Evaluating the effect of sodium alginate and sodium carboxymethylcellulose on pulmonary delivery of levofloxacin spray-dried microparticles

BACKGROUND

Patients with cystic fibrosis commonly suffer from lung infections caused by Pseudomonas aeruginosa. Recently, the Levofloxacin (LVF) nebulizing solution (Quinsair®) has been prescribed for the antimicrobial management. The sustained-release (SR) dry powder formulation of LVF is a convenient alternative to Quinsair®. It has the potential to enhance patient convenience and decrease the likelihood of drug resistance over time.

OBJECTIVE

In this paper, we set forth to formulate and evaluate the potential application of sodium alginate (SA) and sodium carboxymethylcellulose (SCMC) for sustained pulmonary delivery of LVF.

METHODS

The spray-dried (SD) LVF microparticles were formulated using SCMC and SA along with L-leucine (Leu). The microparticles were analyzed in terms of particle size, morphology, x-ray diffraction (XRD), in-vitro drug release, and aerodynamic properties. Selected formulations were further proceeded to short-term stability test.

RESULTS

The polymer-containing samples displayed process yield of 33.31%-39.67%, mean entrapment efficiency of 89% and volume size within the range of 2-5 μm. All the hydrogel microparticles were amorphous and exhibited rounded morphology with surface indentations. Formulations with a drug-to-excipient ratio of 50:50 and higher, showed a 24-h SR. The aerodynamic parameters were fine particle fraction and emitted dose percentage ranging between 46.21%-60.6% and 66.67%-87.75%, respectively. The short-term stability test revealed that the formulation with a 50:50 drug-to-excipient ratio, containing SA, demonstrated better physical stability.

CONCLUSION

The selected formulation containing SA has the potential to extend the release duration. However, further enhancements are required to optimize its performance.

Hyaluronate loaded advanced wound dressing in form of in situ forming hydrogel powders: Formulation, characterization, and therapeutic potential

In this paper, a blend composed of alginate-pectin-chitosan loaded with sodium hyaluronate in the form of an in situ forming dressing was successfully developed for wound repair applications. This complex polymeric blend has been efficiently used to encapsulate hyaluronate, forming an adhesive, flexible, and non-occlusive hydrogel able to uptake to 15 times its weight in wound fluid, and being removed without trauma from the wound site. Calorimetric and FT-IR studies confirmed chemical interactions between hyaluronate and polysaccharides blend, primarily related to the formation of a polyelectrolytic complex between hyaluronate and chitosan. In vivo wound healing assays on murine models highlighted the ability of the loaded hydrogels to significantly accelerate wound healing compared to a hyaluronic-loaded ointment. This was evident through complete wound closure in <10 days, accompanied by fully restored epidermal functionality and no indications of the site of excision or treatment. Therefore, all these results suggest that hyaluronate-loaded powders could be a very promising conformable dressing in several wound healing applications where exudate is present.

Optimization of Spray Drying Process Parameters for the Preparation of Inhalable Mannitol-Based Microparticles Using a Box-Behnken Experimental Design

Inhalation is used for local therapy of the lungs and as an alternative route for systemic drug delivery. Modern powder inhalation systems try to target the required site of action/absorption in the respiratory tract. Large porous particles (LPPs) with a size >5 μm and a low mass density (usually measured as bulk or tapped) of <0.4 g/cm³ can avoid protective lung mechanisms. Their suitable aerodynamic properties make them perspective formulations for deep lung deposition. This experiment studied the effect of spray-drying process parameters on LPP properties. An experimental design of twelve experiments with a central point was realized using the Box-Behnken method. Three process parameters (drying temperature, pump speed, and air speed) were combined on three levels. Particles were formed from a D-mannitol solution, representing a perspective material for lung microparticles. The microparticles were characterized in terms of physical size (laser diffraction), aerodynamic diameter (aerodynamic particle sizer), morphology (SEM), and densities. The novelty and main goal of this research were to describe how the complex parameters of the spray-drying process affect the properties of mannitol LPPs. New findings can provide valuable data to other researchers, leading to the easy tuning of the properties of spray-dried particles by changing the process setup.

The pulmonary route as a way to drug repositioning in COVID-19 therapy

Introduction

The outbreak of the disease caused by the new coronavirus (COVID-19) has been affecting society's routine and its patterns of interaction worldwide, in addition to the impact on the global economy. To date, there is still no clinically effective treatment for this comorbidity, and drug repositioning might be a good strategy considering the established clinical safety profile. In this context, since COVID-19 affects the respiratory tract, a promising approach would be the pulmonary drug delivery.

Objective

Identify repurposing drug candidates for the treatment of COVID-19 based on the data of ongoing clinical trials and in silico studies and also assess their potential to be applied in formulations for pulmonary administration.

Method

A integrative literature review was conducted between June and July 2020, by extracting the results from Clinical Trials, PubMed, Web of Science and Science Direct databases.

Results

By crossing the results obtained from diverse sources, 21 common drugs were found, from which only 4 drugs presented studies of pulmonary release formulations, demonstrating the need for greater investment and incentive in this field.

Conclusion

Even though the lung is a target that facilitates viral infection and replication, formulations for pulmonary delivery of suitable drugs are still lacking for COVID-19 treatment. However, it is indisputable that the pandemic constitutes a concrete demand, with a profound impact on public health, and that, with the appropriate investments, it will give the pharmaceutical industry an opportunity to reinforce the pulmonary delivery field.

