IA 2017 | Posters

You can access the abstracts and presentations of previous Inhalation Asia events on this page: www.inhalationasia.org. Inhalation Asia is committed to open access to its conference archive. Access to this information is free of charge, but does require you to register on our database and to agree to respect the copyrights of the authors. Please make reference to Inhalation Asia every time you make use of the material you download.

The full list of posters with abstracts and presentation materials will be available for download by registered participants closer to the beginning of IA17, late August 2017. It will be available free of charge. Note that no printed book of abstracts will be given to participants.

Influence of airflow with generation output over a range of Pre-clinical nebuliser comparisons to allow more effective decision making on device selection
Simon Moore

The generation output from 25 different nebulisers across >120 pre-clinical inhalation studies were reviewed. The output from the nebuliser was compared against 3 configurations:- 1) All supply air through the nebuliser 2) Supply air through the nebuliser and supplementary diluent air 3) Supply air through the nebuliser and an open system relying on the extract to draw the air past the animals The 50 studies for the Medex Aeromist nebuliser gave a generation output (8-24 mL/hr) over a range of airflows (15 to 50 L/min). The R2 value for Configuration 1 was 0.8599 over the range of aerosol and formulation concentrations and compositions. The R2 value increased to 0.8815 for configuration 2 and 0.9522 for configuration. Data from 20 other jet nebulisers showed a similar relationship unless limited by the maximum generation airflow that can be achieved through the device. An assessment was also conducted to establish whether multiple jet nebuliser used concurrent influenced the output (6 studies). This established that the generation output was similar to that presented for single nebuliser exposure systems. The generation output from 4 different mesh nebulisers were also evaluated across 21 studies and varied between 6 to 24 mL/hour at the same airflow depending on the formulation (solution or suspension) and formulation strength. The output decreased with increasing formulation strength but was independent of the number of nebulisers attached to the exposure system. Throughout this data evaluation, the overall test article usage from individual exposures varied <5%. Any change in the generation output rate would be observed in a change in the volume of formulation in the nebuliser. In conclusion, the generation output from jet nebulisers was not influenced by the formulation composition but the inclusion of supplementary air and the use of an open exposure system. The generation output from the mesh nebulisers was widely variable depending on formulation and formulation strength.


Improved animal welfare standards in large animal species allows extended periods of inhalation dosing
Simon Moore

Envigo is a leading non-clinical CRO for respiratory safety assessment. There is an increasing demand for this expertise as interest in inhaled delivery of drugs increases. Inhalation administration is the route of choice for a significant number of drugs, notably treatments for asthma and other respiratory tract disorders; and also for a widening range of non-respiratory diseases, as a means of avoiding extensive first-pass metabolism. This poster focuses on improvements in animal welfare standards for large animal species that allow extended periods of inhaled delivery and thus provide greater safety margins when drugs progress to the clinic. The methodology for dogs employs a new type of minimal restraint rather than the traditionally used and restrictive sling method. The success of this technique lies in the effective daily training of dogs to the inhalation dosing suite, face mask, harness and supplied air over a preceding 14 day period prior to any animal exposure. This methodology minimises stress and discomfort to the animals involved, allowing longer periods of dose delivery, improving study conduct and easier interpretation of results. So far Envigo has been able to administer inhaled dose continuously for up to six hours. The methodology for non-human primates involves a pre-dose acclimatisation period to the inhalation dosing suite, face mask and restraint chair; in addition, other "distraction methods" are used. Toys and videos are provided with the training in advance of the inhalation dose acclimatisation procedures. The primates usually play with the toys for a few days and then prefer to watch the video cartoons. The fixation the primates have with the cartoons allows for easier training to the inhalation dosing procedures, making extended periods of dosing possible. A similar approach can also be applied for the habituation and inhalation exposure of mini-pigs, a species increasingly used for respiratory safety assessment studies. In this species, rather than using toys and videos to aid acclimatisation, the mini-pigs are given a small edible treat in advance and following each session.


Rat respiratory minute volume comparison of snout-only plethysmography studies collected during the acclimatisation phase
Simon Moore

Prior to the exposure phase of a snout-only plethysmography study, the animals were acclimatisedto the restraint tube procedure over a period of days. The aim was to minimise stress-related elevations in respiratory minute volume (RMV) values, which may mask potential effects of administered test material. Pre-dose measurements of tidal volume (TV), respiration rate (RR) and RMV were collated over the last 2 years (232 data points) to ascertain whether there were any differences in rat strain (Han Wistar (HW) and Sprague Dawleys (SD)) or type of chamber (flow through (FT) or flow past (FP)). There was no discernible difference in RMV with the type of strain irrespective of bodyweight. Both data sets had a similar level of variability. 116 from 152 (76%) HW animals had an RMV greater than predicted1. This is in contrast with the SD animals, from which only 70% (56 from 80) were above that predicted. The type of chamber made a difference to the RMV. The RMV values for the 200-300g bodyweight range gave a statistical difference (p<0.001) for the FT chambers (266 mL/min) compared with the FP (219 mL/min) chambers. There was no statistical difference in TV (1.48 mL/min for FT and 1.48 mL/min for FP). However, there was a statistical difference (p<0.001) in RR (176 breathes/min for FT and 151 breathes/min for FP). Mean bodyweights were 260g for FT and 265g for the FP for this range. Comparing the RMVs against the equivalent rat data used in the Alexander equation1 found that this dataset produced RMV values (55%) that were lower than predicted, suggesting that this equation underestimates the RMV for rats. In conclusion, the type of strain makes no difference to the RMV. However, the FT chamber gave higher RR (and RMV) values than the FP chamber. Conducting a direct comparison with the Alexander et al RMV equation1 found that the majority of the data points presented gave RMV values lower than predicted and species specific RMV equation is necessary. 1 Alexander DJ et al. (2008). Inhal. Tox., 20, 1179-1189.


