Yes / Artemether (ARTM) is a very effective antimalarial drug with poor solubility and consequently low bioavailability. Smart nanocrystals of ARTM with particle size of 161±1.5 nm and polydispersity index of 0.172±0.01 were produced in <1 hour using a wet milling technology, Dena® DM-100. The crystallinity of the processed ARTM was confirmed using differential scanning calorimetry and powder X-ray diffraction. The saturation solubility of the ARTM nanocrystals was substantially increased to 900 µg/mL compared to the raw ARTM in water (145.0±2.3 µg/mL) and stabilizer solution (300.0±2.0 µg/mL). The physical stability studies conducted for 90 days demonstrated that nanocrystals stored at 2°C-8°C and 25°C were very stable compared to the samples stored at 40°C. The nanocrystals were also shown to be stable when processed at acidic pH (2.0). The solubility and dissolution rate of ARTM nanocrystals were significantly increased (P<0.05) compared to those of its bulk powder form. The results of in vitro studies showed significant antimalarial effect (P<0.05) against Plasmodium falciparum and Plasmodium vivax. The IC50 (median lethal oral dose) value of ARTM nanocrystals was 28- and 54-fold lower than the IC50 value of unprocessed drug and 13- and 21-fold lower than the IC50 value of the marketed tablets, respectively. In addition, ARTM nanocrystals at the same dose (2 mg/kg) showed significantly (P<0.05) higher reduction in percent parasitemia (89%) against P. vivax compared to the unprocessed (27%), marketed tablets (45%), and microsuspension (60%). The acute toxicity study demonstrated that the LD50 value of ARTM nanocrystals is between 1,500 mg/kg and 2,000 mg/kg when given orally. This study demonstrated that the wet milling technology (Dena® DM-100) can produce smart nanocrystals of ARTM with enhanced antimalarial activities.

A leucemia mielóide crônica (LMC) é uma doença cujo marcador molecular é o rearranjo gênico BCR/ABL, original da translocação t(9;22), conhecida como cromossomo Philadelphia. Recentemente, os inibidores da enzima tirosina-quinase têm sido estudados e utilizados para o tratamento da LMC. Nesta classe, está o Mesilato de Imatinibe, uma pequena molécula que inibe competitivamente a BCR/ABL tirosina quinase, impedindo sua atividade. Por não possuir monografia publicada em compêndios oficiais, o objetivo deste trabalho foi avaliar o perfil in vitro de dissolução de comprimidos de mesilato em diferentes condições. A quantificação do fármaco foi feita utilizando a cromatografia líquida de alta eficiência em fase reversa (CLAE-FR) e as análises foram realizadas em uma coluna C18 Gemini Phenomenex®, utilizando como fase móvel tampão acetato de sódio 10,7 mmol/L, pH 3,0:metanol (40:60 v/v). O método foi validado e apresentou-se linear no intervalo de concentração de 10-150 µg/mL (r=0,9993). Os coeficientes de variação obtidos foram inferiores a 2,0 % e a exatidão próxima de 100 %. Também foram avaliados os parâmetros seletividade, robustez, estabilidade e limite de quantificação (10 µg/mL). A avaliação do perfil in vitro de dissolução foi realizada em três diferentes meios de dissolução (HCl 0,1 N, tampão acetato de sódio pH 4,5 e tampão fosfato de potássio monobásico pH 6,8), três velocidades de agitação (50, 75 e 100 rpm) e dois tipos de aparatos (pá e cesta). Os resultados obtidos neste teste indicaram que a forma farmacêutica em estudo é de liberação imediata, uma vez que foi verificada liberação de grande quantidade do fármaco em um curto período de tempo. A comparação dos perfis de dissolução, realizada através do cálculo da eficiência de dissolução, apresentou diferenças em relação à porcentagem do fármaco liberado. a condição mais adequada para avaliar o perfil in vitro de dissolução é o meio de dissolução HCl 0,1 N, aparato da pá e velocidade de agitação de 75 ou 100 rpm. / Chronic myeloid leukemia (CML) is a disease whose molecular marker is the BCR/ABL, original of the translocation t (9; 22), known as the Philadelphia chromosome. Recently, inhibitors of the enzyme tyrosine kinase have been studied and used for the treatment of CML. In this class, is the Imatinib mesylate, a small molecule that competitively inhibits BCR/ABL tyrosine kinase, preventing its activity. To do not have a