The purpose of this research was to evaluate the capability and performance of the University of South Florida’s (USF) Human Exposure Chamber (HEC) using aerosols in the thoracic range. The goals of this research were two-fold: to obtain an average particle size of 10 µm (thoracic-size range) inside the chamber during dust production and to test for evenness of dust concentration within the chamber. The USF HEC can be used for studies using gases and/or particulates. The chamber measurements are 4.16 ft x 2.67 ft x 6.75 ft, for a total volume of 75 ft3 or 2.13 m3. This research has public health significance since outdoor air pollution is found most commonly in the thoracic size range; future studies with the HEC could focus on the impact of outdoor air pollution on human subjects under various exposure conditions, and various particle size ranges. Soda lime glass beads were used in this study due to their uniformity in shape and size. A Wright Dust Feeder (WDF) was used to generate the glass beads aerosol in the chamber. Nitrogen gas and HEPA-filtered fresh air were used to transport the aerosol through the system and into the chamber. A total of nine different chamber configurations were made in order to increase the average particle size closer to the goal of 10 µm. Chamber reconfiguration provided statistically significant effect on increasing particle size with the exception of two intermediate settings. It was concluded that aerosol distribution within the chamber was even during operation of the chamber, and modification steps utilized in the study provided size distribution within +/- 6% of the target particle size.

The diploma thesis is devoted to study potential risks for living organisms resulting from inhalation of nanoparticles of chosen heavy metals. The main aim of this work is the investigation of organs from experimental white mice after their guided inhalation of lead nanoparticles. The samples of liver and lungs from these animals are taken in time periods during the inhalation experiments and processed by specific methods for their evaluation. After pressurized microwave assisted decomposition of selected samples of mice organs in high purity concentrated nitric acid the content of lead is determined by atomic absorption spectrometry with electrothermal atomization. Furthermore, the changes are monitored using the microscopy of histological slides stained with hematoxylin-eosin. The results of both approaches are evaluated and compared within the frame of this work.

Le cancer du poumon est l’un des cancers les plus fréquents dans le monde et reste le plus meurtrier actuellement en terme d’incidence absolue. Les traitements employés chez les patients atteints d’un cancer du poumon consistent en une combinaison de chirurgie, de radiothérapie et de chimiothérapie. Alors qu’il y a quelques années, les guidelines de traitement étaient principalement basées sur le stade clinique de la maladie, le développement de nouvelles thérapies a mené à une classification plus appropriée des cancers du poumon. Cette nouvelle classification se base, en plus du stade clinique de la maladie, sur l’expression de différents biomarqueurs exprimés chez des sous-populations bien définies de patients. Ces biomarqueurs sont par exemple la mutation d’un gène ou l’expression d’une protéine. Au cours de ces dix dernières années, la recherche a été très active dans ce domaine avec l’arrivée de nouveaux traitements plus spécifiques pour ces sous-populations de patients. Des exemples concrets de ces nouvelles thérapies sont les chimiothérapies dites ciblées et l’immunothérapie. L’arrivée de tels traitements a parmi d’augmenter significativement le pronostic de la maladie et également de réduire considérablement les graves effets secondaires des chimiothérapies conventionnelles. Toutefois, le bénéfice en termes de survie reste modéré. Le taux de survie des patients à cinq ans est actuellement de 15%. Il y a donc toujours un besoin urgent de mettre au point de nouvelles stratégie de traitement.La chimiothérapie inhalée constitue une perspective de traitement adjuvant du cancer du poumon très intéressante, comparée à la chimiothérapie conventionnelle. En effet, elle permettrait d’administrer des doses d’anticancéreux plus importantes directement au niveau du site tumoral tout en limitant l’exposition systémique du médicament dans l’organisme, et donc, les toxicités importantes s’y rapportant. Toutefois, aucun médicament suivant cette approche n’est actuellement disponible sur le marché et ce, malgré quelques études cliniques de Phase I/II. Cela peut principalement s’expliquer par (i) l’incapacité d’administrer des doses inhalées efficaces d’agent anticancéreux avec les dispositifs d’inhalation utilisés (les nébuliseurs), (ii) les inquiétudes quant à une possible augmentation des toxicités pulmonaires des agents anticancéreux administrés par inhalation, (iii) les moyens devant être mis en place afin d’assurer la non-contamination de l’environnement et du personnel soignant lors d’une séance d’inhalation. Basée sur de nouvelles technologies pharmaceutiques (l’inhalation sous forme de poudre sèche, les nanomédecines, les thérapies ciblées, etc.) et sur une meilleure connaissance de la biologie des cancers, la stratégie scientifique que nous proposons pourrait permettre d’apporter une solution aux problématiques précitées. Ce travail décrit le développement de nouvelles formulations de poudre sèche pour inhalation (« dry powder for inhalation », DPI) à base de nanovecteurs ciblés contre le récepteur au folate (« folate receptor », FR) pour le traitement sélectif de cancers du poumon FR-positifs. Ces formulations permettraient le ciblage (i) du site tumoral par l’utilisation de l’administration pulmonaire et (ii) spécifique des cellules cancéreuses du poumon par les nanovecteurs ciblés. Trois parties constituent ce travail.Dans la première partie, deux nouveaux excipients folatés (c.