CHARLES UNIVERSITY Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Name of author: Dominik Vavřich Title of diploma thesis: Rheological behaviour of mixtures for freeze-drying Supervisor: PharmDr. Eva Šnejdrová, Ph.D. The diploma thesis deals with the evaluation of rheological properties of aqueous dispersions of fish gelatin and carrageenans intended for lyophilization. Theoretical part of this work is dedicated to the characterization of fish gelatin and carrageenans which were used for preparation of the mixtures in experimental part of this work. Characterization of an oral cavity from an application of medicaments point of view and an orally disintegrating tablets of the medicine with a focus on the lyophilized tablets are also presented. Mixtures of the fish gelatin and the carrageenans were prepared in the experimental part of the work. Their rheological behaviour employing an absolute rotational rheometer Kinexus Pro+ was measured and evaluated. Also, the testing of the rheological characteristics of these materials transformed into the freeze-dried tablets was performed. Nonlinear viscous curves were obtained, and they were mathematically evaluated by the Power law model. Pseudoplastic behaviour of the mixtures can be derived from the results of acquired...

Using various synthetic strategies, we designed several libraries of novel polysaccharide mixed ester derivatives for oral drug delivery applications. Cellulose and cellulose esters have been extensively studied and utilized for different applications such as separation membranes, sustainable plastics, and enteric coatings in oral drug delivery carriers. We sought to exploit the ring-opening of cyclic anhydrides, succinic and glutaric anhydride, to append ω-carboxyl groups to commercially available cellulose and cellulose ester substrates. We used scalable synthetic strategies and widely available and cheap reagents to show a proof-of-concept for the manufacturability of these different polymer derivatives. We incorporated different degrees of substitution of ω-carboxyl groups to impart a range of water solubility in these polymers. The derivatives displayed excellent <i>T</i>g values for ASD applications, adequate water solubility, and good amphiphilic properties. We designed very effective amorphous solid dispersion (ASD) oral drug delivery polymers that prevented recrystallization of felodipine for hours and had excellent congruent polymer-drug release from the formulation at 20% drug loading. During the ring-opening reactions of the cellulose derivatives with glutaric anhydride we discovered that crosslinking and gelation can occur, especially with cellulose and cellulose ester substrates with a high degree of substitution (DS) of hydroxy groups. We isolated and characterized these gelled products using rheology, and solid-state 1D and 2D NMR spectroscopy, to evaluate whether the gels are physical or chemical in nature and proposed a mechanism for gelation. We determined that the gels are mostly physical but can proceed to chemical crosslinking over time. We designed a library of cellulose ester derivatives, and we investigated their performance as amorphous solid dispersion (ASD) drug delivery vehicles for the lipophilic drug felodipine, through <i>in vitro</i> experiments. Aside from felodipine, many other active pharmaceutical ingredients (APIs) are also highly crystalline and poorly water-soluble. ASDs are used to disrupt the crystalline packing of these drugs through dispersing them in amorphous polymeric carriers, facilitating their water-solubility, and preventing their recrystallization. We showed that our polymers performed remarkably well in the <i>in vitro</i> studies and inhibited crystallization of model compound felodipine for several hours while providing optimal drug release, affording highly promising ASD polymers. If company formulators are unable to develop an effective oral-delivery carrier to prevent a drug from recrystallizing, then the drug cannot be tested in <i>in vivo</i> toxicology studies, and therefore cannot be brought to market because of its poor aqueous solubility and subsequent low bioavailability. To test the robustness of our polymers, we also performed <i>in vitro</i> ASD experiments at the pharmaceutical company AbbVie with their most rapidly crystallizing pipeline compounds, and several commercially available drugs (Compound A, axitinib, and ziprasidone). We