monograph published in official compendia, the objective of this study was to evaluate the in vitro dissolution of tablets mesylate in different conditions. The quantification of the drug was made using high performance liquid chromatography on reversed phase (RP-HPLC) and analysis was performed on a Phenomenex® Gemini C18 column using a mobile phase of sodium acetate buffer 10.7 mmol/L pH 3.0:methanol (40:60 v/v). The method was validated and presented in a linear concentration range of 10-150 µg/mL (r=0.9993). The coefficients of variation obtained were below 2.0% and accuracy near 100%. We also evaluated the parameters selectivity, robustness, stability and limit of quantification (10 µg/mL). The evaluation of in vitro dissolution was conducted in three different dissolution media (0.1 N HCl, sodium acetate buffer pH 4.5 and potassium phosphate monobasic buffer pH 6.8), three agitation speeds (50, 75 and 100 rpm) and two types of devices (paddle and basket). The results of this tests indicated that the pharmaceutical form in question is immediate release, since it was observed release of large amounts of the drug in a short period of time. The comparison of dissolution profiles, conducted by calculating the dissolution efficiency, showed differences compared to the percentage of drug released. The best conditions to evaluate the in vitro profile of dissolution is the dissolution medium 0.1 N HCl, paddle apparatus and stirring speed of 75 or 100 rpm.

A leucemia mielóide crônica (LMC) é uma doença cujo marcador molecular é o rearranjo gênico BCR/ABL, original da translocação t(9;22), conhecida como cromossomo Philadelphia. Recentemente, os inibidores da enzima tirosina-quinase têm sido estudados e utilizados para o tratamento da LMC. Nesta classe, está o Mesilato de Imatinibe, uma pequena molécula que inibe competitivamente a BCR/ABL tirosina quinase, impedindo sua atividade. Por não possuir monografia publicada em compêndios oficiais, o objetivo deste trabalho foi avaliar o perfil in vitro de dissolução de comprimidos de mesilato em diferentes condições. A quantificação do fármaco foi feita utilizando a cromatografia líquida de alta eficiência em fase reversa (CLAE-FR) e as análises foram realizadas em uma coluna C18 Gemini Phenomenex®, utilizando como fase móvel tampão acetato de sódio 10,7 mmol/L, pH 3,0:metanol (40:60 v/v). O método foi validado e apresentou-se linear no intervalo de concentração de 10-150 µg/mL (r=0,9993). Os coeficientes de variação obtidos foram inferiores a 2,0 % e a exatidão próxima de 100 %. Também foram avaliados os parâmetros seletividade, robustez, estabilidade e limite de quantificação (10 µg/mL). A avaliação do perfil in vitro de dissolução foi realizada em três diferentes meios de dissolução (HCl 0,1 N, tampão acetato de sódio pH 4,5 e tampão fosfato de potássio monobásico pH 6,8), três velocidades de agitação (50, 75 e 100 rpm) e dois tipos de aparatos (pá e cesta). Os resultados obtidos neste teste indicaram que a forma farmacêutica em estudo é de liberação imediata, uma vez que foi verificada liberação de grande quantidade do fármaco em um curto período de tempo. A comparação dos perfis de dissolução, realizada através do cálculo da eficiência de dissolução, apresentou diferenças em relação à porcentagem do fármaco liberado. a condição mais adequada para avaliar o perfil in vitro de dissolução é o meio de dissolução HCl 0,1 N, aparato da pá e velocidade de agitação de 75 ou 100 rpm. / Chronic myeloid leukemia (CML) is a disease whose molecular marker is the BCR/ABL, original of the translocation t (9; 22), known as the Philadelphia chromosome. Recently, inhibitors of the enzyme tyrosine kinase have been studied and used for the treatment of CML. In this class, is the Imatinib mesylate, a small molecule that competitively inhibits BCR/ABL tyrosine kinase, preventing its activity. To do not have a monograph published in official compendia, the objective of this study was to evaluate the in vitro dissolution of tablets mesylate in different conditions. The quantification of the drug was made using high performance liquid chromatography on reversed phase (RP-HPLC) and analysis was performed on a Phenomenex® Gemini C18 column using a mobile phase of sodium acetate buffer 10.7 