Advancements in the Design and Development of Dry Powder Inhalers and Potential Implications for Generic Development

Dry powder inhalers (DPIs) are drug-device combination products where the complexity of the formulation, its interaction with the device, and input from users play important roles in the drug delivery. As the landscape of DPI products advances with new powder formulations and novel device designs, understanding how these advancements impact performance can aid in developing generics that are therapeutically equivalent to the reference listed drug (RLD) products. This review details the current understanding of the formulation and device related principles driving DPI performance, past and present research efforts to characterize these performance factors, and the implications that advances in formulation and device design may present for evaluating bioequivalence (BE) for generic development.

A full scale tracing study of "ghost peaks" encountered in impurity analysis of budesonide based on experimental operation inspection-LC/MS fingerprint- mechanism based stress studies integrated strategy

Budesonide is an active pharmaceutical ingredient used in various dosage forms of finished products for the treatment of asthma. During the process of drug development, unbiased analysis of related substances is of utmost significance for both pharmaceutical research and quality control purposes. In this work, official method documented in the United States Pharmacopoeia was selected to determine the related substances of budesonide considering the pros and cons of critical chromatographic parameters, compared to the European Pharmacopoeia. In doing so, several unpredictable interference peaks, namely "ghost peaks", were observed occasionally during analysis. A strategy which integrated information derived from experimental operation inspection, LC/MS fingerprint analysis and mechanism based stress studies was then proposed for comprehensively and quickly exploring those non-degradable and degradable peaks. Some ghost peaks were found to originate from nylon syringe filter, illumination and alkali borosilicate glass HPLC vials. Besides, degradation pathways under alkaline conditions were also unravelled through LC-MS qualitative analysis. Overall, an optimization of the analytical methodology based on the United States Pharmacopoeia for its application in impurity analysis of budesonide and corresponding formulations was carried out with design of experiments, by which "ghost peaks" could be suppressed or prevented. The results obtained herein are not only crucial to studies on budesonide's stability or degradation kinetics but also contribute to clarify the impurity research of other drugs. This article is protected by copyright. All rights reserved.

Engineering of levodopa inhalable microparticles in combination with leucine and dipalmitoylphosphatidylcholine by spray drying technique

The aim of this work was to study the effect of concomitant use of leucine and dipalmitoylphosphatidylcholine, in different ratios, on aerosolization performance of levodopa. Three-component formulations were selected based on a central composite design using percentages of leucine and dipalmitoylphosphatidylcholine as the independent variables. Particle size, surface roughness index, surface phosphorus and fine particle fraction were considered as dependent variables in the model. The spray dried samples were also characterized to determine their particle shape and solid state nature. levodopa was spray dried with 10-40% w/w of the excipients to prepare two- or three-component formulations. A crystalline nature was determined for levodopa in all samples spray dried from water:ethanol (30:70 v/v). Roughness in surface of the processed particles increased with increasing total concentration of the excipients, specially above 25% w/w. Analysis of phosphorus on the surface demonstrated that three-component formulations prepared with combination of 12.5% w/w leucine had the highest amount of dipalmitoylphosphatidylcholine in the surface, regardless of its percentage used in the initial feed. A combination of 12.43% w/w of leucine and 9.80% w/w of dipalmitoylphosphatidylcholine used in formulation exhibited the highest fine particle fraction (72.63%). It can be concluded that spray drying of levodopa with a suitable combination of both excipients leads to production of a three-component formulation of crystalline levodopa, with an aerosolization performance which is significantly higher than two-component formulations composed of the drug with either leucine or dipalmitoylphosphatidylcholine.