demonstrated that our polymers could also prevent drug recrystallization with these rapid crystallizers, outperforming commercial polymers like FDA-approved hydroxypropyl methyl cellulose acetate succinate (HPMCAS (MF)), even at exceptionally high drug loading ratios of 40 times the concentration of polymer. α-1,3-Glucans are an emerging class of polysaccharides and are structurally different than cellulose due to their α (1→3) linkage versus the cellulose β (1→4) glycosidic linkage. We demonstrated that we could modify these derivatives using a variety of esterification strategies and TEMPO-mediated C6 selective oxidation, affording a myriad of different novel polymer products, some of which are structural analogs of the cellulose ester derivatives we previously created. The polymers had higher <i>T</i>g values than the cellulose ester polymers, which may be useful for applications where heat resistance is desired. In the future, we will screen some of these α-1,3-glucan derivatives with poorly water-soluble enzalutamide, posaconazole and celecoxib model drugs, to evaluate their crystallization inhibition properties and the influence of polymer morphology upon structure-property relationships. We expect that these synthetic polymer strategies will offer scalable routes to novel ASD polymers, which we demonstrated to be highly effective drug crystallization inhibitors against a variety of different hydrophobic pharmaceutical compounds. / Doctor of Philosophy / Polysaccharides are polymers comprised of many linked sugar molecules and are an incredibly abundant and renewable resource. They are found everywhere in nature such as the wood from trees, the shells of crabs, the exoskeletons of bugs, and the mushrooms that sprout in damp forests. The research in this dissertation focuses on the use and chemical modification of polysaccharides for designing new, polysaccharide-based oral drug delivery systems called amorphous solid dispersions (ASDs), which significantly aid in the solubility and bioavailability of important medications. We started with the chemical modification of cellulose, the most abundant plant polysaccharide on planet Earth, and previously modified commercial cellulose substrates (known as cellulose esters) to create novel polymers for ASDs. We successfully modified these polymers, characterized them, and evaluated their potential as oral drug delivery vehicles by formulating them with several different classes of potent drugs used to treat a variety of diseases such as hypertension and schizophrenia. We showed that our designed cellulose ester polymers kept these hydrophobic drugs water-soluble for long-enough so that they can be adequately absorbed in the human body through the gastrointestinal tract, significantly outperforming commercial polymers in many cases. During the chemical modification of the cellulose esters, we also observed that they were prone to form gels, and we investigated this gelation phenomena in more detail through rheometry, 1D and 2D solid-state nuclear magnetic resonance spectroscopy (similar in principle to the medical diagnostic method, magnetic resonance imaging or MRI). We discovered that these gels can be physically and/or chemically linked together, and that different gelation mechanisms can dominate depending on the polysaccharide substrate and the esterification reagent used. We extended our research to other polysaccharide derivatives called α-1,3-glucans, which can be sourced from fungi, and/or enzymatically synthesized in the lab. Using various synthetic esterification and oxidation chemical methods to functionalize this polysaccharide, we designed a library of entirely novel polymers with different physical structures relative to the cellulose ester polymers. The polymers displayed thermal properties that show promise in drug delivery vehicle applications and in applications where high heat resistance is required. Overall, we developed next-generation polymers for amorphous solid dispersion oral drug delivery applications. We displayed the versatility of using a select few chemistry strategies to create a variety of different polymers with very different physicochemical properties. We hope that this work will help researchers design sustainable, plant-based polymers for ASD applications and we hope to nurture future structure-function studies to improve ASD performance for the benefit of patients in need.