mmol/L pH 3.0:methanol (40:60 v/v). The method was validated and presented in a linear concentration range of 10-150 µg/mL (r=0.9993). The coefficients of variation obtained were below 2.0% and accuracy near 100%. We also evaluated the parameters selectivity, robustness, stability and limit of quantification (10 µg/mL). The evaluation of in vitro dissolution was conducted in three different dissolution media (0.1 N HCl, sodium acetate buffer pH 4.5 and potassium phosphate monobasic buffer pH 6.8), three agitation speeds (50, 75 and 100 rpm) and two types of devices (paddle and basket). The results of this tests indicated that the pharmaceutical form in question is immediate release, since it was observed release of large amounts of the drug in a short period of time. The comparison of dissolution profiles, conducted by calculating the dissolution efficiency, showed differences compared to the percentage of drug released. The best conditions to evaluate the in vitro profile of dissolution is the dissolution medium 0.1 N HCl, paddle apparatus and stirring speed of 75 or 100 rpm.

Este trabalho objetivou investigar o processo de revestimento/aglomeração de extratos vegetais em leito fluidizado com atomização top spray, visando melhorar a estabilidade dos compostos bioativos dos extratos e suas propriedades farmacotécnicas. Açúcar cristal, pellets de açúcar e de celulose microcristalina, grânulos de celulose microcristalina, grânulos de arroz e farinha de mandioca foram utilizados como partículas sementes. Inicialmente, avaliou-se a influência do tamanho das partículas e diferentes composições de alimentação contendo extrato vegetal de Rosmarinus officinalis (alecrim). Farinha de mandioca e pellets de açúcar de diferentes granulometrias foram empregados como partículas semente. O desempenho do processo foi avaliado através da eficiência de revestimento e porcentagem de aglomeração. Os grânulos formados foram caracterizados quanto ao tamanho, fluidez e retenção de compostos bioativos (polifenóis). As formulações estudadas também foram submetidas à secagem em spray dryer para comparação entre os produtos obtidos. Os resultados obtidos mostraram que a eficiência de revestimento/aglomeração e a porcentagem de aglomeração dependem das propriedades físico-químicas das partículas sementes e das composições alimentadas. As viscosidades das formulações contendo o extrato vegetal e suas interações com as partículas iniciais influenciaram significativamente o processo. Os grânulos formados em leito fluidizado apresentaram ótima fluidez e maior retenção de polifenóis que os produtos obtidos por spray drying. Pellets de celulose microcristalina de diferentes granulometrias foram utilizados como partículas semente para investigar a dinâmica do sistema durante a encapsulação/aglomeração em leito fluidizado, por meio de análises de sinais de flutuação de pressão associados à cinética de crescimento dos grânulos e ao desempenho do processo. Dois modos operacionais foram avaliados: o modo intermitente (com interrupção da atomização da composição de alimentação em um período específico para redução do teor de umidade no sistema) e o modo contínuo (sem interrupção da atomização de alimentação). O aumento na porcentagem de aglomeração, até certo valor durante o processo, ocasionou aumento no desvio padrão nos sinais da amplitude da flutuação de pressão enquanto o sistema permaneceu estável, indicando poucas mudanças no padrão de circulação de sólidos. Este comportamento ocorreu até que a porcentagem de aglomeração atingiu um valor capaz de ocasionar instabilidades no sistema e, assim, o aumento adicional na percentagem de aglomeração acarretou o colapso do sistema. Neste momento, o desvio padrão da amplitude da flutuação de pressão tende a diminuir, sendo este comportamento mais evidente no modo operacional contínuo e com partículas semente de menor granulometria. Mudanças no desvio padrão da amplitude dos sinais da flutuação de pressão evidenciam que este método é capaz de detectar alterações na dinâmica do sistema e pode ser uma ferramenta útil para o controle e monitoramento do processo. Ensaios para avaliação da influência de diferentes variáveis operacionais, vazão de atomização e velocidade do ar de fluidização, no desempenho