à.d. sur lesquels ont été greffés des groupements folates) ont été synthétisés en trois étapes principales par une méthode de synthèse faisant appel à des dérivés de carbodiimide. Ces excipients comportent trois types de composants majeures relatifs à leur fonction :un ligand, le groupement folate, pour le ciblage des FRs ;un composé de charge, un polysaccharide, capable d’interagir avec l’agent anticancéreux ou une structure contenant celui-ci ;et un spacer, le poly(éthylène glycol), afin d’assurer une bonne flexibilité du folate et ainsi permettre une bonne interaction avec le FR. Ces nouveaux excipients folatés ont été caractérisés par RMN du proton, par spectrométrie de masse et par analyse thermique. L’excipient F-PEG-HMD (« folate-poly(ethylene glycol)-hydrophobically-modified dextran ») était capable de former des micelles caractérisées par une distribution de taille particulaire bimodale dans l’eau, avec un diamètre moyen d’environ 80 nm. F-PEG-HMD était caractérisé par une concentration micellaire critique de 4 x 10-7 M. L’excipient F-PEG-HTCC (« Folate-poly(ethylene glycol)-(N-[(2-hydroxy- 3-trimethylammonium)propyl] chitosan ») présentait des charges positives permettant de se solubiliser en milieu aqueux, indépendamment du pH.Dans la deuxième partie du travail, des formulations DPI ont été développées à base de l’agent anticancéreux témozolomide (TMZ). Celui-ci a été choisi comme premier modèle de principe actif pour son mécanisme d’action particulier qui lui confère une activité dans les cancers apopto-résistants, comme c’est le cas de beaucoup de cancers du poumon. De plus, l’administration d’une formulation de TMZ sous forme de nanovecteur permettrait de considérablement augmenter son activité en augmentant, par exemple, sa stabilité in vivo, ou encore son incorporation intracellulaire spécifique dans les cellules cancéreuses. Toutefois, le TMZ est caractérisé par des propriétés physicochimiques ne permettant que très difficilement son encapsulation dans des nanovecteurs. Le TMZ est une petite molécule, faiblement soluble dans l’eau sans toutefois être lipophile. Comme type de nanovecteur, les micelles polymériques pourraient présenter un bon profil pour encapsuler le TMZ. Des micelles composées de F-PEG-HMD et de TMZ ont été préparées par solubilisation de ces deux composés en présence. La solubilité dans l’eau du TMZ a pu ainsi être doublée en présence de F-PEG-HMD, ce qui pourrait mener à des concentrations de TMZ augmentées au sein du site tumoral. Les micelles polymériques présentaient un diamètre moyen de 50-60 nm, en fonction de la concentration en F-PEG-HMD utilisée. Les formulations DPI ont été préparées par spray-drying des micelles en présence de mannitol et de leucine. Le TMZ est resté stable durant l’étape de spray-drying, ainsi confirmé par des propriétés antiprolifératives in vitro des formulations DPI semblables à une solution de TMZ. Deux des formulations DPI développées présentaient de bonnes propriétés aérodynamiques, avec des fractions en particule fine jusqu’à 50%, et étaient capable de libérer les micelles polymériques rapidement en milieu aqueux. Toutefois, les taux d’encapsulation obtenus étaient relativement bas (inférieurs à 10%). Le travail s’est donc poursuivi avec un autre agent anticancéreux, le paclitaxel.Dans la troisième partie du travail, des formulations DPI à base de nanovecteurs chargés en paclitaxel (PTX). Le PTX a été choisi comme deuxième modèle d’agent anticancéreux car il s’agit d’une des molécules les plus couramment utilisées dans le traitement du cancer du poumon, et ce malgré les graves effets secondaires systémiques engendrés par l’administration intraveineuse de ce médicament. L’utilisation de la voie pulmonaire pourrait permettre d’optimiser les traitements à base de PTX, et ainsi, la qualité de vie des patients (réductions conséquentes des graves effets secondaires systémiques et meilleure réponse thérapeutique). Deux types de nanovecteurs ont été préparés avec des taux d’encapsulation en PTX d’approximativement 100%. Des micelles polymériques à base de F-PEG-HMD et de PTX ont été préparées par une méthode de dialyse avec un diamètre moyen de 50 nm et un potentiel zêta d’environ -4 mV dans le PBS. Des nanoparticules lipidiques solides (« solid lipid nanoparticle », SLN) chargées en PTX ont été préparées par une méthode de nanoprécipitation et les SLNs ont ensuite été enrobées par F-PEG-HTCC. La présence de l’enrobage a été confirmée par la taille et la charge des particules (diamètre moyen de 160 nm à 230 nm et potentiel zêta de -20 mV à + 30 mV, avant et après enrobage, respectivement). Les nanovecteurs étaient capables d’être incorporés, in vitro, dans les cellules HeLa et M109-HiFR, deux lignées de cellules cancéreuses exprimant le FR, et in vivo, après administration par inhalation sur un modèle orthotopique de cancer pulmonaire murin Ce modèle, le modèle M109, a été développé dans le cadre de ce travail à partir de la lignée M109-HiFR. Après administration par inhalation, les SLNs restaient enrobées dans les tissus pulmonaires et tumoraux. Les nanovecteurs ont montré une activité antiproliférative in vitro sur les deux lignées précitées. De plus, cette activité était significativement plus grande avec les SLNs enrobées chargées en PTX qu’avec la formulation commerciale contenant le paclitaxel, le Taxol®, avec des concentrations inhibitrices médianes de 60 et 340 nM, respectivement. L’activité anti-cancéreuse in vivo des SLNs enrobées, qui présentaient un meilleur profil que les micelles polymériques pour être étudiées in vivo (plus haute teneur en PTX, plus grande activité antiproliférative, et meilleure profil de libération du PTX in vitro), a été évaluée sur le modèle M109. Les SLNs enrobées, administrées par inhalation, seules ou en association avec le Taxol par intraveineuse, ont été comparées au Taxol®, administré par inhalation, par intraveineuse ou les deux, à la même dose de PTX totale. Les traitements à base des SLNs enrobées, en particulier en association avec le Taxol® en intraveineuse, ont menés un allongement significatif de la survie des souris M109, par rapport au Taxol en intraveineuse seul (survie médiane de 38 et 27 jours, respectivement). De plus, la mort de la dernière souris M109 a été observé au jour 61 pour le traitement SLN/Taxol en association, comparé au jour 33 pour le Taxol en intraveineuse, seul, à la même dose totale en PTX (10-8-8-8 mg/kg), et au jour 29 pour le contrôle négatif (c.à.d. les souris n’ayant pas reçu de traitement). Des études supplémentaires sont toutefois requises pour conclure une potentielle augmentation de l’activité anticancéreuse des SLNs inhalées par rapport au Taxol®. En effet, les doses de PTX en inhalation étaient trop grandes pour le modèle M109 menant à la mort d’une partie non négligeable des souris M109. Nous pouvons toutefois conclure que le traitement à base des SLNs inhalées en association avec le Taxol® en intraveineuse semble prometteur pour la suite du projet. Des formulations DPI ont ensuite été produites à partir des nanovecteurs chargés en PTX par spray-drying. Les formulations obtenues présentaient une large déposition in vitro dans les poumons, avec des fractions en particule fine allant jusqu’à 50% et de bonnes propriétés de libération des nanovecteurs en milieu aqueux. Quel que soit le principe actif ou le nanovecteur utilisé, les formulations DPI développées ont montré une large déposition pulmonaire in vitro dans les voies aériennes inférieures, où les adénocarcinomes pulmonaires sont le plus souvent trouvés. De plus, les formulations ne contenant que les excipients étaient bien tolérées in vivo après inhalation chez la