Engineered mucoadhesive microparticles of formoterol/budesonide for pulmonary administration

In the present study, a multi-component system comprised of dipalmitylphospatidylcholine (DPPC), Chitosan, Lactose, and L-Leucine was developed for pulmonary delivery. Microparticles were engineered by the spray drying process and the selection of the critical parameters was performed by applying experimental design. The microcarriers with the appropriate size and yield were co-formulated with two active pharmaceutical ingredients (APIs), namely, Formoterol fumarate and Budesonide, and they were further investigated. All formulations exhibited spherical shape, appropriate aerodynamic performance, satisfying entrapment efficiency, and drug load. Their physicochemical properties were evaluated using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), and Differential Scanning Calorimetry (DSC). The aerodynamic particle size characterization was determined using an eight-stage Andersen cascade impactor, whereas the release of the actives was monitored in vitro in simulated lung fluid. Additional evaluation of the microparticles' mucoadhesive properties was performed by ζ-potential measurements and ex vivo mucoadhesion study applying a falling liquid film method using porcine lung tissue. Cytotoxicity and cellular uptake studies in Calu-3 lung epithelial cell line were conducted to further investigate the safety and efficacy of the developed formulations.

Dextran Microparticulate Inhalable Dry Powder for the Treatment of Cystic Fibrosis and Mucopolysaccharidosis

BACKGROUND

Cystic Fibrosis (CF) is a genetic disease which affects the patient's lungs, pancreas, liver, kidney and intestine and lacks sulfatase enzyme, leading to mucopolysaccharidosis. Colistin sulfate acts by interacting with phospholipids of bacterial cell membranes. Sulfatase enzyme reduces the high levels of sulfated glycosaminoglycans and glycolipids by the hydrolysis of sulfate esters in lysosome.

OBJECTIVE

The aim of the present investigation was to prepare and evaluate dextran microparticulate inhalable dry powder for the efficient targeting of colistin sulfate at affected area of lung without causing the side effects in the treatment of CF and mucopolysaccharidosis.

METHODS

Microparticulate dry powder was prepared by the lyophilization method and evaluated for particle size, % yield, % drug content, solid state characterization, in-vitro lung deposition study, and in-vitro drug release study.

RESULTS

Particle size, % yield and % drug content were found to be 4.03 ± 0.196 µm, 94.02 % and 99.45 ± 0.015% respectively. Bulk density, tapped density, hausner's ratio, carr's index and angle of repose of optimized batch were found to be 0.216 ± 0.025 g/cm³, 0.236 ± 0.035 g/cm³, 1.09 ± 0.026, 8.47 ± 0.025 % and 26.10 ± 0.029˚ respectively. A fine particle fraction, fine particle dose, mass median aerodynamic diameter, geometric standard deviation and emitted dose were found to be 66.78%, 16.45 mg, 4.89 µm, 1.32 and 246.33 mg respectively. The % CDR of optimized batch was found to be 96.12 ± 0.049 % at 24 h.

CONCLUSION

Based on the obtained results, we conclude that dextran microparticulate inhalable dry powder might be suitable carrier for the delivery of colistin sulfate and sulfatase in combination via pulmonary route for the treatment of cystic fibrosis and mucopolysaccharidosis.

A review on recent technologies for the manufacture of pulmonary drugs

This review discusses recent developments in the manufacture of inhalable dry powder formulations. Pulmonary drugs have distinct advantages compared with other drug administration routes. However, requirements of drugs properties complicate the manufacture. Control over crystallization to make particles with the desired properties in a single step is often infeasible, which calls for micronization techniques. Although spray drying produces particles in the desired size range, a stable solid state may not be attainable. Supercritical fluids may be used as a solvent or antisolvent, which significantly reduces solvent waste. Future directions include application areas such as biopharmaceuticals for dry powder inhalers and new processing strategies to improve the control over particle formation such as continuous manufacturing with in-line process analytical technologies.