The purpose of this study was to improve the melt extrusion processability of polyvinyl acetate phthalate (PVAP) and investigate its use as a stabilizing polymer for supersaturated solutions of itraconazole (ITZ) in neutral pH aqueous media and in the solid-state during storage over time. Polyvinyl pyrrolidone vinyl acetate (PVPVA) was incorporated into PVAP as a carrier matrix with the aim of lowering the melt viscosity and increasing the plasticity of PVAP while maintaining its high glass transition temperature (Tg). Amorphous solid dispersions of ITZ (40% w/w) in a 30:70% w/w PVAP:PVPVA mixture were produced by melt extrusion. Solid-state analyses of the composition were performed using differential scanning calorimetry and X-ray diffraction. Dissolution analysis was conducted using a pH-change method. Solid-state analyses demonstrated that the extruded composition was entirely amorphous and ITZ was largely distributed in PVAP- and PVPVA-rich portions of the ternary dispersion. Dissolution analysis revealed that PVAP functioned to prolong the release of supersaturated levels of ITZ from the dispersion following an acidic-to-neutral pH transition. In the solid state, ITZ remained in its amorphous form throughout 6 months of storage. The results of this study suggest that substantial improvements in melt extrusion with PVAP can be achieved by incorporating PVPVA and that the PVAP-PVPVA polymer combination can stabilize amorphous ITZ. / Pharmaceutical Sciences

Process Analytical Technology (PAT) is framed with the objective of the design and development of processes to ensure predefined quality of the product at the end of manufacturing. PAT implementation includes better understanding of process, reduction in production time with use of in-line, at-line and on-line measurements, yield improvement and energy and cost reductions. Hot Melt Extrusion process (HME) used in the present work is proving increasingly popular in industry for its continuous and green processing which is beneficial over traditional batch processing. The present work was focused on applications of Raman spectroscopy as off - line and in - line monitoring techniques as a PAT for production of pharmaceutical solid dispersions and co-crystals. Solid dispersions (SDs) of the anti-convulsant Carbamazepine (CBZ) with two pharmaceutical grade polymers have been produced using HME at a range of drug loadings and their amorphous nature confirmed using a variety of analytical techniques. Off-line and in-line Raman spectroscopy has been shown to be suitable techniques for proving preparation of these SDs. Through calibration curves generated from chemometric analysis in-line Raman spectroscopy was shown to be more accurate than off-line measurements proving the quantification ability of Raman spectroscopy as well as a PAT tool. Pure co-crystals of Ibuprofen-Nicotinamide and Carbamazepine-Nicotinamide have been produced using solvent evaporation and microwave radiation techniques. Raman spectroscopy proved its superiority over off-line analytical techniques such as DSC, FTIR and XRD for co-crystal purity determination adding to its key advantage in its ability to be used as an in-line, non-destructive technique.

Made available in DSpace on 2017-07-21T14:13:13Z (GMT). No. of bitstreams: 1 Fabiula Franke.pdf: 1832049 bytes, checksum: 9f31a658c71b761b6dda69c029bbafb4 (MD5) Previous issue date: 2014-02-26 / The ferulic acid has antioxidant, anti-inflammatory, antithrombotic, anticancer, neuroprotective, cardioprotective and photoprotective activity. However, despite these biological activities, its therapeutic usefulness is limited due to certain unfavorable physicochemical properties, especially the low aqueous solubility. It is classified as a Class II drug by the Biopharmaceutical Classification System and therefore its dissolution is a limiting step of absorption, may present bioavailability problems. Thus, considering the large number of pharmacological properties attributed to ferulic acid, the aim of this study was to develop and characterize solid dispersions containing ferulic acid, hydrophobic, a non-ionic surfactant (Poloxamer 407) and compare them in terms of improving the dissolution of ferulic acid. Solid dispersions were obtained by methods of crushing, kneading, co-evaporation, fusion, spray drying and freeze drying at concentrations of 10 and 20%. The formulations showed a yield between 38.6 and 80.2%. All formulations showed adequate amounts of efficiency of incorporation, greater than 80%. The solid dispersions were characterized by scanning electron microscopy, X-ray diffraction and spectroscopy in the infrared region in Fourier transform, whose results confirmed the acquisition of solid