souris saine. Cela a été vérifié par analyse des fluides bronchoalvéolaires en termes de concentration totale en protéine, de population de cellules, et de concentration en cytokines IL-1β, IL-6, and TNF-α. Ce travail montre dès lors également que les formulations DPI pourraient constituer un système de délivrance de médicament intéressant pour amener des nanovecteurs dans le tractus respiratoire où la tumeur réside. Toutefois, alors que de nombreuses caractéristiques intéressantes des formulations ont été démontrées (la tolérance des excipients, les profils de libération du PTX obtenus, l’incorporation intracellulaire des nanovecteur ainsi que leur bonne distribution dans du tissu tumoral in vivo et leur activité anticancéreuse, etc.), l’implication des FRs pour expliquer ces caractéristiques n’a pas pu être établie clairement. / Lung cancer is one of the most frequent cancers in the world, and remains the most deadly. Lung cancer therapy involves the combination of surgery, radiotherapy and chemotherapy. Whereas the treatment guidelines used to be related mainly to the stage of the disease, more recent treatments have introduced the concept of treating lung cancers according not only to the stage, but also to the specific characteristics of the tumors, i.e. a gene mutation, expression of a protein, etc. In the last decade, scientific and clinical research has been very active in this field, with recurrent introduction of new treatments, including new chemotherapies (e.g. targeted chemotherapies and immunotherapies). Many of these new treatments certainly induce better therapeutic responses and a sharp reduction in the adverse effects of conventional chemotherapies for well-defined subpopulations of patients. However, the benefit in terms of survival rates is only moderate. The five-year survival rate is currently ~15%. There is therefore no doubt that new treatment approaches and strategies are needed. One interesting approach is aerosolized chemotherapy. The pulmonary delivery of anti-cancer drugs could potentially be an interesting alternative to conventional adjuvant chemotherapy in lung cancer treatment, for many reasons. Among them, it could enhance the therapeutic ratio significantly by decreasing systemic severe toxicities and increasing anti-tumour efficacy. However, despite interesting clinical trial reports, all the strategies describing an aerosolized anti-cancer treatment have failed to bring new medicine on the market so far. The failures have been related mainly to (i) the inability to deliver proper and efficient drug doses in the lungs with the inhalation devices used in clinical trials (i.e. nebulizers), (ii) concerns about potential increase in lung toxicities engendered by these anti-cancer drug-based aerosols, and (iii) the requirement for adapted facilities to perform the inhalation procedure safely. Based on new pharmaceutical technologies (i.e. dry powder for inhalation (DPI) technology, nanomedicine, drug targeting, etc.) and on a better knowledge of cancer biology, a plausible and feasible answer to the aforementioned causes of failure was proposed. In this work, new nanomedicine-based DPI formulations were designed and developed for proposal as adjuvant chemotherapy for lung cancer treatment, especially for folate receptor (FR)-positive adenocarcinomas. These formulations would potentiate chemotherapy by means of a dual-targeting approach, i.e. the targeting of (i) lung tumor site(s) with pulmonary delivery and (ii) lung cancer cells with FR-targeted nanocarriers. To set up this approach, the work included three parts.In the first part, two new folate-grafted excipients were synthesized using carbodiimide-mediated chemistry in three main steps. These excipients consisted of three main components with a defined function: a ligand bringing selectivity, i.e. folate groups; a loading compound able to interact non-covalently with the anti-cancer drug or a drug delivery system, i.e. polysaccharides; and a spacer ensuring good flexibility of the ligand to allow its binding to the target, i.e. poly(ethylene glycol). The excipients were characterized by 1H-NMR, mass spectrometry and thermal analysis. Folate-polyethylene glycol-hydrophobically-modified dextran (F-PEG-HMD), a new folate-grafted self-assembling copolymer, presented a critical micellar concentration in water of 4 x 10-7 M. F-PEG-HMD micelles were characterized by a trimodal particle size distribution with a Z-average diameter of about 80 nm in water. Folate-polyethylene glycol-(N-[(2-hydroxy- 3-trimethylammonium)propyl] chitosan) (F-PEG-HTCC) presented positive charges and was easily dissolved in water, regardless of the pH.In the second part, dry powders were developed with the anti-cancer drug temozolomide (TMZ). TMZ was chosen as the first anti-cancer drug model due to its interesting anti-cancer activity in poor prognosis, apopto-resistant cancers, as is the case for many lung cancers. In addition, TMZ delivery via a nanocarrier might present many advantages such as prolonged lifetime and specific improved intracellular delivery into cancer cells. However, TMZ is characterized by poor properties for encapsulation into nanocarriers. It presents poor water solubility and low lipophilicity. Because of these properties, polymeric micelles presented the best profile for entrapping TMZ. TMZ-loaded F-PEG-HMD micelles were prepared by co-dissolution of TMZ and F-PEG-HMD. TMZ solubility in water was increased in the presence of F-PEG-HMD (a two-fold increase in molar solubility) which could potentially lead to increased local concentrations in the tumor site. The TMZ-loaded F-PEG-HMD micelles were characterized by Z-average diameters in the range of 50-60 nm, depending on the F-PEG-HMD concentration used. The micelles were spray dried to produce dry powders. TMZ remained stable during all the formulation steps, confirmed by similar in vitro anti-proliferative properties for the DPI formulations and a TMZ solution. Two of the developed DPI formulations were characterized by good aerodynamic properties (with a fine particle fraction of up to 50%) and were able to release the F-PEG-HMD micelles quickly in aqueous media. However, as presumed, poor entrapment efficiency values were obtained (less than 10%). A second anti-cancer compound was therefore chosen to pursue in the study, the lipophilic paclitaxel.In the third part, nanocarrier-loaded dry powders were developed with the poorly water-soluble anti-cancer drug paclitaxel (PTX) and the new folate-grafted excipients. PTX was chosen as a model drug because it is an effective anti-cancer drug currently used in lung cancer therapy and it causes severe systemic toxicities when delivered by the conventional intravenous route. Pulmonary delivery of PTX might therefore optimize treatment efficacy