Fabrication of doxycycline-loaded electrospun PCL/PEO membranes for a potential drug delivery system

Potential usage of biodegradable and biocompatible polymeric nanofibers is the most attention grabbing topic for the drug delivery system. In order to fabricate ultrafine fibers, electrospinning, one of the well-known techniques, has been extensively studied in the literature. In the present study, the objective is to achieve the optimum blend of hydrophobic and hydrophilic polymers to be used as a drug delivery vehicle and also to obtain the optimum amount of doxycycline (DOXH) to reach the optimum release. In this case, the biodegradable and biocompatible synthetic polymers, poly(ε-caprolactone) (PCL) and poly(ethylene oxide) (PEO), were blended with different ratios for the production of DOXH-loaded electrospun PCL/PEO membranes using electrospinning technique, which is a novel attempt. The fabricated membranes were subsequently characterized to optimize the blending ratio of polymers by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD) and water contact angle analysis. After the characterization studies, different amounts of DOXH were loaded to the optimized blend of PCL and PEO to investigate the release of DOXH from the membrane used as a drug delivery vehicle. In vitro drug release studies were performed, and in vitro drug release kinetics were assessed to confirm the usage of these nanofiber materials as efficient drug delivery vehicles. The results indicated that 3.5% DOXH-loaded (75:25 w/w) PCL/PEO is the most acceptable membrane to provide prolonged release rather than immediate release of DOXH.

Spray-dried fucoidan microparticles for pulmonary delivery of antitubercular drugs

Pulmonary tuberculosis accounts for 80% of cases and the delivery of antitubercular drugs into the lungs allows targeting the infected organ and, possibly, reducing systemic drug toxicity. This work aimed at using fucoidan as matrix of inhalable microparticles that associate two first-line antitubercular drugs, for an application in pulmonary tuberculosis therapy. Fucoidan is composed of fucose and sulphated sugar residues, moieties described as being recognised by surface receptors of alveolar macrophages, which host mycobacteria. Inhalable fucoidan microparticles loaded with antitubercular drugs were successfully produced with high association efficiencies of either isoniazid (95%) or rifabutin (81%). The microparticles evidenced no cytotoxicity on lung epithelial cells (A549). However, rifabutin-loaded microparticles showed a certain degree of toxicity on macrophage-like cells (THP-1) at the highest tested concentration (1 mg/mL). Furthermore, microparticles showed favourable aerodynamic properties for deep lung delivery (MMAD 2.0-3.8 µm) and, thus, show potential for an application as inhalable tuberculosis therapy.

In Vitro Effectiveness of Microspheres Based on Silk Sericin and Chlorella vulgaris or Arthrospira platensis for Wound Healing Applications

Some natural compounds have recently been widely employed in wound healing applications due to their biological properties. One such compound is sericin, which is produced by Bombix mori, while active polyphenols, polysaccharides and proteins are synthetized by Chlorella vulgaris and Arthrospira platensis microalgae. Our hypothesis was that sericin, as an optimal bioactive polymeric carrier for microencapsulation process, could also improve the regenerative effect of the microalgae. A solvent-free extraction method and spray drying technique were combined to obtain five formulations, based on algal extracts (C. vulgaris and A. platensis, Chl and Art, respectively) or silk sericin (Ser) or their mixtures (Chl-Ser and Art-Ser). The spray drying was a suitable method to produce microspheres with similar dimensions, characterized by collapsed morphology with a rough surface. Art and Art-Ser showed higher antioxidant properties than other formulations. All microspheres resulted in cytocompatibility on fibroblasts until 1.25 mg/mL and promoted cell migration and the complete wound closure; this positive effect was further highlighted after treatment with Art and Art-Ser. To our surprize the combination of sericin to Art did not improve the microalgae extract efficacy, at least in our experimental conditions.

Preparation, in vitro characterization, and in vivo pharmacokinetic evaluation of respirable porous microparticles containing rifampicin

This study aimed to prepare and evaluate rifampicin microparticles for the lung delivery of rifampicin as respirable powder. The microparticles were prepared using chitosan by the spray-drying method and evaluated for aerodynamic properties and pulmonary drug absorption. To control the drug release, tripoly-phosphate in different concentrations 0.6, 0.9, 1.2, and 1.5 was employed to get a sustained drug release profile. The microparticles were evaluated for drug loading, % entrapment efficiency, tapped density, morphological characteristics, and in vitro drug release studies. Aerosol properties were determined using the Andersen cascade impactor. Porous microparticles with particle sizes (d_0.5) less than 10 μm were obtained. The entrapment of rifampicin in microparticles was up to 72%. In vitro drug release suggested that the crosslinked microparticles showed sustained release for more than 12 hrs. The drug release rate was found to be decreased as the TPP concentration was increased. The microparticles showed a fine particle fraction in the range of 55–63% with mass median aerodynamic diameter (MMAD) values below 3 μm. The in vivo pulmonary absorption of the chitosan microparticles suggested a sustained drug release profile up to 72 hrs with an elimination rate of 0.010 per hr. The studies revealed that the spray-dried porous microparticles have suitable properties to be used as respirable powder in rifampicin delivery to the lungs.