Test article conservation during early in-vivo respiratory safety assessment studies
Simon Moore

In both clinical and non-clinical environments inhaled drug delivery to conscious subjects has always required larger quantities of the test article than other routes of administration. This is a common issue for dry powder and liquid droplet formulations due to inefficiencies that occur in both the aerosol generation methodology used and within the delivery systems needed for human or animal exposures. Financing such losses, particularly when conducting in vivo non-clinical studies involving high exposure concentrations, can result in delayed product development or a complete failure to progress promising molecules. Increasing the efficiency of test article usage may enable the completion of critical proof of concept and IND enabling inhalation investigations with significantly smaller quantities of an active moiety than would be necessary when employing standard laboratory techniques. This can be especially important early in test article development when the quantities available are commonly limited and produced at the highest unit cost due to lab scale manufacture. The most extreme drug manufacturing costs are generally associated with the development of large molecule based pharmaceuticals. In many instances a contract research organization will be expected to work within limits of test article availability that are defined by the Customer at program inception and unconnected to requirements based on inhalation delivery convention. Under these circumstances it is necessary to develop methods that will meet all required end points within that availability. This poster describes techniques that have been found to be effective when test article conservation in regulatory toxicology studies has been essential to the completion of a product development phase within tight drug availability and temporal budgets. The techniques described include methods of aerosol generation, exposure system design and delivery and equipment miniaturization.


Capsule based aerosol generator (CBAG) – validation in a rat model of LPS-induced non allergic pulmonary inflammation
Simon Moore

Intratracheal (IT) insufflation is the principal method of delivery of inhaled drug substances to conscious non-clinical species in early drug development. However, this technique achieves particulate deposition dissimilar to conscious inhaled delivery and can produce artefactual toxicological and pharmacological results. The CBAG was developed1 as an alternative to IT insufflation whilst also providing representative inhalation exposure. This study demonstrates the effectiveness of the CBAG in the rat model of LPS-induced non-allergic airway inflammation. Rats were exposed to 0.01, 0.1 or 1.0 mg/kg of inhaled fluticasone propionate (FP) over a 20 minute period using nominally 1 mg filled hydroxypropyl methyl cellulose size 2 capsules at blend strengths of 1, 10 and 100% w/w of FP respectively. Two concurrent control groups were exposed to lactose only using the same regime. Twenty minutes after the end of the inhalation exposure the animals were challenged with either aerosolised LPS (0.1 mg/mL), for the FP groups and one control group, or 0.9% w/v saline (second control group) for 30 minutes. Rats were euthanized four hrs following the challenge and a bronchoalveolar lavage (BAL) investigation performed. A BAL total and differential cell count was used to evaluate the efficacy of FP. Delivered doses of 0.0103, 0.117 and 0.863 mg/kg were achieved, which were within 14% of target. This resulted in a dose dependent inhibition of BAL neutrophils of 40%, 79% and 98% respectively compared with the lactose/LPS control group. In conclusion, the results give confidence that the CBAG is a viable alternative to IT methodology for studies in early drug development and it has the added advantage of producing results representative of inhaled exposures.


Practicalities of conducting Pre-clinical Inhalation toxicology studies
Simon Moore

The presentation will start be discussing the advantages or disadvantages of the main methods of calculating pre-clinical doses from clinical doses and how this relates to the practicalities of inhalation dosing. Pre-clinical inhalation doses are based on the aerosol concentration, respiratory minute volume, exposure duration, inhalable fraction and bodyweight. The aerosol concentration can be achieved using different types of aerosol generation. The principle liquid, suspension, micronized or novel powder manufactured techniques will be discussed including how it relates to the pre-clinical and clinical formulations. The respiratory minute volume can be determined practically but depending on the method, it has limitations due to the data quality (examples will be presented). As a result known algorithms are normally presented. This use of these algorithms and when to use or not use will be discussed. From an animal welfare perspective, the exposure duration should be as a short as practical to achieve the objective and target inhaled dose. However, the inter-relationship between the formulation, aerosol concentration and exposure duration often results in long exposure durations. Rodents and rabbits can be successfully dosed by snout-only exposure for 6hrs but there are more practical limitations with primates, dogs and mini-pigs even by mask exposure. The main concepts of maximising the exposure duration to achieve animal compliance will be presented. Samples to determine the inhalable fraction are required, like with the aerosol concentration, to achieve regulatory acceptance. Sample methodologies will be presented including best practice.