Formulation and Characterization of Nanocluster Ceftazidime for the Treatment of Acute Pulmonary Melioidosis

Melioidosis is an infectious disease caused by Burkholderia pseudomallei. The disease is responsible for a high proportion of human pneumonia and fatal bacteremia in the endemic areas of the world and is highly resistant to most commonly available antibiotics. Studies have shown that prophylactic antibiotic treatment, when administered 24 h following bacterial challenge, can prevent infection in a murine model. Prophylactic treatment against this disease using a pulmonary antibiotic formulation has not previously been examined, but may reduce the number of treatments required, allow for the delivery of higher doses, eliminate the need for intravenous administration, and help to minimize systemic side effects. Ceftazidime was formulated as a dry powder aerosol suitable for pulmonary delivery using previously developed NanoCluster dry powder technology. Pharmacokinetics of aerosolized ceftazidime was analyzed in a mouse model. This study demonstrates that ceftazidime can be formulated using NanoCluster technology as a dry powder aerosol suitable for pulmonary delivery to humans. We have also demonstrated the retention of nebulized ceftazidime in mouse lungs for up to 6 h after exposure. The results indicate that this treatment may be useful as a prophylactic treatment against melioidosis. Future work will examine the efficacy of this treatment against B. pseudomallei aerosol challenge.

Feasibility of highly branched cyclic dextrin as an excipient matrix in dry powder inhalers

We investigated the feasibility of highly branched cyclic dextrin (HBCD) as an excipient matrix in dry powder inhalers (DPIs). The fine particles of HBCD and HBCD/active pharmaceutical ingredients (APIs) were prepared by spray-drying an ethanol-aqueous solution containing HBCD. The particle size of spray-dried HBCD itself was approximately 3.0μm with a wrinkled shape. Solid-state fluorescence emission spectroscopy of 1-naphthoic acid (1-NPA) showed that it was dispersed in a molecular dispersion/solid solution, if the model compound of 1-NPA was spray-dried with HBCD. Powder X-ray diffraction and differential scanning calorimetry indicate that 1-NPA was in the amorphous state after spray-drying with HBCD, which is confirmed by the fluorescence measurements, 1-NPA could be incorporated into HBCD. When the antimycobacterial agent, rifampicin, was spray-dried with HBCD for the purpose of pulmonary administration, the emitted dose and fine-particle fraction of the spray-dried particles of rifampicin with HBCD were 95.7±1.7% and 39.5±5.7%, respectively. The results indicated that HBCD possessed a high potential as an excipient in DPIs, not only by molecular association of API molecules with HBCD, but also by that of API fine crystals.

Sonocrystallization and sonofragmentation

The application of ultrasound to crystallization (i.e., sonocrystallization) can dramatically affect the properties of the crystalline products. Sonocrystallization induces rapid nucleation that generally yields smaller crystals of a more narrow size distribution compared to quiescent crystallizations. The mechanism by which ultrasound induces nucleation remains unclear although reports show the potential contributions of shockwaves and increases in heterogeneous nucleation. In addition, the fragmentation of molecular crystals during ultrasonic irradiation is an emerging aspect of sonocrystallization and nucleation. Decoupling experiments were performed to confirm that interactions between shockwaves and crystals are the main contributors to crystal breakage. In this review, we build upon previous studies and emphasize the effects of ultrasound on the crystallization of organic molecules. Recent work on the applications of sonocrystallized materials in pharmaceutics and materials science are also discussed.

NanoClusters surface area allows nanoparticle dissolution with microparticle properties

Poorly water-soluble drugs comprise the majority of new drug molecules. Nanoparticle agglomerates, called NanoClusters, can increase the dissolution rate of poorly soluble compounds by increasing particle surface area. Budesonide and danazol, two poorly soluble steroids, were studied as model compounds. NanoCluster suspensions were made using a Netzsch MiniCer media mill with samples collected between 5 and 15 h and lyophilized. Differential scanning calorimetry (DSC) and powder X-ray Diffraction were used to evaluate the physicochemical properties of the powders, and Brunauer, Emmett and Teller (BET) analysis was used to determine surface area. Scanning electron microscopy confirmed NanoClusters were between 1 and 5 μm. NanoCluster samples showed an increase in dissolution rate compared with the micronized stock and similar to a dried nanoparticle suspension. BET analysis determined an increase in surface area of eight times for budesonide NanoClusters and 10-15 times for danazol NanoClusters compared with the micronized stock. Melting temperatures decreased with increased mill time of NanoClusters by DSC. The increased surface area of NanoClusters provides a potential micron-sized alternative to nanoparticles to increase dissolution rate of poorly water-soluble drugs.