Formulation and Characterization of Polysaccharide Microparticles for Pulmonary Delivery of Sodium Cromoglycate

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.

Sodium hyaluronate dry powder inhalation in combination with sodium cromoglycate prepared using optimized spray drying conditions

Sodium hyaluronate (SHA) is an anti-inflammatory and protective agent against bronchoconstriction, and sodium cromoglicate (SCG) prevents exercise-induced bronchoconstriction and inflammation. Based on the pharmacological properties of both substances, this study aimed to develop a dry powder inhaler (DPI) of SHA alone and in combination with SCG. The target of the study was to develop flowable formulations without any surfactants by using the spray drying method. To obtain respirable SHA and SCG:SHA particles, variables of the spray dryer, such as inlet temperature, atomized air flow, and feed solution, were changed. The particles 1-8 μm in size were produced with high yield by spray drying and increasing the ethanol percentage of the feed solution (60%), which is the most remarkable parameter. After that, physicochemical characterizations were performed. The aerosol performance of DPI formulations prepared using lactose was evaluated using Handihaler® DPI. The fine particle fraction (FPF) was 36% for the SHA formulation, whereas it was 52 and 53% for SCG and SHA, respectively, in the SCG:SHA formulation. Consequently, both particles were produced reproducibly by spray drying, and inhaled SHA and SCG:SHA dry powder formulations were developed due to their high FPF and flowability with lactose.

Polysaccharide-based formulations as potential carriers for pulmonary delivery - A review of their properties and fates

Polysaccharides can be elite carriers for therapeutic molecules due to their versatility and low probability to trigger toxicity and immunogenic responses. Local and systemic therapies can be achieved through particle pulmonary delivery, a promising non-invasive alternative. Successful pulmonary delivery requires particles with appropriate flowability to reach alveoli and avoid premature clearance mechanisms. Polysaccharides can form micro-, nano-in-micro-, and large porous particles, aerogels, and hydrogels. Herein, the characteristics of polysaccharides used in drug formulations for pulmonary delivery are reviewed, providing insights into structure-function relationships. Charged polysaccharides can confer mucoadhesion, whereas the ability for specific sugar recognition may confer targeting capacity for alveolar macrophages. The method of particle preparation must be chosen considering the properties of the components and the delivery device to be utilized. The fate of polysaccharide-based carriers is dependent on enzyme-triggered hydrolytic and/or oxidative mechanisms, allowing their complete degradation and elimination through urine or reutilization of released monosaccharides.

Development of a Carrier-Free Dry Powder Ofloxacin Formulation With Enhanced Aerosolization Properties

Tuberculosis (TB) is a serious infectious disease that affects more than new 10 million patients each year. Many of these cases are resistant to first-line drugs so second-line ones, like fluoroquinolones, need to be incorporated into the therapeutic. Ofloxacin (OF) is a fluoroquinolone which demonstrates high antibiotic activity against the bacteria that causes TB (M. tuberculosis). In this work, ionic complexes, composed by hyaluronic acid (HA) and OF, with different neutralization degrees, were prepared and processed by spray drying (SD) to obtain powders for inhalatory administration. Combining a formulation with high neutralization degree, high SD atomization air flowrate and the use of a high-performance collection cyclone, very good process yields were obtained. Carrier-free formulations with a loading of 0.39-0.46 g_OF/g_powder showed excellent emitted, fine particle, and respirable fractions for capsule loadings of 25 and 100 mg. The ionic complexes demonstrated higher mucoadhesion than pure OF and HA. The best formulation did not affect CALU-3 cell viability up to a dose 6.5 times higher than the MIC₉₀ reported to treat multi-drug resistant TB.

Repositioning Chromones for Early Anti-inflammatory Treatment of COVID-19

The COVID-19 pandemic is posing an unprecedented sanitary threat. In the absence of specific vaccines and anti-SARS-CoV-2 drugs, medicines that may assist in tackling the emergency and limiting the high number of fatalities are urgently needed. The repositioning of available drugs to treat COVID-19 is the only and rapid option in the face of the lack of direct antiviral agents and vaccines available. In this light it is important to focus on available drugs, which, based on their pharmacodynamics, could plausibly attenuate viral growth as well as COVID-19’s worst complications. This is the case of chloroquine and tocilizumab which seem to limit virus replication and the severity of interstitial pneumonia, respectively. However, these treatments, particularly those aimed at containing inflammation, are still reserved for the most severe cases. This commentary elaborates on the pharmacological rationale of repositioning the mast cell stabilizer chromones as an adjunctive treatment for SARS‐CoV‐2 infection, and proposes their practical clinical testing as an early, safe, and cost-effective anti-inflammatory intervention in COVID-19 to limit the eventual secondary progression toward life-threatening respiratory complications.