Dose Output Rate Assessment of Several Respiratory Formulations From a Novel Handheld Mesh Nebulizer
John Pritchard

The InnoSpire Go mesh nebulizer has been developed as an easy to use mesh nebulizer for the delivery of common nebulized drugs. General purpose nebulizers are used by patients with ailments such as asthma, chronic obstructive pulmonary disease and cystic fibrosis, therefore these nebulizers must aerosolize a range of drugs. We have previously presented particle size data for the InnoSpire Go mesh nebulizer with a range of drugs (Slator et al, proceedings of RDD Europe 2017), here we present output data for 5 of these drugs. Production equivalent InnoSpire Go nebulizers were tested with 5 different drugs using a breathing simulator producing a breathing pattern of 500 mL Tv, 1:1 I:E ratio, and 15 breaths per minute. Three nebulizers were tested in triplicate with each drug. Nebulizers were weighed, loaded with the contents of the drug respule, reweighed and connected via a filter to the breathing simulator. Nebulizers were run until the end of treatment and reweighed. End of treatment was detected automatically by the nebulizer. Aerosol output deposited onto filters was quantified by high performance liquid chromatography to assess delivery of the active drug substance. Results were converted into volumes to allow easy comparison between drugs. Loaded and emitted masses were calculated from the recorded nebulizer weights, and converted to volumes by dividing the masses by the density of the drugs tested. Results are displayed as drug and concentration tested, loaded volume; emitted volume; filter deposition, all in (mL) followed by [standard deviation]. Salbutamol sulphate (5 mg/2.5 mL, Salamol; IVAX Pharmaceuticals, Castleford, UK) = 2.65 [±0.04]; 2.34 [±0.05]; 1.19 [±0.03] mL: Ipratropium bromide (500 mg/2.0 mL, Atrovent; Boehringer Ingelheim, Ingelheim, Germany) = 2.09 [±0.02]; 1.85 [±0.04]; 0.93 [±0.02] mL: Sodium cromoglicate (20 mg/2 mL, Lomudal; Sanofi, Gentilly, France) = 2.08 [±0.04]; 1.80 [±0.04]; 1.01 [±0.02] mL: Dornase alfa (2500 U/2.5 mL, Pulmozyme; Roche, Basel, Switzerland) = 2.48 [±0.02]; 2.04 [±0.04]; 0.99 [±0.02]: Tobramycin (300 mg/4 mL, Bramitob; Chiesi Ltd, Manchester, UK) = 4.14 [±0.09]; 3.70 [±0.08]; 1.87 [±0.05]. The InnoSpire Go successfully nebulized all the drugs, with approximately half of the emitted aerosol deposited onto the inhalation filter during simulated breathing and with very little intra-drug variation across the nine tests completed with each drug. The InnoSpire Go nebulizer successfully delivered a range of drug formulations that are commonly used in the treatment of respiratory disease.


Formulation of inhaled antifungal agent as dry powder using spray freeze drying technology
Jenny Lam

Respiratory infections caused by fungus such as Apsergillus sp. have become an emerging focus of infectious diseases in recent years. With the growing number of patients with respiratory diseases such as chronic obstructive pulmonary disease (COPD) and pneumonia, it is expected that the number of patients with pulmonary aspergillosis will also increase in the coming years. The mainstay treatment of pulmonary aspergillosis involves the use of triazoles and amphotericin B for systemic administration. However, these antifungal agents are associated with severe side effects, erratic absorption and poor lung distribution. On the other hand, pulmonary delivery allows deposition of high drug concentrations at the site of infection and minimizes systemic exposure, hence reducing the risk of adverse effects. The aim of this study was to explore the potential of spray freeze drying (SFD) technology to produce inhaled powder formulation of voriconazole with high efficiency. SFD involves the atomization of liquid into fine droplets which are instantaneously frozen in a cryogenic liquid, followed by the freeze drying of samples which are sublimed at low temperature and pressure to form porous particles. In this study, -cyclodextrin was used to enhance the aqueous solubility of voriconazole, and the tert-butyl-alcohol (TBA) was used as a co-solvent. The effects of solute concentrations (2 to 8% w/v), composition of co-solvent (water or water/TBA at different ratios) and liquid feed flow rates during atomization (0.4 to 4 ml/min) on the aerosol properties of the powder formulations were examined. The results from laser diffraction and scanning electron microscope showed that SFD could produce spherical powders of voriconazole with relatively narrow particle size distribution. When water was used as the sole solvent, the particles appeared to be smooth on surface. However, the aerosol performance, evaluated by the Next Generation Impactor (NGI), showed that these formulations exhibited a relatively low fine particle fraction (FPF, fraction of powders with aerodynamic diameter below 5.0 m) of around 10%. The addition of TBA as co-solvent increase the porosity of the powders as well as the FPF to around 25-30%. Increasing the solute concentration from 2% to 8% reduced the aerosol performance, while varying the liquid feed flow rate did not have a major impact on the aerosol properties of the powders. The current study has demonstrated that the aerosol properties of SFD powders of voriconazole could be controlled by carefully manipulating the solute concentration and the solvent composition.