and/or quality of life in lung cancer patients. Two types of PTX-loaded nanocarrier were prepared with an encapsulation efficiency of approximatively 100%. PTX-loaded F-PEG-HMD micelles were prepared by a dialysis method. These had a Z-average diameter of about 50 nm and a zeta potential of about -4 mV in PBS. F-PEG-HTCC-coated solid lipid nanoparticles (SLNs) loaded with PTX were prepared in two main steps. PTX-loaded SLNs were first prepared using a nanoprecipitation method and the SLNs were then coated with F-PEG-HTCC. Efficient coating was confirmed by particle size and zeta potential (Z-average diameter of 160 nm to 230 nm and zeta potential of -20 mV to +30 mV before and after F-PEG-HTCC coating, respectively). The nanocarriers were able to enter HeLa and M109-HiFR, two FR-expressing cancer cell lines, in vitro, and in vivo after administration by inhalation to orthotopic M109-HiFR lung tumor grafted mice. This orthotopic model, i.e. the M109 model, was developed in the study. The SLNs remained coated with F-PEG-HTCC in lung tissues and tumors after inhalation. The PTX contained in the nanocarriers remained active against HeLa and M109-HiFR in vitro, as observed by means of the colorimetric MTT assays. Moreover, PTX-loaded SLNs were characterized by significantly higher anti-proliferative properties than Taxol®, with half-maximal inhibitory concentrations of 60 and 340 nM, respectively. Afterwards, the in vivo anti-cancer activity of the coated SLNs, which led to better profile than the polymeric micelles to be studied in vivo (i.e. higher PTX loading, higher anti-proliferative properties, and better release profile of PTX in vitro), was evaluated using the M109 model. The coated SLNs, administered by inhalation, alone or combined with intravenous Taxol®, were compared with Taxol®, administered by inhalation, IV or both, at the same PTX-relative doses. Interestingly, we observed much longer survivals for the SLN inhaled treatments, especially when combined with intravenous Taxol®, than for intravenous Taxol alone (median survivals of 38 and 27 days, respectively). Moreover, the last tumor-bearing mouse death occurred at day 61 for the SLN combined therapy, compared with day 33 for the intravenous therapy alone, at the same total PTX-relative dose (i.e. 10-8-8-8 mg/kg), and with day 29 for negative control (i.e. non-treated mice). However, further evaluations are needed to conclude that there is any improvement in terms of therapeutic response compared with intravenous Taxol®. Indeed, bias related to the fact that the aerosolized PTX doses were too high was included in the survival rate analysis and was revealed by unacceptable treatment-related deaths. Nevertheless, the combination of aerosolized, loaded SLNs and intravenous Taxol seemed to be an interesting strategy of treatment to follow. Dry powders embedding the PTX-loaded nanocarriers were developed by spray-drying. In vitro, good deposition profiles were obtained, with a fine particle fraction of up to 50% and good ability to re-disperse the nanocarriers in aqueous media.Whatever the drug or the nanocarrier adopted, the developed DPI formulations showed wide in vitro pulmonary deposition in the lower respiratory tract, where adenocarcinomas are more often found. Moreover, nanocarrier-based dry powders without drugs were well-tolerated in vivo, as assessed in healthy mice by determination of total protein content, cell count, and cytokine IL-1β, IL-6, and TNF-α concentration in bronchoalveolar lavage fluids. The present work therefore also shows that dry powders for inhalation could constitute an interesting drug delivery system able to release nanocarriers in the respiratory tract where the tumor is growing and spreading. However, in contrast to the undeniable improvements in terms of drug delivery system (e.g. safety of the excipients, drug release profile, the cell binding and uptake of the nanocarriers and their distribution into tumor in vivo, anti-cancer activity), no substantial effect linked to an implication of the FRs was observed to explain the aforesaid improvements. / Doctorat en Sciences biomédicales et pharmaceutiques (Pharmacie) / info:eu-repo/semantics/nonPublished

Among the different pulmonary fungal infections, aspergillosis, and in particular invasive pulmonary aspergillosis (IPA), are becoming the most worrying diseases in immunocompromised patients. This is due to their high incidence and mortality. Indeed, invasive aspergillosis manifests as invasive pulmonary disease accounting for 50/60% of all cases, with a mortality of 50-90% in severely immunocompromised patients. Triazoles act by inhibiting 14-α demethylase, a fungal cytochrome P450 enzyme implicated in the synthesis of ergosterol, an essential constituent of fungal cell walls. Moreover, they interact with the same cytochrome present in large quantities in the human liver, inducing possible drug-drug interactions in IPA patients. Consequently, interactions resulting from inhibitors, inductors, or substrates of cytochromes can modify the plasmatic concentrations of triazoles or other drugs administered concomitantly. To overcome these important issues, pulmonary delivery of triazoles could be an interesting alternative to conventional routes.The aim of this work was to develop triazole-based dry powders for inhalation able to be deposited adequately in the lungs, with a release of drug and a lung retention that can optimize its pharmacological action. This work focused on two active pharmaceutical ingredients (API): itraconazole (ITZ), for which improved solubility was needed, and voriconazole (VCZ), for which slow release was required.Concerning ITZ, solid dispersions for inhalation (SDIs) comprising ITZ and mannitol were previously developed in our laboratory. The selected SDI showed interesting results in terms of improved dissolution and lung retention in vivo in mice during a pharmacokinetic study. Therefore, this SDI was tested in a murine preclinical model of IPA and showed promising results in terms of prophylaxis efficacy. One aim of this work was to continue the pharmaceutical development of this promising SDI by making a scaling-up study. These methods were intended to improve the SDI’s ecological footprint and productivity by increasing the production yield and decreasing the amount of solvents and time used in its manufacture. During the first step of this study, the obtained SDI showed interesting results obtaining similar powder characteristics (i.e. amorphous content, aerodynamic performance, and dissolution profiles) from concentrated solutions using a laboratory-scale spray-dryer B-290 (Büchi, Switzerland) before using a pilot-scale spray-dryer (GEA Niro, Denmark). Then, the upscaling was performed on the pilot spray-dryer allowing the production of SDIs with