dispersions. The dissolution characteristics of the pure drug and the formulations were compared. Solid dispersions exhibited greater efficiency in improving the speed of dissolution of the ferulic acid, explainable by the effect of Poloxamer 407 surfactant. A highest increase of dissolving was obtained with the formulation obtained by the method of freeze drying at a concentration of 10%, with dissolution efficiency of 93.83%. The dissolution profiles showed the best fit to a monoexponential equation. These results suggest that the solid dispersions prepared with the use of Poloxamer 407, containing the drug, are strategies feasible in the pharmaceutical industry. / O ácido ferúlico tem atividade antioxidante, anti-inflamatória, antitrombótica, anticancerígena, neuroprotetora, cardioprotetora e fotoprotetora. No entanto, apesar dessas atividades biológicas, sua utilidade terapêutica é limitada devido a certas propriedades físico-químicas desfavoráveis, notadamente a baixa solubilidade aquosa. É qualificado como fármaco da Classe II pelo Sistema de Classificação Biofarmacêutica e, portanto, sua dissolução é etapa limitante da absorção, podendo apresentar problemas de biodisponibilidade. Assim, considerando o elevado número de propriedades farmacológicas atribuídas ao ácido ferúlico, o objetivo desse trabalho foi desenvolver e caracterizar dispersões sólidas contendo ácido ferúlico, hidrofóbico, e um surfactante não-iônico Poloxamer 407 e compará-las quanto à melhoria na dissolução do ácido ferúlico. As dispersões sólidas foram obtidas pelos métodos de trituração, malaxagem, coevaporação, fusão, liofilização e spray-drying nas concentrações de 10 e 20%. As formulações apresentaram um rendimento entre 38,6 e 80,2%. Todas as formulações mostraram valores de eficiência de incorporação adequados, superiores a 80%. As dispersões sólidas foram caracterizadas por microscopia eletrônica de varredura, por difração de raios X e por espectroscopia na região do infravermelho com transformada em Fourier, cujos resultados comprovaram a obtenção das dispersões sólidas. As características de dissolução entre o fármaco puro e as formulações foram comparadas. As dispersões sólidas apresentaram maior eficiência em melhorar a velocidade de dissolução do ácido ferúlico, explicável pelo efeito tensoativo do Poloxamer 407. Maior incremento da dissolução foi obtido com a formulação obtida pelo método de liofilização na concentração de 10%, com eficiência de dissolução de 93,83%. Os perfis de dissolução apresentaram o melhor ajuste para a equação monoexponencial. Esses resultados sugerem que as dispersões sólidas elaboradas com o uso do Poloxamer 407, contendo o fármaco, são estratégias viáveis na indústria farmacêutica.

Este trabalho visou obter extratos secos padronizados de Curcuma longa L., e sua otimização visando o aumento da solubilidade dos curcuminóides e melhoria nas suas atividades biológicas. No estudo de extração, os curcuminóides foram extraídas utilizando dois solventes, etanol e solução etanólica alcalina e dois processos microondas e ultrassom seguindo planejamentos fatoriais completos 24, e com pH do solvente, teor de etanol, tempo de extração, potência do microondas ou temperatura no ultrassom, e proporção massa da droga pela massa do solvente como variáveis independentes. Os extratos foram caracterizados quanto ao rendimento de sólidos totais, teor de curcuminóides totais, rendimento de curcuminóides totais, teor de curcumina, rendimento de curcumina e atividade antioxidante por difenil-picril-hidrazila. A condição de extração com melhor resultado foi o ultrassom a 20 ºC, solvente etanol 96 ºGL, 1 parte de planta para 7 de solvente, pH 10 e duração de 5 min., pois, nesta condição, obteve-se maior teor de curcumina e maior atividade antioxidante. O estudo visando aumento da solubilidade da curcumina constou da preparação de dispersões sólidas pelos métodos de spray drying e hot melt coating. Ambos os métodos foram estudados com os polímeros hidrofílicos Gelucire® 44:14 e 50:13, e aplicando-se planejamento fatorial tipo Box-Behnken. As dispersões sólidas particuladas foram avaliadas pela morfologia, densidade aparente e de compactação, fator de Hausner, índice de Carr, ângulo de repouso, umidade residual, atividade de água, calorimetria diferencial de varredura, termogravimetria, difração de raio-X, espectrometria de infravermelho, solubilidade em água e teste de dissolução. A maior solubilidade foi obtida com secagem no spray drying a 40 ºC, proporção Gelucire®44/14:curcumina 1:1 e proporção 1:5 de Aerosil:dispersão (DS16). No hot melt coating, a melhor solubilidade foi obtida com maior quantidade de Gelucire 50/13 e menor de Lactose (DS 3). Dispersões sólidas particuladas