Spray blending to manufacture dry powder formulation for combination products
Alan Chang

There are different methods to manufacture dry powder for combination drug formulations (two or more active ingredients) with specific characteristics to tune the particle size, morphology, density, etc. The benefit of combining the active ingredients is that the patient only need to administer one product without the need to administer the drug combinations separately. For complex product formulation that contains two or more active ingredients, it is essential to be able to accurately control the drug content uniformity as well as other powder characteristics. One option is to use solid-solid batch mixing, in which pre-fabricated solids are mixed to form the combination drug product. However, spray blending can be used for a more continuous process to manufacture blended powder. This talk will review the advantages and challenges with the technology for spray blending that can be used to manufacture a blended powder product. The design of the nozzle, as well as process condition used to spray blend the formulated feedstock solution are crucial for control of particle size distribution, morphology, and content uniformity. The final dry powder manufactured can be used for a variety of applications, for both pharmaceutical and food industry. Unlike the batch processing for blending powders, the benefit of this system is that the particles are engineered to a specific particle characteristic while the active ingredients are being blended simultaneously.


Comparison between inhalation solution and suspension: The measurement of particle size distribution upon nebulization
Anny Shendl

Comparison between inhalation solution and suspension: The measurement of particle size distribution upon nebulization Fu Tao-Tao1, Wang Jian2,4, Tan Wen3,4, Liao Yong-Hong1,4 1Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100193, yhliao@implad.ac.cn; 2Shanghai Institute of Pharmaceutical Industry, Shanghai , 200437; 3South China University of Technology, Guangzhou, 510641; 4 Inhalation Drug Delivery Association of China (IDDA) Aerodynamic assessment and particle/droplet size distribution are compendial requirements for the quality characterization of nebulizer-generated aerosols. This work intended to perform a comparative measurement of particle size distribution between inhalation solutions and suspensions after nebulization using both Next Generation Pharmaceutical Impactor (NGI) and laser diffraction methods. Six types of PARI® jet nebulizers with different particle size ranges were utilized using compressed air at a flow rate of 6.0 L/min to generate the aqueous aerosols whereas a Ventolin inhalation solution and a budesonide suspension for inhalation (Pulmicort Respules) were used as the model formulations. The v volume median diameters (VMD) was measured using a Spraytec Laser Diffraction (Malvern instruments, UK) instrument whereas the mass median aerodynamic diameter (MMAD) was determined using an NGI (COPLEY Scientific, UK) at a flow rate 15 L/min. The mass of active substance collected in the mouthpiece and induction port, on each stage and on the back-up filter/external filter was determined using HPLC assays. Following the generation of aerosols of inhalation solution and suspension with PARI jet nebulizers, the VMD measured by Spraytec varied from 2.39 to 5.04 mm for both solution and suspension. For LC sprint2 and LC Family generated aerosols, the VMD were between 3.6 and 3.8 mm and almost identical between Ventolin and Pulmicort Respules. However, for the aerosols generated by JuniorBOY SX, Package SX or LC Plus, the VMD from the inhalation solution were between 4.88 and 5.04 mm whereas those from the suspension were between 4.11 and 4.47 mm, indicating that the budesonide suspension resulted in smaller VMD than the Ventolin solution upon nebulization. The JuniorBOY SX, Package SX or LC Plus generated aerosols were subjected to further aerodynamic assessment by NGI.

The MMAD values of aerosols from the inhalation solution were between 4.70 and 5.09 mm whereas those from the suspension ranged from 6.41 to 6.76 mm. The comparison of the data obtained from NGI and Spraytec led to different observations between the inhalation solution and suspension. For the inhalation solution, there was a strong correlation between cumulative size distribution data, which showed that there were no significant difference between MMAD and VMD values and a linear relationship (R2³ 0.995) between cumulative size distributions obtained from NGI and Spraytec. However, for the suspension formulation, the MMAD values were significantly larger than the VMD and the cumulative distributions obtained from NGI and Spraytec for the three nebulizers showed a weak correlation (R2£ 0.97). In conclusion, the present results demonstrated that the laser diffraction method is suitable for use as a simple alternative to impaction to characterize jet nebulizer generated aerosols of inhalation solutions but not suspension formulations.


A Comparison of the Chinese, European, US Pharmacopoeia Inhalation Chapters
Lee Nagao

The current Chinese Pharmacopoeia (ChP) went into effect on December 1, 2015. According to the CFDA, "the promulgation of the new edition of Chinese Pharmacopoeia marks the promotion of the level of China's drug use, production and supervision. It will drive the overall improvement of drug quality and play a significant role in ensuring drug safety and effectiveness for the public". Volume IV of the pharmacopoeia includes several chapters relevant to inhalation products: <0111>, <0112>, <0113> and <0951>. The pharmacopoeia also includes several monographs for specific inhalation drug products. This poster, developed by members of the International Pharmaceutical Aerosol Consortium on Regulation and Science (IPAC-RS) China outreach group, compares the requirements for inhalation products in the ChP with those in the European and United States Pharmacopoeia (Ph. Eur., USP, respectively), with focus on general requirements, and expectations for aerodynamic particle size distribution and delivered dose uniformity.


