technology is expected to revolutionize the approaches towards enhanced therapeutic delivery of prospective drugs.

Bioavailability enhancement of verapamil HCl via intranasal chitosan microspheres

Chitosan microspheres are potential drug carriers for maximizing nasal residence time, circumventing rapid mucociliary clearance and enhancing nasal absorption. The aim of the present study was to develop and characterize chitosan mucoadhesive microspheres of verapamil hydrochloride (VRP) for intranasal delivery as an alternative to oral VRP which suffers low bioavailability (20%) due to extensive first pass effect. The microspheres were produced using a spray-drying and precipitation techniques and characterized for morphology (scanning electron microscopy), particle size (laser diffraction method), drug entrapment efficiency, thermal behavior (differential scanning calorimetry) and crystallinity (X-ray diffractometric studies) as well as in vitro drug release. Bioavailability of nasal VRP microspheres was studied in rabbits and the results were compared to those obtained after nasal, oral and intravenous administration of VRP solution. Results demonstrated that the microspheres were spherical with size 21-53 μm suitable for nasal deposition. The spray-drying technique was superior over precipitation technique in providing higher VRP entrapment efficiency and smaller burst release followed by a more sustained one over 6h. The bioavailability study demonstrated that the nasal microspheres exhibited a significantly higher bioavailability (58.6%) than nasal solution of VRP (47.8%) and oral VRP solution (13%). In conclusion, the chitosan-based nasal VRP microspheres are promising for enhancing VRP bioavailability by increasing the nasal residence time and avoiding the first-pass metabolism of the drug substance.

Evaluation of Albizia procera gum as compression coating material for colonic delivery of budesonide

The purpose of this research was to develop and evaluate Albizia procera gum as compression-coating polymer for colonic delivery of budesonide. Tablets were prepared by direct compression method using spray-dried lactose and microcrystalline cellulose as filler binders. The compatibility between the drug and the polymer was studied through TGA and FTIR spectroscopy. In vitro drug release were studied in dissolution media with or without 2% rat cecal contents while in vivo X-ray study was conducted on rabbits. The results indicate that procera gum and the drug were compatible with each other and tablet coated with procera gum was suitable for colonic delivery of drugs.

Poly-lactide-co-glycolide nanoparticles containing voriconazole for pulmonary delivery: in vitro and in vivo study

Poly-lactide-co-glycolide nanoparticles (207-605 nm) containing voriconazole (VNPs) were developed using a multiple-emulsification technique and were also made porous during preparation in presence of an effervescent mixture for improved pulmonary delivery. Pulmonary deposition of the particles was studied using a customized inhalation chamber. VNPs had a maximum of 30% (w/w) drug loading and a zeta potential (ZP) value around -20 mV. In the initial 2 hours, 20% of the drug was released from VNPs, followed by sustained release for 15 days. Porous particles had a lower mass median aerodynamic diameter (MMAD) than nonporous particles. Porous particles produced the highest initial drug deposition (~120 μg/g of tissue). The drug was detectable in lungs until 7 days and 5 days after administration, for porous and nonporous particles, respectively. VNPs with improved drug loading were successfully delivered to murine lungs. Porous nanoparticles with lower MMADs showed better pulmonary deposition and sustained presence in lungs.

FROM THE CLINICAL EDITOR

In this paper, voriconazole-containing porous nanoparticles were studied for inhalational delivery to lung infections in a murine model, demonstrating prolonged half-life and improved pulmonary deposition.

Therapeutic liposomal dry powder inhalation aerosols for targeted lung delivery

Therapeutic liposomal powders (i.e., lipospheres and proliposomes) for dry powder inhalation aerosol delivery, formulated with phospholipids similar to endogenous lung surfactant, offer unique opportunities in pulmonary nanomedicine while offering controlled release and enhanced stability. Many pulmonary diseases such as lung cancer, tuberculosis (TB), cystic fibrosis (CF), bacterial and fungal lung infections, asthma, and chronic obstructive pulmonary disease (COPD) could greatly benefit from this type of pulmonary nanomedicine approach that can be delivered in a targeted manner by dry powder inhalers (DPIs). These delivery systems may require smaller doses for efficacy, exhibit reduced toxicity, fewer side effects, controlled drug release over a prolonged time period, and increased formulation stability as inhaled powders. This state-of-the-art review presents these novel aspects in depth.

Chitosan-Grafted Copolymers and Chitosan-Ligand Conjugates as Matrices for Pulmonary Drug Delivery

Recently, much attention has been given to pulmonary drug delivery by means of nanosized systems to treat both local and systemic diseases. Among the different materials used for the production of nanocarriers, chitosan enjoys high popularity due to its inherent characteristics such as biocompatibility, biodegradability, and mucoadhesion, among others. Through the modification of chitosan chemical structure, either by the addition of new chemical groups or by the functionalization with ligands, it is possible to obtain derivatives with advantageous and specific characteristics for pulmonary administration. In this paper, we discuss the advantages of using chitosan for nanotechnology-based pulmonary delivery of drugs and summarize the most recent and promising modifications performed to the chitosan molecule in order to improve its characteristics.

Analysis of process parameters affecting spray-dried oily core nanocapsules using factorial design

The purpose of this work was to optimize the process parameters required for the production of spray-dried oily core nanocapsules (NCs) with targeted size and drug yield using a two-level four-factor fractional factorial experimental design (FFED). The coded process parameters chosen were inlet temperature (X(1)), feed flow rate (X(2)), atomizing air flow (X(3)), and aspiration rate (X(4)). The produced NCs were characterized for size, yield, morphology, and powder flowability by dynamic light scattering, electron microscope, Carr's index, and Hausner ratio measurement, respectively. The mean size of produced NCs ranged from 129.5 to 444.8 nm, with yield varying from 14.1% to 31.1%. The statistical analysis indicated an adequate model fit in predicting the effect of process parameters affecting yield. Predicted condition for maximum yield was: inlet temperature 140°C, atomizing air flow 600 L/h, feed flow rate 0.18 L/h, and aspiration air flow set at 100%, which led to a yield of 30.8%. The morphological analysis showed the existence of oily core and spherical nanostructure. The results from powder flowability analysis indicated average Carr's index and Hausner ratio of 42.77% and 1.76, respectively. Spray-dried oily core NCs with size lower than 200 nm were successfully produced, and the FFED proved to be an effective approach in predicting the production of spray-dried NCs of targeted yield.

Development and evaluation of inhalational liposomal system of budesonide for better management of asthma

Budesonide is a corticosteroid used by inhalation in the prophylactic management of asthma. However, frequent dosing and adverse effects (local and systemic) remain a major concern in the use of budesonide. Liposomal systems for sustained pulmonary drug delivery have been particularly attractive because of their compatibility with lung surfactant components. In the present investigation, pulmonary liposomal delivery system of budesonide was prepared by film hydration method and evaluated for sustained release. Various parameters were optimized with respect to entrapment efficiency as well as particle size of budesonide liposomes. For better shelf life of budesonide liposomes, they were freeze dried using trehalose as cryoprotectant. The liposomes were characterized for entrapment efficiency, particle size, and surface topography; in vitro drug release was evaluated out in simulated lung fluid at 37° at pH 7.4. The respirable or fine particle fraction was determined by using twin stage impinger. The stability study of freeze dried as well as aqueous liposomal systems was carried out at 2-8° and at ambient temperature (28±40). The freeze dried liposomes showed better fine particle fraction and drug content over the period of six months at ambient as well as at 2-8° storage condition compared to aqueous dispersion of liposomes.