foram preparadas também com o Gelucire® 50/13 por spray drying (DS 17). Considerando-se os fatores solubilidade e teor de curcumina nas partículas, a dispersão DS 17 foi escolhida como a mais adequada para os ensaios biológicos posteriores. A mesma condição de preparo da DS17 foi usada para produzir dispersões sólidas com o extrato obtido por ultrassom (DSE). Nesta dispersão a solubilidade dos curcuminóides demonstrou ser 330 vezes maior do que o extrato seco nas mesmas condições porém sem a adição de carreador. No ensaio de avaliação da atividade antitumoral in vitro, foram avaliadas a citotoxicidade da curcumina pura, DS 17, DS 3 e a DSE, em diferentes linhagens tumorais, leucemia T (jurkat), melanona (C8161), adenocarcinoma coloretal (HT29), carcinoma hepatocelular (HepG2) e de célula não tumoral (PBMC). A curcumina apresentou atividade citotóxica para células tumorais e esta não foi afetada pelo processo de produção da dispersão sólida. Além disso, a DS do extrato apresentou maior citotoxicidade, o que pode ser devido ao sinergismo de outros compostos. O extrato também foi mais seletivo para células tumorais que a curcumina e as dispersões. O estudo de atividade anti-inflamatória in vivo usando o modelo de edema de pata, demonstrou que a dispersão DS 17 apresentou maior atividade do que a curcumina na mesma dose, indicando que o aumento da solubilidade possibilita uma maior absorção e consequentemente maior biodisponibilidade. / The aim of this work was to obtain standardized dried extracts of Curcuma longa L. and to develop pre-formulations and capsules with improved curcuminoids solubility and higher biological activities. In the extraction study, the powdered roots of Curcuma longa L. were extracted using ethanol and an aqueous alkaline ethanol solution by microwave and ultrasound assisted methods, together with the application of 24 full factorial designs of experiments to better understand the effects of solvent pH, ethanol concentration, microwave power, ultrasound temperature and ratio of drug to solvent (w/w) on the extract. The extracts were characterized by solids yield, curcuminoid content and yield, curcumin content and yield and antioxidant activity by the diphenylpycril hydrazil method. The best extraction resulted from the ultrasound assisted using ethanol 96 oGL at pH 10, 20oC, 1:7 drug to solvent ratio (w/w), during 5 minutes. This condition was chosen because it resulted in the best yields and antioxidant activities. The work developed to improve curcumin and curcuminoid solubilities was based on the preparation of solid dispersions by spray drying and hot melt coating using the hydrophilic carriers Gelucire® 44:14 and 50:13. Applying Box-Behnken designs the effect of process conditions on microparticulate solid dispersions properties, like morphology, bulk and tapped densities, Hausner factor, Carr index, angle of repose, moisture content, water activity, differential scanning calorimetry, thermogravimetric analysis, X-ray powder diffraction, infrared spectrometry, curcuminoid solubility in water and dissolution rate. The highest improvement in drug solubility was obtained by dispersion prepared by spray drying at 40oC, Gelucire® 44:14/curcumin 1:1 ratio, and adding 16,7% Aerosil (DS16). On the other hand, the hot melt granules with best solubility were prepared with higher Gelucire® 50:13 and lower substrate (lactose) contents (DS3). Additional solid dispersion, DS17, was prepared by spray-drying in the same conditions applied to DS16 but using Gelucire® 50:13 as carrier. Considering the aspects drug solubility and content in solid dispersions, DS17 showed the best performance and the same set of conditions used for its preparation was also applied to produce a solid dispersion containing the raw extract obtained by ultrasound extraction. This solid dispersion increased curcumin solubility by a 330-fold factor. In the in vitro antitumor assays pure curcumin, DS3, DS17 and DSE cytotoxicities were evaluated in several tumor cell lines, leukemia T (jurkat), melanona (C8161), adenocarcinoma coloretal (HT29), hepatic carcinoma (HepG2) and in one non tumor (PBMC). The antitumor activities were not influenced by the thermal processes and the extract presented higher cytotoxicity and better selectivity to tumor cells. The in vivo antinflammatory study was performed by the rat paw edema method and showed that solid dispersion DS17 resulted in antinflammatory effect higher than pure curcumin and indomethacin at some doses. The results are an indicative that the increase in drug solubility may incur in an increase oral bioavailability and that the process proposed herein are adequate for preparation of pre-formulations containing less soluble herbal drugs.