The effect of carrier particle size on flowability and dispersion performance of DPI formulations
Xiang-Yun Lu

This study investigates the effect of carrier size on the dispersion behavior of carrier-based dry powder inhaler (DPI) formulations. The formulations used in the study were blends of Inhalac® 70, Inhalac® 120 or Inhalac® 250 (LA70, LA120 or LA250) (Meggle, Wasserburg, Germany) and Inhalac® 400 (LA400 – median diameter by volume of <7.6μm) with fine particle ratios of 9.0, 8.8 and 10.2% respectively. Flow properties of the formulations were characterized by quantifying dynamic flow, bulk and shear properties using the FT4 Powder Rheometer (Freeman Technology Ltd. Tewkesbury, UK). Parameters including flow energy, aerated energy and shear stress were measured and presented. The blends were aerosolized using a laboratory-built inhalation device and the dispersion behavior analyzed using the Spraytec laser diffraction system (Malvern Instruments Ltd. Malvern, UK) at an airflow rate of 60 L/min. The fine particle fraction (FPF) below a threshold of 7.6 μm was obtained and recorded. In addition, a computational fluid dynamics (CFD) simulation was adopted to analyze the moving trajectories of the carrier particles. The results showed that as the size of the carrier lactose increased, the blends became more resistant to forced, dynamic flow and less sensitive to changes in powder flow rate. In addition, they became more permeable and transitioned into a state of improved flow. The formulations containing larger carrier particles (LA70 and LA120) exhibited improved dispersion performance. Even though the blend with smaller carrier particles (LA250) contained a higher fine particle ratio, it exhibited a poorer dispersion performance. The CFD simulations suggested that the smaller particles (LA250) experience fewer collisions in the device compared to the larger particles (LA70 and LA120). Therefore, the increase in particle size of the carrier lactose can improve the flow properties and the dispersion performance of DPI formulations in the present study. Further investigations into the relationship of powder flowability and dispersion, as well as the impact of device design, are planned.


Predicting Mouth-Throat Deposition of Aqueous Aerosols Delivered from Respimat® Inhaler
Xiangyin Wei

Predicting an inhaler’s performance in vivo can be beneficial during both innovator and generic drug product development. This can be achieved by incorporating realistic human mouth-throat (MT) models and inhalation profiles (IP) into in vitro inhaler testing. Previous studies have shown that in vitro – in vivo correlations (IVIVC) of lung deposition could be established for a series of different inhalers using these methods. In this study, we performed realistic in vitro testing using the Respimat® Soft Mist inhaler (RSMI) and compared the results with one of the few in vivo lung scintigraphy studies that were available (Brand et al., 2008). Methods: The study inhaler was the RSMI with a 0.84% w/v fenoterol hydrobromide aqueous formulation (formulation produced in house and not FDA approved). Three realistic MT models, the medium Virginia Commonwealth University (VCU) model, the medium Oropharyngeal Consortium (OPC) model, and the Alberta Idealized Throat (AIT) were selected for testing. The USP Induction Port was also tested for comparison. Realistic IPs were simulated to mimic the mean inhalation maneuvers of “untrained” and “trained” patients described in the reference lung scintigraphy study. The “untrained” IP is characterized with a peak inspiratory flow rate of 146.9 L/min, and 67.9 L/min for the “trained” IP. The MT, fitted with a low resistance filter at the tracheal exit, was attached to a programmable breath simulator. Test conditions were maintained at 25 °C and 50% RH. The RSMI was fired at the beginning of each simulated IP. After single dose actuation, the apparatus was dissembled and drug recovered by rinsing inhaler mouthpiece, MT and filter using deionized water and analyzed using HPLC. Three replicates were performed and MT deposition was reported as a % of the delivered dose (dose collected from MT and filter). Results: The mean (SD) in vitro MT deposition were 53.5(2.4)% for the VCU model, 63.1(2.0)% for the OPC model, and 53.1 (2.5) % for the AIT model, when RSMI was tested using the “untrained” IP. There was no statistically significant difference between the deposition observed for the VCU and AIT models, however, the OPC model deposition was significantly higher. These values compared with the reported in vivo MT deposition value of 55.9%. Using the “trained” IP, all three realistic models failed to predict the in vivo MT deposition, which was reported as 44.7%. The observed mean (SD) in vitro MT deposition was 22.9(1.5)%, 26.0(1.3)%, and 24.3(1.0)% for the VCU, OPC, and AIT models, respectively.

Finally, the USP Induction Port produced significantly lower MT deposition than all three realistic models using both the “untrained” and “trained” IPs, with mean (SD) values of 37.0(2.7)% and 15.8(0.4)%, respectively. Both the in vitro and in vivo studies showed MT deposition for RSMI that are dependent on inhalation flow conditions. Conclusions: IVIVC of MT deposition could be established for RSMI using realistic MT models using the “untrained” conditions. Further studies are needed to investigate the reason why all three realistic MT models failed to predict the in vivo MT deposition using the “trained” conditions.