increased productivity (yield and process duration). These SDIs had similar powder characteristics than the optimized lab-scale SDIs. During the second part of this work we developed VCZ based dry powder for inhalation. The aim was to slow down the release of this highly permeable and very slightly soluble API and to prolong its lung residence. To this end, various lipidic excipients were chosen. The selection took into account the potential good pulmonary tolerance of the lipids and their hydrophobicity to evaluate their ability to slow down the VCZ release (FPFs 20-25%, slowed release up to 24h, burst effect of ± 58% of VCZ dissolved within 30min). Immediate-release SDIs were also developed to have a comparator reference for the pharmacokinetic and efficacy studies (FPFs of 40%).Then, a pharmacokinetic study in mice was performed following the pulmonary administration of one immediate-release and two sustained-release SDIs (with or without PEG excipient). With an 80-fold higher pulmonary exposure over 24 hours, the slow-release SDIs presented a real interest compared to the immediate-release SDI. Moreover, in accordance with these results, VCZ plasma exposure following the administration of the SDI with PL90-H was more than 1.5-fold higher than its pulmonary exposure (AUC0-24 of 8.70 µg.h/g in the lungs and 14.70 µg.h/mL in the plasma). The slow-release formulations presented plasma exposures at least 15 times lower than their pulmonary exposures (AUC0-24 in lung of 741.40 and 686.85 µg.h/g vs plasmatic AUC0-24 of 37.44 and 42.81 µg.h.mL, respectively with and without PEG excipient). Moreover, the presence of PEG excipient did not influence the residence time and the exposure of the VCZ within the lungs. Finally, the sustained-release SDIs administration by inhalation led to VCZ lung and plasma concentrations higher than the minimal inhibitory concentration (MIC) of VCZ against Aspergillus fumigatus (1 μg/mL) over 24 h. Finally, a murine model of IPA was developed in our lab. The immunosuppression model was fixed and performed by the intraperitoneal (IP) injection of corticosteroids to induce a neutropenia state. Then, different doses of spores (from 1.10^4 to 5.10^6 spores) were inoculated to the neutropenic mice via an endotracheal instillation and the survival rate of each group was observed. Unfortunately, the survival rate resulting from the different infections were not reproducible. Therefore, these models were not suitable to conduct the efficacy study. This underlined the link between the immunosuppressive model and the infection. Indeed, the IPA murine model should be developed according to the immune state of the animal, the Aspergillus conidia species and its concentration to be used. / Doctorat en Sciences biomédicales et pharmaceutiques (Pharmacie) / info:eu-repo/semantics/nonPublished

L’asthme est un désordre respiratoire caractérisé par une prévalence élevée dans laquelle une proportion des individus ne répondent pas bien aux traitements actuels. Afin de développer des traitements plus efficaces, il est nécessaire de mieux comprendre les mécanismes physiopathologiques de l’asthme. Le muscle lisse des voies aériennes joue un rôle central dans ce désordre respiratoire puisque son activation intense et sa contraction excessive contribuent à l’obstruction des voies aériennes donnant lieu aux symptômes de l’asthme. Les deux projets présentés dans ce mémoire étudient les effets de l’administration répétée d’un activateur du muscle lisse des voies aériennes, soit la métacholine, chez la souris. L’hypothèse du premier projet stipule que des bronchoconstrictions induites par la métacholine favoriseraient le développement de changements structuraux dans les parois aériennes des sujets exposés. Néanmoins, les résultats démontrent que des bronchoconstrictions répétées ne sont pas suffisantes pour induire plusieurs aspects du remodelage des voies aériennes, pour altérer la mécanique respiratoire et pour modifier la capacité contractile du muscle lisse trachéal. L’hypothèse du deuxième projet stipule que l’activation répétée des récepteurs muscariniques du muscle lisse des voies aériennes donne lieu à un phénomène d’adaptation des récepteurs. Ce phénomène se répercuterait en une diminution de l’effet de la métacholine sur la force générée par le muscle lisse des voies aériennes et, conséquemment, en une diminution de l’obstruction des voies respiratoires. Les résultats confirment que l’activation répétée des récepteurs muscariniques par l’administration de métacholine à des souris in vivo diminue leur réactivité bronchique à la métacholine, et ce, en diminuant la capacité contractile du muscle lisse des voies aériennes en réponse à la métacholine. De façon encore plus impressionnante, dans un modèle murin d’asthme, ce traitement permet de renverser complètement l’hyperréactivité bronchique à la métacholine. Les mécanismes moléculaires sous-jacents restent à être élucidés. / Asthma is a prevalent respiratory disorder for which a proportion of patients responds poorly to actual treatment, which highlights the necessity to study the physiopathology of asthma and to develop more efficient drugs. The airway smooth muscle plays a chief role in asthma. This is because the excessive activation of airway smooth muscle that characterizes asthma, and the exaggerated contraction that ensues, leads to respiratory symptoms by obstructing the airway lumen. The two projects presented in this Master’s thesis focus on the effects of repeated inhalations of methacholine, an activator of airway smooth muscle, in mice. The hypothesis of the first project postulated that the mechanical stress the airway wall undergoes during repeated methacholine-induced constrictions leads to structural changes in the airway wall. The results demonstrated that repeated constrictions by themselves are not sufficient to induce key features of airway wall remodeling, to alter respiratory mechanics and to change the contractile capacity of airway smooth muscle. The hypothesis of the second project postulated that repeated inhalations of methacholine trigger adaptation of the muscarinic receptors, which leads to a decreased effect of muscarinic agonists over time. In turn, this would decrease the force generated by airway smooth muscle and thereby relieves airway obstruction. The results confirmed that repeated activations of the muscarinic receptors by inhaled methacholine decrease airway responsiveness to methacholine in vivo, as well as the force generated by the airway smooth muscle in response to methacholine ex vivo. Interestingly, in a murine model of asthma, repeated activations of the muscarinic receptors completely reverse airway hyperresponsiveness to methacholine. The molecular mechanisms underlying this phenomenon remain to be determined.