Over the past few decades, amorphous solid dispersions (ASDs) have been of great interest to pharmaceutical scientists to address bioavailability issues associated with poorly water-soluble drugs. ASDs consist of an active pharmaceutical ingredient (API) that is typically dispersed in an inert polymeric matrix. Despite promising advantages, a major concern that has resulted in limited marketed formulations is the physical instability of these complex formulations. Physical instability is often manifested as phase heterogeneity, where the drug and carrier migrate and generate distinct phases, which can be a prelude to recrystallization. One important factor that dictates the physical stability of ASDs is the spatial distribution of API in the polymeric matrix. It is generally agreed that intimate mixing of the drug and polymer is necessary to achieve maximum stabilization, and thus understanding the factors controlling phase mixing and nano-domain structure of ASDs is crucial to rational formulation design. The focus of this thesis work is to better understand the factors involved in phase mixing on the nanometric level and get insights on the role of excipients on overall stabilization of these systems. The central hypothesis of this research is that an intimately mixed ASD will have better physical stability as compared to a partially homogeneous or a non-homogeneous system. Our approach is to probe and correlate phase homogeneity and intermolecular drug-excipient interactions to better understand the physical stability of ASDs primarily using solid-state nuclear magnetic resonance (SSNMR) spectroscopy and other solid-state characterization tools. A detailed investigation was carried out to understand the role of hydrogen bonding on compositional homogeneity on different model systems. A comprehensive characterization of ternary ASDs in terms of molecular interactions and physical stability was studied. Finally, long-term physical stability studies were conducted in order to understand the impact of different grades of a cellulosic polymer on phase homogeneity for two sets of samples prepared via different methods. Overall, through this research an attempt has been made to address some relevant questions pertaining to nano-phase heterogeneity in ASDs and provide a molecular level understanding of these complex systems to enable rational formulation design.

Este trabalho visou obter extratos secos padronizados de Curcuma longa L., e sua otimização visando o aumento da solubilidade dos curcuminóides e melhoria nas suas atividades biológicas. No estudo de extração, os curcuminóides foram extraídas utilizando dois solventes, etanol e solução etanólica alcalina e dois processos microondas e ultrassom seguindo planejamentos fatoriais completos 24, e com pH do solvente, teor de etanol, tempo de extração, potência do microondas ou temperatura no ultrassom, e proporção massa da droga pela massa do solvente como variáveis independentes. Os extratos foram caracterizados quanto ao rendimento de sólidos totais, teor de curcuminóides totais, rendimento de curcuminóides totais, teor de curcumina, rendimento de curcumina e atividade antioxidante por difenil-picril-hidrazila. A condição de extração com melhor resultado foi o ultrassom a 20 ºC, solvente etanol 96 ºGL, 1 parte de planta para 7 de solvente, pH 10 e duração de 5 min., pois, nesta condição, obteve-se maior teor de curcumina e maior atividade antioxidante. O estudo visando aumento da solubilidade da curcumina constou da preparação de dispersões sólidas pelos métodos de spray drying e hot melt coating. Ambos os métodos foram estudados com os polímeros hidrofílicos Gelucire® 44:14 e 50:13, e aplicando-se planejamento fatorial tipo Box-Behnken. As dispersões sólidas particuladas foram avaliadas pela morfologia, densidade aparente e de compactação, fator de Hausner, índice de Carr, ângulo de repouso, umidade residual, atividade de água, calorimetria diferencial de varredura, termogravimetria, difração de raio-X, espectrometria de infravermelho, solubilidade em água e teste de dissolução. A maior solubilidade foi obtida com secagem no spray drying a 40 ºC, proporção Gelucire®44/14:curcumina 1:1 e proporção 1:5 de Aerosil:dispersão (DS16). No hot melt coating, a melhor solubilidade foi obtida com maior quantidade de Gelucire 50/13 e menor de Lactose (DS 3). Dispersões sólidas particuladas foram preparadas também com o Gelucire® 50/13 por spray drying (DS 17). Considerando-se os fatores solubilidade e teor de curcumina nas partículas, a dispersão DS 17 foi