Respirable powder formulation of pirfenidone with reduced phototoxic risk
Satomi Onoue

Pirfenidone (PFD) is clinically used for treatment of idiopathic pulmonary fibrosis; however, previous clinical studies demonstrated that orally-taken PFD often caused phototoxic skin responses in 51.4% of patients. Dry powder inhalation system of PFD might be efficacious for controlling skin distribution of PFD, possibly leading to reduced phototoxic risk. The present study aimed to develop novel respirable powder formulation of PFD (PFD-RP) for minimizing exposure of the skin to PFD and maximizing topical effects. Photobiochemical properties of PFD were examined with focus on UV absorption, generation of reactive oxygen species (ROS), lipid peroxidation, and DNA impairment. In vivo phototoxicity testing was conducted after oral administration of PFD (30–160 mg/kg). PFD-RP was prepared with a jet-mill, and in vivo pharmacological effects of PFD-RP were also assessed in experimental asthma/COPD model rats. Pharmacokinetic studies on PFD formulations were carried out after oral and intratracheal administration. PFD exhibited intense UVA/B absorption with molar extinction coefficient of 1,290 M-1・cm-1 and generated ROS, including singlet oxygen and superoxide, after exposure to simulated sunlight (Xe lamp, 250 W/m2). These photochemical data suggested the potent photoreactivity of PFD, which might be key trigger for phototoxic reactions. Based on the in vitro phototoxic assessments, PFD exhibited potent photoirritant risk, although in vitro photogenotoxic reaction of pirfenidone was negligible. Laser diffraction and cascade impactor analysis of newly developed PFD-RP, consisting of jet-milled PFD and lactose carriers, suggested its high dispersion and in vitro inhalation performance. Inhaled PFD-RP (0.3 mg-PFD/rat) could suppress antigen-evoked inflammatory events in experimental asthma/COPD model rats as evidenced by reduced infiltration of inflammatory cells and decrease of inflammation-related biomarkers in the pulmonary tissues. The PFD-RP at a pharmacologically effective dose could also reduce phototoxic potential of PFD because of its lower systemic exposure than that after oral administration of PFD at the phototoxic dose (160 mg/kg). From these findings, the PFD-based inhalation therapy would be an attractive alternative to current oral therapy of PFD with a better safety margin for clinical treatment of idiopathic pulmonary fibrosis.


In Vitro Evaluation of Aerosol Delivery between Soft Mist Inhaler and Pressurized Metered-Dosed Inhaler

Soft Mist Inhalers (SMI) do not necessitate the use of propellant, pneumatic or electrical power source to generate aerosols. They are easy-to-operate and -coordinate inhalers; however, whether the properties of SMI facilitate aerosol delivery has not been fully investifated. The present study aimed to compare the efficiency of SMI vs pressurized Metered-Dose Inhaler (pMDI) in various conditions through an in vitro model. SMI (2.5 µg / actuation of Tiotropium) was compared with pMDI (100 µg / actuation of Salbutamol) containing HFA propellant. The spray duration was recorded by a high speed camera (i-Speed 2, iX-Cameras Inc.) from the lateral side of the inhaler. To test the dose uniformity of both inhalers, the inhaler was directly connected to the filter used to collect the drug aerosol, and the suction flow rate was set at 30 L/min. In addition, a 10-stage MOUDI cascade impactor were used for aerodynamic particle sizing of aerosol particles generated by inhalers alone, inhalers with spacer, and inhalers with Valved Holding Chamber (VHC). Available particle cut-off diameters of MOUDI at 30 L/min sampling flow rate are 0.056, 0.10, 0.18, 0.32, 0.56, 1.0, 1.8, 3.2, 5.6 and 10 μm. Mylar filters (47mm) were used in the MOUDI as collection media. Drug aerosol collected on filters was eluted by distilled water and was quantitated by spectrophotometry. The results of video recording revealed that spray duration from the SMI was 8.4 times longer than from thepMDI (SMI: 1.43 sec; pMDI: 0.17 sec). The coefficient of variance (CV) of emitted doses generated from SMI and pMDI was 1.83% and 6.84%, and the residual drug quantities from both inhalers were about 20%. The aerosol size distribution generated from the SMI showed a bimodal distribution with a coarse particle mode around 3 µm and a fine particle mode of less than 1 µm. We infer that these two size modes may represent main droplets and satellite droplets generated from the process of the breakage of two converging liquid jet. In addition, the MMAD (Mass Median Aerodynamic Diameter) of the SMI was smaller than that of the pMDI (SMI: 2.32 µm; pMDI: 3.32 µm), and the mass fraction of particle size < 2 µm of the SMI and the pMDI were 48.0% and 27.1% respectively. However, there were no significant differences in the FPF (Fine Particle Fraction, particle size < 5 µm) between both inhalers. Finally, whichever inhalation aids (spacer or VHC) were used, the MMAD of both inhalers decreased.


Exploring the design space for dry powder inhalers, a case study with two types of capsule devices
John Swarbrick

In the current Quality by Design paradigm, the development of a pharmaceutical product requires a thorough understanding of the design space to enable the built in of quality in the product. The design space of a product is defined by critical process parameters and critical material attributes. In carrier based DPI devices a number of attributes have been evaluated. It has been found that type and amount of fine particles of the carrier can be regarded as critical attributes. Here we will focus on the development of a design space based on type and amount of fines and relating that to functionality of the inhaler. In one aspect, functionality can be defined as the ability to fill devices with the formulation. This can be described by the flow function of the powder measured by for instance the Hausner Ratio (HR). Depending on type of device and type of fill station, either more cohesive powders (HR>1.30) or more good flowing powder (HR<1.20) is required. Another aspect of functionality of inhalers can be defined as the ability to deliver the drug to the lungs. The fine particle fraction (FPF), as measured in a suitable cascade impactor like an NGI, is used to describe this. Generic development of a drug product requires the FPF to be within tight registrated specifications. Here we will show a case study of two capsule based devices (Handihaler® and Cyclohaler®) that were formulated with a 2% budesonide in lactose (Lactohale®, DFE Pharma). The carrier consisted of a coarse grade of lactose complemented with different types of fine graded lactose. This resulted in a development space with type of fine grade lactose (d50 of the fine grade varying from 5-15 µm) and amount of this fine grade (2.5-20 wt%) as factors and FPF and HR as the responses. Targets were set on FPF and HR and the design space to meet these both targets were established for both devices. To meet the same criteria in both devices, each device requires its own design space. By utilizing the right type and amount of lactose, functionality can be designed. The understanding of the design space gives control on the functionality and thereby control on quality.