Dry powder inhalers (DPIs) are commonly used to deliver drugs to the lungs. The drug particles used in these DPIs should possess a number of key properties. These include an aerodynamic particle size < 5μm and particle crystallinity for long term formulation stability. The conventionally used micronization technique to produce inhalation particles offers limited opportunities to control and optimize the particle characteristics. It is also known to induce crystalline disorder in the particles leading to formulation instability. Hence, this research project investigates and optimizes a solvent/anti-solvent crystallization process capable of directly yielding inhalation particles using albuterol sulfate (AS) as a model drug. Further, the feasibility of the process to produce combination particles of AS and ipratropium bromide monohydrate (IB) in predictable proportions and in a size suitable for inhalation is also investigated. The solvent / anti-solvent systems employed were water / ethyl acetate (EA) and water / isopropanol (IPA). Investigation and optimization of the crystallization variables with the water / EA system revealed that particle crystallinity was significantly influenced by an interaction between the drug solution / anti-solvent ratio (Ra ratio), stirring speed and crystal maturation time. Inducing a temperature difference between the drug solution and anti-solvent (Tdrug solution > Tanti-solvent) resulted in smaller particles being formed at a positive temperature difference of 65°C. IPA was shown to be the optimum anti-solvent for producing AS particles (IPA-AS) in a size range suitable for inhalation. In vitro aerosol performance of these IPA-AS particles was found to be superior compared to the conventionally used micronized particles when aerosolized from the Novolizer®. The solvent / anti-solvent systems investigated and optimized for combination particles were water / EA, water / IPA, and water / IPA:EA 1:10 (w/w). IPA was found to be the optimum anti-solvent for producing combination particles of AS and IB with the smallest size. These combination particles showed uniform co-deposition during in vitro aerosol performance testing from the Novolizer®. Pilot molecular modeling studies in conjunction with the analysis of particle interactions using HINT provided an improved understanding of the possible interactions between AS and IB within a combination particle matrix.

This research was aimed at the development and validation of new in vitro methods capable of predicting in vivo drug deposition from dry powder inhalers, DPIs, in lung-normal human adults. Three physical models of the mouth, throat and upper airways, MT-TB, were designed and validated using the anatomical literature. Small, medium and large versions were constructed to cover approximately 95% of the variation seen in normal adult humans of both genders. The models were housed in an artificial thorax and used for in vitro testing of drug deposition from Budelin Novolizer DPIs using a breath simulator to mimic inhalation profiles reported in clinical trials of deposition from the same inhaler. Testing in the model triplet produced results for in vitro total lung deposition (TLD) consistent with the complete range of drug deposition results reported in vivo. The effect of variables such as in vitro flow rate were also predictive of in vivo deposition. To further assess the method’s robustness, in vitro drug deposition from 5 marketed DPIs was assessed in the “medium” MT-TB model. With the exception of Relenza Diskhaler, mean values for %TLD+SD differed by only < 2% from their literature in vivo. The relationship between inhaler orientation and in vitro regional airway deposition was determined. Aerosol drug deposition was found to depend on the angle at which an inhaler is inserted into the mouth although the results for MT deposition were dependent on both the product and the formulation being delivered. In the clinic, inhalation profiles were collected from 20 healthy inhaler naïve volunteers (10M, 10F) before and after they received formal inhalation training in the use of a DPI. Statistically significant improvements in Peak Inhalation Flow Rate (PIFR) and Inhalation Volume (V) were observed following formalized training. The shapes of the average inhalation profiles recorded in the clinic were found to be comparable to the simulated profiles used in the in vitro deposition studies described above. In conclusion, novel in vitro test methods are described that accurately predict both the average and range of aerosol airway drug deposition seen from DPIs in the clinic.