do processo foram realizados em modo operacional intermitente utilizando pellets de celulose microcristalina como partículas sementes. As condições operacionais mais adequadas, com maior eficiência de revestimento e menor porcentagem de aglomeração, foram selecionadas para avaliação de duas composições de alimentação contendo extrato vegetal com diferentes agentes de encapsulação, goma Arábica e concentrado proteico de soro de leite, associados à maltodextrina, ácido esteárico e Poloxamer 407. O desempenho dos processos foi avaliado através da eficiência de revestimento e porcentagem de aglomeração e os produtos quanto à fluidez e teor de compostos bioativos do alecrim: ácido cafeico, ácido rosmarínico, carnosol e ácido carnósico, determinados por HPLC-DAD. As duas formulações mostraram-se adequadas quanto ao desempenho do processo, eficiência de revestimento maior que 70% e à retenção de compostos bioativos, eficiência de encapsulação maior que 60%. Os grânulos foram submetidos testes de estabilidade acelerada e de longa duração. Os compostos bioativos sofreram degradação durante os testes com perda total de carnosol e ácido carnósico nos grânulos obtidos com as duas formulações diferentes. Também foi realizado teste de digestão gastrointestinal in vitro com os dois produtos diferentes. As concentrações de ácidos cafeico e rosmarínico não sofreram alterações significativas no decorrer do processo, tanto na simulação das condições gástricas quanto intestinais. O carnosol e o ácido carnósico sofreram perda total ao final da fase intestinal nos dois tipos de grânulos. Os grânulos com diferentes agentes encapsulantes, foram revestidos com Opadry® II visando proporcionar maior estabilidade contra degradação dos compostos bioativos. Ocorreu maior proteção do carnosol nos grânulos contendo goma Arábica submetidos ao teste de estabilidade de longa duração, a 30 °C e 75 % UR, porém esta proteção não foi efetiva para nenhum dos grânulos submetidos ao teste de estabilidade acelerada a 40 °C. Este estudo demonstrou a viabilidade do processo de encapsulação de extratos vegetais em leito fluidizado como um método promissor para produção de composições fitoterápicas com propriedades farmacotécnicas e físico-químicas adequadas. / This work aimed to investigate coating/agglomeration process of herbal extracts in fluidized bed with top spray atomization in order to improve stability of bioactive compounds and their pharmacotechnical properties. Crystal sugar granules, sugar and microcrystalline cellulose pellets, microcrystalline cellulose, cassava flour and rice granules, were used as seed particles. First, coating/agglomeration processes with cassava flour and sugar pellets as seed particles and feed compositions loaded with herbal extract of Rosmarinus officinalis (rosemary) were investigated. Fluidized bed performance was evaluated based on coating efficiency and agglomeration percentage. Products were characterized by determining the particle sizes, flow properties and retention of bioactive compounds (polyphenols). Herbal compositions were also spray dried to compare the product generated by both processes. Results showed that coating efficiency and percentage of agglomeration depend on seed particles and feed compositions physicochemical properties. The viscosity of the feed formulations and the interaction with seed particles influenced process performance. Fluidized bed granules exhibited higher efficiency of coating/agglomeration, higher retention of bioactive compounds and better flow properties than the powder obtained by spray drying. Microcrystalline cellulose pellets of different sizes were used as seed particles to investigate system dynamic during fluidized bed encapsulation/agglomeration by analysis of pressure fluctuation signals associated with growth kinetics and process performance. Two distinct operating modes were investigated: intermittent (interrupting the composition atomization for a specific period of time in order to reduce the system humidity) and continuous (without interruption of feed atomization). The increase in the agglomeration percentage to a certain value during the processes caused an increase in the standard deviation of the amplitude of the pressure fluctuations signals while the