The Use of Spray freeze drying technology to produce nucleicacid formulation for pulmonary delivery
Wanling Liang

Nucleic acid therapeutics have potential for the treatment of various lung diseases including respiratory infections, asthma and chronic obstructive pulmonary disease. Dry powder formulation offers several advantages over liquid aerosol in formulating macromolecules such as better stability and compatibility. Spray freeze drying (SFD) is a drying process that can be used to produce inhaled nucleic acid powder. It involves the atomization of liquid into fine droplets which are instantaneously frozen in a cryogenic liquid, followed by the freeze drying of samples which are sublimed at low temperature and pressure to form porous particles. In this study, SFD technology was investigated to produce inhaled formulation of nucleic acids, with herring sperm DNA (hsDNA) used as a model nucleic acid and mannitol used as a bulking excipient. Different SFD formulations were prepared by varying the solute concentration (1 – 7.5% w/v) and hsDNA concentration (0.25 – 2% w/w) in the feed solution. The particle size distribution and the morphology of the spray freeze dried powders were examined by laser diffraction and scanning electron microscope respectively. The aerodynamic properties of the powder were assessed by next generation impactor (NGI). The fine particle fraction (FPF), which is defined as the fraction of powder exhibited aerodynamic diameter below 5 m, was calculated to determine the optimal formulation for inhalation. The morphology study revealed that particles produced by SFD were overall spherical in shape. At low solute concentration (below 5% w/v), the powders were highly porous and fragmentation could be observed. When the solute concentration was kept at 5% w/v, varying hsDNA concentration did not have a major effect on the particle size distribution, with the median diameter (measured by laser diffraction) around 10 to 15 m. The NGI study showed that the SFD formulations had a FPF between 20 to 30%. As the hsDNA concentration increased from 0.25 to 2% w/w, the FPF increased, and the formulation containing 2% hsDNA w/w exhibited a significantly higher FPF than the others. Overall, this study demonstrated that inhalable nucleic acids dry powder formulations can be successfully produced by SFD. Further studies will be carried out to investigate whether the increase of nucleic acids content could enhance the FPF, and formulations containing different types of nucleic acids such as small interfering RNA (siRNA) and microRNA will be explored.


Derivate of Hyaluronic Acid and its potential use for respiratory drug delivery for treatment of inflammatory lung diseases
Michele Pozzoli

Sodium hyaluronate (NaHY) has gained attention for inhalation due to its therapeutic potential in inflammatory lung disorders, in particular for asthma, emphysema and chronic obstructive pulmonary diseases and its activity as a biocompatible and biodegradable drug carrier. Purpose: The aim of this study was to develop an inhaled formulation using a novel derivate of NaHY, in combination with an antioxidant drug (Sodium Ascorbyl Phosphate, NaP) as potential synergic anti-inflammatory and antioxidant therapy. The formulation was evaluated for its in vitro efficacy to reduce inflammation on Calu-3 epithelial lung cells. Material & Methods: Microspheres were produced by spray-driying using a mini spray-dryer B-290. Briefly, NaHY derivate and NaP were dissolved in water at a concentration of 0.15 (w/w %) and 0.45 (w/w %), respectively, and the solution was spray-dried at the following process parameters: inlet temperature 150 °C, solution feed rate of 3.0 mL/min and nozzle diameter of 1.4 mm. Under these conditions, an outlet temperature ranging from 78 to 82 °C was observed. A dehumidifier B-296 was used to control the air humidity of the system. The particle size of the obtained microspheres was measured using laser diffraction (Mastersizer, Malvern Instruments). The biological effect of the formulation was tested on Calu-3 cells. Inflammation was induced with 10 ng/mL Lipopolysaccharides (LPS) 24 h after cell seeding. Subsequently, cells were treated with the combination of NaHY and NAP therapy and compared to NaHY alone and NAP alone as controls. Supernatants were collected and IL-6 cytokine was quantified as an inflammatory marker using commercially available ELISA kit (BD OptEia, BD Biosciences). Results & Discussion: The microspheres obtained showed suitable aerodynamic sizes for delivery to the lung with a Dv10, 50 and 90 of 1.2 ± 0.1 µm, 3.4 ± 0.3 µm and 17.9 ± 7.6 µm, respectively. It was found that LPS-induced Calu-3 cells produced 1165.7 ± 202.0 pg/mL of IL-6, compared to a basal level (no stimuli) of 270.7 ± 18.7 pg/mL. All treatments showed the ability to reduce IL-6 level, compared to untreated LPS induced cells. More specifically, NaHY decreased IL-6 levels to 655.3 ±135.0 pg/mL, and NaP to 868.1 ± 262.1 pg/mL, respectively. Furthermore, a significant improvement of the anti-inflammatory activity was obtained with the combination of NaP and NaHY (IL-6 concentration 431.3 ± 61.7 pg/mL). Conclusion: The innovative co-spray dried NaHY and NAP formulation appears to be a promising inhalable dry powder formulation for the treatment of inflammatory lung diseases