escolhida como a mais adequada para os ensaios biológicos posteriores. A mesma condição de preparo da DS17 foi usada para produzir dispersões sólidas com o extrato obtido por ultrassom (DSE). Nesta dispersão a solubilidade dos curcuminóides demonstrou ser 330 vezes maior do que o extrato seco nas mesmas condições porém sem a adição de carreador. No ensaio de avaliação da atividade antitumoral in vitro, foram avaliadas a citotoxicidade da curcumina pura, DS 17, DS 3 e a DSE, em diferentes linhagens tumorais, leucemia T (jurkat), melanona (C8161), adenocarcinoma coloretal (HT29), carcinoma hepatocelular (HepG2) e de célula não tumoral (PBMC). A curcumina apresentou atividade citotóxica para células tumorais e esta não foi afetada pelo processo de produção da dispersão sólida. Além disso, a DS do extrato apresentou maior citotoxicidade, o que pode ser devido ao sinergismo de outros compostos. O extrato também foi mais seletivo para células tumorais que a curcumina e as dispersões. O estudo de atividade anti-inflamatória in vivo usando o modelo de edema de pata, demonstrou que a dispersão DS 17 apresentou maior atividade do que a curcumina na mesma dose, indicando que o aumento da solubilidade possibilita uma maior absorção e consequentemente maior biodisponibilidade. / The aim of this work was to obtain standardized dried extracts of Curcuma longa L. and to develop pre-formulations and capsules with improved curcuminoids solubility and higher biological activities. In the extraction study, the powdered roots of Curcuma longa L. were extracted using ethanol and an aqueous alkaline ethanol solution by microwave and ultrasound assisted methods, together with the application of 24 full factorial designs of experiments to better understand the effects of solvent pH, ethanol concentration, microwave power, ultrasound temperature and ratio of drug to solvent (w/w) on the extract. The extracts were characterized by solids yield, curcuminoid content and yield, curcumin content and yield and antioxidant activity by the diphenylpycril hydrazil method. The best extraction resulted from the ultrasound assisted using ethanol 96 oGL at pH 10, 20oC, 1:7 drug to solvent ratio (w/w), during 5 minutes. This condition was chosen because it resulted in the best yields and antioxidant activities. The work developed to improve curcumin and curcuminoid solubilities was based on the preparation of solid dispersions by spray drying and hot melt coating using the hydrophilic carriers Gelucire® 44:14 and 50:13. Applying Box-Behnken designs the effect of process conditions on microparticulate solid dispersions properties, like morphology, bulk and tapped densities, Hausner factor, Carr index, angle of repose, moisture content, water activity, differential scanning calorimetry, thermogravimetric analysis, X-ray powder diffraction, infrared spectrometry, curcuminoid solubility in water and dissolution rate. The highest improvement in drug solubility was obtained by dispersion prepared by spray drying at 40oC, Gelucire® 44:14/curcumin 1:1 ratio, and adding 16,7% Aerosil (DS16). On the other hand, the hot melt granules with best solubility were prepared with higher Gelucire® 50:13 and lower substrate (lactose) contents (DS3). Additional solid dispersion, DS17, was prepared by spray-drying in the same conditions applied to DS16 but using Gelucire® 50:13 as carrier. Considering the aspects drug solubility and content in solid dispersions, DS17 showed the best performance and the same set of conditions used for its preparation was also applied to produce a solid dispersion containing the raw extract obtained by ultrasound extraction. This solid dispersion increased curcumin solubility by a 330-fold factor. In the in vitro antitumor assays pure curcumin, DS3, DS17 and DSE cytotoxicities were evaluated in several tumor cell lines, leukemia T (jurkat), melanona (C8161), adenocarcinoma coloretal (HT29), hepatic carcinoma (HepG2) and in one non tumor (PBMC). The antitumor activities were not influenced by the thermal processes and the extract presented higher cytotoxicity and better selectivity to tumor cells. The in vivo antinflammatory study was performed by the rat paw edema method and showed that solid dispersion DS17 resulted in antinflammatory effect higher than pure curcumin and indomethacin at some doses. The results are an indicative that the increase in drug solubility may incur in an increase oral bioavailability and that the process proposed herein are adequate for preparation of pre-formulations containing less soluble herbal drugs.