La pyrazinamide est le seul anti-tuberculeux de première intention actif sur la formedormante de Mycobacterium tuberculosis. Sa prescription par voie orale permet de réduire la durée du traitement de 9 à 6 mois. Nous avons développé des formes galéniques de pyrazinamide administrables directement au niveau des poumons afin d'augmenter localement la concentration de pyrazinamide au site pathologique afin de réduire la durée du traitement. Deux formes galéniques de pyrazinamide ont été optimisées: une poudre sèche pour inhalation et des nanoparticules polymères administrables par nébulisation liquide ou sous forme de poudre sèche.La poudre sèche pour inhalation est composée de particules obtenues par atomisation-séchage. La pyrazinamide a été solubilisée dans un mélange 70/30 v/véthanol/eau. Après atomisation-séchage de cette solution, nous avons obtenu des particules cristallines instables et non adaptées à l'administration pulmonaire du fait de leur grande taille. Afin d'obtenir des poudres adaptées à une administration pulmonaire dans le poumon profond, et stables en termes de taille et de caractéristiques physico-chimiques, nous avons passé en revue toute une série d'excipients: phospholipides, bicarbonate d'ammonium, leucine, acide hyaluronique.Nous avons montré qu'en associant tous ces excipients au principe actif, on pouvait obtenir des particules d'environ 6 microns, de faible densité tassée et stables pendant 4 semaines dans des conditions de stockage classiques.L'évaluation aérodynamique in vitro de la poudre optimisée a révélé l'existence de deux populations de particules: de grosses particules pauvres en pyrazinamide et de petites particules riches en pyrazinamide. Ces deux populations proviennent d'une ségrégation des différents composants lors du processus de séchage. Pour remédier à ce phénomène et obtenir des particules de composition homogène, la vitesse de séchage a été diminuée. En conséquence, nous avons obtenu des poudres homogènes avec de bonnes propriétés aérodynamiques pour délivrance dans les poumons: fraction de particules fines de 40,1 ± 1,0% et fraction alvéolaire de 29,6 ±3,1%. Cette poudre a alors été évaluée in vivo chez le rat sain et nous avons mesuré les concentrations de pyrazinamide dans le plasma et le liquide de lavage bronchoalvéolaire après insufflation intratrachéale de la poudre, par comparaison avec une administration intraveineuse d'une solution de pyrazinamide. L'insufflation intratrachéale de poudre et l'administration intraveineuse conduisent à des paramètres pharmacocinétiques similaires prouvant que les particules se dissolvent rapidement lors du dépôt et que la molécule traverse efficacement la barrière pulmonaire pour atteindre la circulation systémique. De manière surprenante, la pyrazinamide est éliminée plus rapidement du liquide pulmonaire lorsqu'elle est administrée par insufflation intratrachéale que par voie intraveineuse. La délivrance pulmonaire de pyrazinamide apparaît comme une alternative intéressante à l'administration orale de la molécule et doit maintenant être testée dans un modèle d'animal infecté pour évaluer son efficacité contre Mycobacterium tuberculosis.En parallèle, nous avons optimisé l'encapsulation de pyrazinamide dans des nanoparticules polymères de poly(lactide-co-glycolide) PLGA monodisperses de taille inférieure à 200nm, grâce un plan d'expériences. Les nanoparticules de PLGA chargées en pyrazinamide ont été préparées par la méthode d'émulsion double. La méthode de Taguchi a été utilisée pour optimiser les paramètres de formulation. Le type de solvant, le rapport en poids pyrazinamide/ PLGA et le rapport des volumes des phases aqueuse et organique étaient les paramètres pertinents. La méthode de Taguchi s'est avérée efficace pour optimiser les nanoparticules d'environ 170nm avec un indice de polydispersité ˂ 0,1, un potentiel zêta d'environ -1mV et une efficacité d'encapsulation de 7-8% soit 3% de taux de charge de la pyrazinamide. / Pyrazinamide is the only first intention anti-TB drug active on the dormant form ofMycobacterium tuberculosis. Its oral prescription reduces treatment duration from 9to 6 months. We have developed dosage forms of pyrazinamide to administer directlyto the lungs to locally increase the concentration of pyrazinamide at the diseased siteand further reduce the duration of treatment. Two dosage forms of pyrazinamidewere optimized: a dry powder for inhalation and polymer nanoparticles administrableeither by liquid nebulization or as a dry powder.The dry powder for inhalation is composed of particles obtained by spray-drying.Pyrazinamide was dissolved in a mixture 70/30 v/v ethanol/water. After spray-dryingthe solution, we obtained large crystalline particles that were unstable and notsuitable for pulmonary administration because of their large sizes. To obtain powderssuitable for pulmonary delivery to the deep lungs, and stable in terms of size andphysico-chemical characteristics, we reviewed a variety of excipients: phospholipids,ammonium bicarbonate, leucine, hyaluronic acid. We have shown that by combiningall these excipients with the drug, one could obtain particles of about 6 microns, witha low tapped density and stable for 4 weeks under conditions of conventionalstorage.The in vitro aerodynamic evaluation of the optimized powder showed the existence oftwo populations of particles: large particles with a low content of pyrazinamide andsmall particles with high pyrazinamide content. These two populations derived fromthe segregation of different components during the drying process. To obtainparticles of uniform composition, the drying rate was decreased. As a result, weobtained homogeneous powders with good aerodynamic properties for delivery intothe lungs: fine particle fraction of 40.1 ± 1.0% and alveolar fraction of 29.6 ± 3.1%.This powder was then evaluated in vivo in healthy rats and we measured theconcentrations of pyrazinamide in plasma and bronchoalveolar lavage fluid afterintratracheal insufflation of the powder in comparison with intravenous administrationof a solution of pyrazinamide. The intratracheal insufflation of the powder and theintravenous injection lead to similar pharmacokinetic parameters proving that theparticles dissolve rapidly after deposition and pyrazinamide crosses efficiently thelung barrier to reach the systemic circulation. Surprisingly, pyrazinamide disappears4faster form lung lining fluid when administered by pulmonary insufflation than afterintravenous administration. Pulmonary delivery of pyrazinamide appears as anattractive alternative to oral administration of the drug and must now be tested in ananimal model of infection to assess its efficacy against Mycobacterium tuberculosis.In parallel, we have optimized the encapsulation of pyrazinamide in polymericnanoparticles of poly (lactide-co-glycolide) PLGA lower than 200 nm andmonodisperse, using experimental design. The pyrazinamide-loaded PLGAnanoparticles were prepared by the double emulsion method. The Taguchi methodwas used to optimize the formulation parameters. The type of solvent, thepyrazinamide / PLGA weight ratio and aqueous to organic phases volume ratio wererelevant parameters. The Taguchi method has proven effective to optimizenanoparticles of about 170nm with a polydispersity index < 0.1, a zeta potential ofapproximately -1mV and an encapsulation efficiency of 7-8% or 3% pyrazinamide drugloading.