Development and characterization of a dry powder phosphodiesterase 4 inhibitor formulation for the treatment of chronic obstructive pulmonary disease
Mohammad A. M. Momin

Background: Roflumilast, a phosphodiesterase 4 inhibitor, is currently used orally to treat chronic obstructive pulmonary disease (COPD). Gastrointestinal disturbance and weight loss are the common dose-dependent side effects of orally administered roflumilast. Pulmonary administration of roflumilast can reduce the dose and thereby potentially reduce its side effects. The purpose of this study was to develop an inhalable roflumilast dry powder by co-spray-drying with L-leucine and trehalose.

Methods: In a systematically designed experiment varying the spray-drying conditions, nine roflumilast powders were produced by co-spray-drying roflumilast with L-leucine and trehalose using a Buchi B-290 Mini Spray-Dryer. Particle sizes of the powders were measured by laser diffraction. The optimized powder formulation was investigated for morphology, crystallinity, thermal analysis and water content by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively. The in vitro drug deposition of the powders was evaluated using a twin-stage impinger (TSI). The aerosolization efficiency of the optimized powder was evaluated by a Next Generation Impactor (NGI) using an aerolizer device at 100 L/min. Cytotoxicity study (MTT assay) of roflumilast was conducted using alveolar epithelial cell line (a549 cells).

Results: An inhalable roflumilast powder of homogenous particle size (D50: 4.3 µm, span < 2.0) was successfully developed by co-spray-drying with L-leucine and trehalose using optimized spray-drying conditions. The spray-drying yield was about 60%. The developed particles were disc shaped, amorphous in nature and had low moisture content (1.6 ± 0.3% w/w) with a Carr’s index value < 30%. The optimized powders had high emitted dose (%ED > 88.0) and fine particle fraction (%FPF > 52.0). Roflumilast was found to be safe for A549 cells at a concentration up to 8mg/mL.

Conclusion: An inhalable roflumilast powder formulation with high aerosolization capacity has been developed by co-spray drying with L-leucine and trehalose. Although further in vivo tests are necessary, the powder is a promising candidate for the effective treatment of COPD with reduced side effects.


Inhalable powder formulations for treating latent and multidrug-resistant tuberculosis: Formulation and in vitro characterization
Claire Fan

Tuberculosis (TB) is a leading cause of death, and latent and multidrug- resistant (MDR) tuberculosis has raised a significant concern worldwide. The current TB treatment by oral and parenteral route of administration is long and complex, along with various unwanted side effects. Pulmonary administration via dry powder inhalers has various advantages over oral and parenteral administration due to its direct drug delivery to the site of action, lung, and minimization of systemic side effects. A novel drug, PA-824, has shown a powerful bactericidal effect against both active and latent forms of Mycobacterium tuberculosis (MTB), as well as MDR-TB. Moreover, PA-824 gives synergistic effect when combined with other anti-TB drugs. The aim of this study was to develop and optimize a dry powder formulation containing PA-824 and pyrazinamide with a good aerosolization ability for inhalation. Methods: Dry powder formulations of PA-824 in combination with pyrazinamide and L-leucine were produced using a BUCHI B-290 Mini Spray Dryer. The spray dried powders were characterized for particle size, morphology and solid states. In vitro lung deposition behaviour was determined using a Next Generation Impactor (NGI). Stability of the formulation was tested after one and three-month storage under desiccator at room temperature. Cell cytotoxicity was tested by cell Titer 96® Non–Radioactive cell proliferation assay (MTT) using alveolar basal epithelium cell line A549. Cells were treated for 72 hours with increasing drug concentrations 1-150µg/ml. Results: Dry powders of PA-824 in combination with pyrazinamide and L-leucine for inhalation with improved aerodynamic characteristics were developed. The yield of the spray dried formulations was 50%, and the powders were uniform in drug content (>90%). The particles were hollow spherical with dents. The particle size of the spray- dried powder was 2.0 ±0.6μm with a size range from 0.6-4.1μm indicating the powder was suitable for the deep lung delivery. Solid state characterization confirmed the presence of PA-824 in amorphous form after spray drying. However, pyrazinamide remained crystalline in a different polymorphic form after spray drying. In vitro aerosolization results showed around 90% of emitted dose with 65.5±0.1% fine particle fraction indicating good aerosolization suitable for the deep lung delivery. The developed powder showed a good stability with similar aerosolization behavior even after three months storage at room temperature under desiccator conditions. The dose response cytotoxicity results showed pyrazinamide was non toxic in A549 cell line. Although the cell viability decreased with increasing concentration of PA-824, >70% cells were alive at a concentration of 50 µg/ml. Conclusions: A dry powder formulation combining PA-824 with pyrazinamide was successfully developed which showed good aerosolization performance and stability, and generally safe to alveolar cell lines. This formulation can have a greater potential to treat tuberculosis.