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

The pharmaceutical industry is at a critical juncture. With little remnants of the “Golden Age of the Pharmaceuticals” and applied pressure from large companies experiencing a dissipation of proprietary compounds, trends indicate a transition from a decade of stagnant productivity to one in which high throughput screening technologies and computational chemistry have diversified the discovery of new chemical entities (NCE). Despite these advances, drug discovery has been challenged by chemical entities that present delivery limitations due to the properties of their molecular structure. A recent evaluation of development pipelines indicated that approximately 70% of drug candidates exhibit poor aqueous solubility; thereby, resulting in erratic dissolution and insufficient bioavailability. Due to intrinsic physical properties, these compounds are known by the biopharmaceutics classification system (BCS) as class II compounds and are amendable to solubility and bioavailability enhancement platforms. Approaches such as pH adjustment, micronization, nanosuspensions, co-solvent solubilization, cyclodextrin inclusion complexation, salt formation, emulsified drug formulations and amorphous solid dispersions (ASD) are commonly utilized to maximize bioavailability and enrich in vivo absorption by prolonging exposure to high concentrations of dissolved drug in the gastrointestinal tract (GIT). Single-phase amorphous systems, such as solid dispersions, have been the focal point of the aforementioned practices as a result of their ability to promote a state of drug supersaturation over an extended duration of time. Within the structure of this dissertation, the application of concentration enhancing polymers for bioavailability enhancement of low solubility compounds was evaluated using solvent and fusion-based solid dispersion technologies. Exploiting a variety of analytical methodologies and tools, formulations produced by spray drying and hot melt extrusion (HME) techniques were investigated for sufficient dissolution enhancement. Studies revealed the selected formulation approaches provided a viable platform for manufacturing solid dispersions by illustrating systems that offered rapid and prolonged periods of supersaturation. While of the applications of single-phase amorphous solid dispersions are continuously expanding, their dissolution behavior is not as well understood. The overarching objective of dissolution testing during formulation development is to achieve biological relevance and predict in vivo performance. Proper in vitro dissolution testing can convey the influence of key in vivo performance parameters and be implemented for assessment and comparison of ASD formulations. Studies suggest that existing research fails to accurately address the intricacies associated with the supersaturated state. Upon solvation and during transit in the GIT, several high-energy drug-containing species are present in addition to free drug. Although these species are not absorbed in vivo, they play a pivotal role in generating and maintaining the supersaturation of a drug substance and function to replenish the supply of free drug as it permeates across the gastrointestinal membrane. Established dissolution apparatuses and methodologies in the United States Pharmacopeia (USP) focus on evaluation of total dissolved drug and may not be physiologically relevant for determining the amount of drug absorbed in vivo. Within the framework of this dissertation, a dissolution methodology was designed to reflect the physiochemical, physiological and hydrodynamic conditions that transpire throughout dissolution and absorption of an ASD during transit in the GIT. The apparatus and model present the ability to understand the kinetics and mechanisms of dissolution, supersaturation and nucleation. To support this hypothesis, analytical methods including high pressure liquid chromatography (HPLC) with ultraviolet (UV) detection were developed and fully validated. In parallel, a novel plasma membrane treatment was established to fabricate biomimetic membranes that possessed a hydrophilic and hydrophobic surface. The treated membranes are comprised of applied surface chemistries that emulate the unstirred aqueous layer created by microvilli protruding from the intestinal epithelial membrane as well as lipophilic constituents corresponding to the epithelial lipid membrane. Calculated in vitro similarity (f2) and difference (f1) factors support the hypotheses that plasma treated microporous polymer membranes exhibit biorelevant properties and demonstrate adequate biorelevance for in vitro dissolution studies. The described dissolution methodology has been applied as a tool for selection of candidates to move forward to pharmacokinetic studies. In a culminating study, in vitro – in vivo correlations (IVIVC) were performed employing the universal membrane-permeation non-sink dissolution method for formulations of Carbamazepine. To demonstrate the utility of the methodology, multiple level C correlations were established. The membrane-permeation model enables quantitative assessment of drug dissolution and absorption and offers a means to predict the relative in vivo performance of amorphous solid dispersions for BCS class II drug substances. / Chemistry