Nosso objetivo foi avaliar o efeito do oxigênio (O2) e dos broncodilatadores (BD) sozinhos ou associados, no alívio da dispnéia e desempenho físico. Foram feitas inalação de 5 mg de salbutamol + 500 ug de brometo de ipratrópio seguidas de teste dos seis minutos com O2 ou ar comprimido em 28 pacientes com DPOC, dispnéia aos esforços e SaO2 menor que 89%. Resultados: a distância no teste de caminhada aumentou de 356 (128)m para 377(117)m após BD (p menor 0,05), para 406 (109)m após O2 (p=0,011 comparado com BD+ar e p=0,001 quando comparado com inalação placebo+ar). A dispnéia foi significantemente menor somente com a combinação do O2 com BD e o efeito do oxigênio na capacidade física foi potencializado pela administração prévia de BD / Our objective was assess the effect of oxygen (O2) and bronchodilator (BD) on reduce exertional breathlessness and improve exercise tolerance in patients with COPD. Nebulization of 5 mg of salbutamol plus 500 ug ipratropium bromide followed by a six-minute walking test while breathing O2 were studient in 28 patients with severe COPD, breathless on exertion and with SaO2 menor que 89%. Results: The distance increased from 356 (128)m to 377 (117)m after the BD (p menor 0,05), to 406 (109)m after O2 (p 0,001 vs placebo/air). End-exercise dyspnoea only fell significantly when O2 and BD were combined and the effect of O2 on exercise preformance was improvement with therapies combined

Introdução: A pneumonia associada à ventilação mecânica (PAV) causada por Staphylococcus aureus resistente à meticilina (SARM) é uma infecção nosocomial frequente em pacientes críticos. A vancomicina é o tratamento de escolha, porém tem apresentado altas taxas de falha terapêutica, sendo uma das possíveis causas a baixa penetração no tecido pulmonar após administração intravenosa. Diversos estudos experimentais têm demonstrado que a administração de antibióticos por nebulização possibilita a obtenção de altas concentrações no tecido pulmonar e maior efeito bactericida que a obtida por infusão intravenosa. Entretanto, até o momento, a literatura carece de estudos comparando a utilização de vancomicina por via intravenosa com a via inalatória. Objetivo: O objetivo principal deste estudo foi comparar a concentração de vancomicina atingida no tecido pulmonar saudável após a administração de dose única via intravenosa ou por nebulização, em suínos anestesiados e submetidos à ventilação mecânica. Métodos: Vinte e quatro suínos foram submetidos à anestesia intravenosa, intubação e ventilação mecânica e aleatorimanete distribuidos: Doze animais receberam uma dose única de vancomicina por infusão intravenosa (15 mg.Kg-1), dos quais seis animais foram eutanasiados uma hora após término da administração e seis animais foram eutanasiados após 12 horas e doze animais receberam uma dose única de vancomicina por nebulização com nebulizador de placa vibratória (37,5 mg.Kg-1), dos quais seis animais foram eutanasiados uma hora após término da administração e seis animais foram eutanasiados após 12 horas. Foram coletadas amostras de sangue para dosagem sérica de vancomicina antes da administração em 30\', 1, 2, 4, 6, 8 e 12h após o término da administração. Após a eutanásia, foram coletadas amostras de tecido pulmonar de regiões dependentes e não dependentes para dosagem tecidual de vancomicina. Nos animais que receberam a vancomicina por nebulização, a deposição extrapulmonar deste antibiótico foi calculada após da lavagem das partes do circuito ventilatório e da câmara de nebulização. A dosagem de vancomicina foi realizada por meio de cromatografia líquida de alta eficiência (CLAE-UV). Resultados: A concentração de vancomicina no tecido pulmonar obtida no grupo nebulizado de uma hora foi aproximadamente treze vezes maior que a concentração pulmonar obtida no grupo intravenoso de uma hora; (mediana e intervalo interquartílico) 161 (71-301) vs. 12 (4-42) Mig.g-1 (p < 0,05), respectivamente. A concentração pulmonar de vancomicina no grupo nebulizado de 12 horas foi 63 (23-119) Mig.g-1 e níveis indetectáveis de vancomicina foram obtidos no grupo intravenoso de 12 horas; 0 (0-19) Mig.g-1 (p < 0,05). Houve ausência de um pico sérico de vancomicina após o término da administração por nebulização no grupo de doze horas comparado ao grupo intravenoso. Conclusão: A administração de vancomicina por nebulização apresentou maiores concentrações pulmonares do que pela via intravenosa. Os resultados sugerem uma passagem lentificada da vancomicina pela barreira alvéolo-capilar após nebulização / Introduction: Ventilator-associated pneumonia caused by Staphylococcus aureus methicillin resistant is a frequent nosocomial infection in critically ill patients. Vancomycin is the treatment of choice, but it has presented high rates of therapeutic failure, possibly due to its low penetration in lung tissue following intravenous administration. Many studies have shown that lung tissue deposition and antibacterial efficiency of nebulized antibiotics were greater than by intravenous administration. However, to date, the literature lacks studies comparing the use of vancomycin intravenously with the inhalation route Objective: The aim of this study was to compare vancomycin concentration in healthy lungs after a single dose nebulized or intravenously administered in anesthetized and ventilated piglets. Methods: Twenty four piglets were anesthetized, intubated and submitted to mechanical ventilation. Twelve animals received a single dose of vancomycin by intravenous infusion (15 mg.kg-1), of which six animals were euthanized one hour after the end of administration and six animals were euthanized after 12 hours and twelve animals received a single dose of vancomycin using a vibrating plate nebulizer (37,5 mg.kg-1), of which six animals were euthanized one hour after the end of administration and six animals were euthanized after 12 hours. Blood samples were collected for serum vancomycin dosage before and at 30\', 1, 2, 4, 6, 8 and 12 hours after the end of administration. After euthanasia, tissue samples from dependent and non-dependent lung tissue were collected for tissue dosage of vancomycin. In animals receiving vancomycin by nebulization, the extrapulmonary deposition of this antibiotic was calculated after washing the parts of the ventilator circuit and the nebulization chamber. The dosage of vancomycin was performed using high performance liquid chromatography (HPLC-UV). Results: Vancomycin lung tissue concentrations in one-hour aerosol group were thirteen times greater than pulmonary concentration in one-hour intravenous group (median and interquartile range): 161 (71-301) Mig.g-1 vs. 12 (4-42) Mig.g-1 (p < 0.05). Vancomycin lung tissue concentration in twelve-hour aerosol group was 63 (23-119) ?g.g-1 and it was undetectable in twelve-hour intravenous group; 0 (0-19) Mig.g-1 (p < 0.05). There was no vancomycin serum peak following the end of administration by nebulization in the 12-hour group compared to intravenous administration. Conclusion: Administration of vancomycin by nebulization showed higher lung tissue concentrations than intravenous route. The results suggest a slower passage of vancomycin through alveolar capillary barrier after nebulization