Nanoporous Microsponge Particles (NMP) of Polysaccharides as Universal Carriers for Biomolecules Delivery

Different polysaccharides-namely dextran, carboxymethyl dextran, alginate, and hyaluronic acid-were compared for the synthesis of nanoporous microsponges particles (NMPs) obtained from a one-pot self-precipitation/cross-linking process. The morphologies and sizes of the NMPs were evaluated comparatively with respect to polymer-to-polymer and cross-linker solvents (water-based vs. DMSO). We found that the radial distribution of the polymer in the near-spherical NMPs was found to peak either at the core or in the corona of the particle, depending both on the specific polymer or the solvent used for the formation of NMPs. The NMP porosity and the swelling capability were evaluated via scanning electron microscopy (SEM). The degradation study indicated that after 10 h incubation with a reducing agent, approximately 80% of the NMPs were disassembled into soluble polysaccharide chains. The adsorption and release capacity of each type of NMP were evaluated using fluorescently labeled bovine serum albumin and lysozyme as model proteins, highlighting a release time typically much longer than the corresponding adsorption time. The dependence of the adsorption-release performance on pH was demonstrated as well. Confocal microscopy images allowed us to probe the different distribution of labeled proteins inside the NMP. The safety and non-cytotoxicity of NMPs were evaluated after incubation with fibroblast 3T3 cells and showed that all types of NMPs did not adversely affect the cell viability for concentrations up to 2.25 μg/mL and an exposure time up to 120 h. Confocal microscopy imaging revealed also the effective interaction between NMPs and fibroblast 3T3 cells. Overall, this study describes a rapid, versatile, and facile approach for preparing a universal non-toxic, nanoporous carrier for protein delivery under physiological conditions.

Optimization of Ciprofloxacin Hydrochloride Spray-Dried Microparticles for Pulmonary Delivery Using Design of Experiments

Ciprofloxacin is a broad-spectrum antibiotic for treatment of pulmonary diseases such as chronic obstructive pulmonary disease and cystic fibrosis. The purpose of this work was to rationally study the spray drying of ciprofloxacin in order to identify the formulation and operating conditions that lead to a product with aerodynamic properties appropriate for dry powder inhalation. A 2^4 - 1 fractional factorial design was applied to investigate the effect of selected variables (i.e., ciprofloxacin hydrochloride (CIP) concentration, drying air inlet temperature, feed flow rate, and atomization air flow rate) on several product and process parameters (i.e., particle size, aerodynamic diameter, moisture content, densities, porosity, powder flowability, outlet temperature, and process yield) and to determine an optimal condition. The studied factors had a significant effect on the evaluated responses (higher p value 0.0017), except for the moisture content (p value > 0.05). The optimal formulation and operating conditions were as follows: CIP concentration 10 mg/mL, drying air inlet temperature 110°C, feed volumetric flow rate 3.0 mL/min, and atomization air volumetric flow rate 473 L/h. The product obtained under this set had a particle size that guarantees access to the lung, a moisture content acceptable for dry powder inhalation, fair flowability, and high process yield. The PDRX and SEM analysis of the optimal product showed a crystalline structure and round and dimpled particles. Moreover, the product was obtained by a simple and green spray drying method.

Carrier free indomethacin microparticles for dry powder inhalation

The present studies were designed to evaluate inhalatory microparticles carrying indomethacin (IN) for potential local (specific and non-specific bronchial inflammatory asthma responses) and systemic treatments (joint inflammation, rheumatoid arthritis and osteoarthritis pain) by optimizing microparticle properties, characterizing their lung deposition, drug release, evaluating cytotoxicity and also pharmacological effect in vitro. The acidic groups of IN were complexed with the cationic groups of the polyelectrolyte polylysine in order to increase the drug water compatibility. The polylysine/indomethacin ratio was fixed and the pH was adjusted in different formulations. Microparticles were obtained by spray drying using a relatively high atomization air flowrate (742 L/min) and a high-performance cyclone in order to optimize the production of microparticles with adequate attributes for inhalatory delivery. The produced microparticles exhibited high process yield and IN loading, volumetric mean diameters smaller than 5 μm and narrow particle size distributions. According to demonstrated aerosolization performance, the powders were suitable for inhalatory indomethacin local and systemic treatments. Emitted fraction was higher than 90%, the MMAD was around 3 μm and the GSD lower than 3. The respirable fraction for particles with aerodynamic diameters smaller than 5 μm was around 29% while for particles with aerodynamic diameters smaller than 3 μm the value was around 17%. The addition of lactose as carrier worsened the aerodynamic performance of the microparticles. The developed powdered systems got wet and dissolved quickly and presented higher release rates respect to pure IN in simulated lung physiological conditions. Furthermore, the assays performed in RAW 264.7 cell line showed that the microparticles exhibited the same anti-inflammatory capability as the pure drug. The developed particles did not affect the RAW 264.7 cell viability. In conclusion, a promising powder formulation for DPIs has been developed to treat, locally and systemically, inflammatory diseases.