system remained stable, indicative of slight change on solids circulation patterns. However, the standard deviation of the amplitude of the pressure fluctuations signals tended to decrease when agglomeration percentage reached a value able to affect significantly the system stability, in which agglomerates growth tended to cause the system collapse. This behavior was most evident for small size seed particles and continuous operating mode. The changes in the standard deviation of the amplitude of pressure fluctuation signals showed strong evidence that this method would be able to detect changes in system dynamics and can be a useful tool for process control and system monitoring. Different operational variables, feed flow rate and fluidizing air flow rate, were used to analyze fluidized bed performance using intermittent mode and microcrystalline cellulose pellets as seed particles. Operating conditions that promoted higher coating efficiency and lower percentage of agglomeration were selected to be used in processes to evaluated different feed compositions loaded with herbal extract and encapsulating agents of two types, Arabic gum and whey protein, associated with stearic acid and poloxamer 407. Process performance was evaluated by coating efficiency and percentage of agglomeration. Products were evaluated by flow properties and the retention of bioactive compounds: cafeic acid, rosmarinic acid, carnosol and carnosic acid, determined by HPLC-DAD. Both compositions presented high coating efficiency and retention of bioactive compounds. Products were submitted to accelerated and long-term stability tests. Bioactive compounds of all granules suffered degradation during the tests with total loss of carnosol and carnosic acid. In vitro gastrointestinal digestion assays were carried out with the two types of products obtained. The concentrations of caffeic and rosmarinic acids did not change significantly during the digestion process, both in the simulation of gastric as intestinal conditions. The carnosol and carnosic acid have undergone total loss at the end of the intestinal phase in both types of products. The two types of granules with different encapsulating agents, were coated with Opadry® II aiming to provide greater stability against degradation of bioactive compounds. Higher protection of carnosol occurred in the granules containing gum Arabic subjected to long term stability test at 30 ° C, 75% RH, but this protection was not effective for any of the granules subjected to accelerated stability testing at 40 °C. The results provide strong evidence of the feasibility of the fluidised bed as a promising method for production of encapsulated phytopharmaceutical compositions with adequate pharmacotechnical and physicochemical properties.

Ce travail de thèse a eu comme objectif la mise en place et la validation d’une méthodologie expérimentale pour le suivi de l’évolution in-vitro de substituts osseux à base de phosphates de calcium. Du phosphate dicalcique dihydraté (DCPD, CaHPO4·2H2O) et du phosphate tricalcique bêta (β-TCP, β-Ca3(PO4)2) ont été choisis comme matériaux modèles de deux grandes classes de substituts osseux: les “biosolubles” (sujets à dissolution après implantation) et les “biorésorbables” (sujets à résorption cellulaire après implantation). Pour l’étude des phénomènes de dissolution et de reprécipitation observés lorsque les phosphates de calcium sont plongés en solution, ces matériaux ont été produits sous forme d’échantillons microporeux (60% de porosité pour le DCPD, 75% pour le β-TCP) et soumis à des tests de dissolution in-vitro en conditions statiques ou dynamiques (sans ou avec renouvellement du liquide) dans différentes solutions tamponnées à pH physiologique (TRIS et PBS) et pour des durées s’étalant entre 30 minutes et 2 mois. L’analyse des propriétés physico-chimiques, microstructurales et mécaniques des échantillons avant et après immersion a permis d’évaluer l’influence du type de milieu et des conditions de test choisies sur l’évolution des échantillons. Une attention particulière a été prêtée à la caractérisation mécanique: la technique de micro-indentation instrumentée sphérique a été préférée à autres essais plus conventionnels. Cette technique permet d’évaluer plusieurs paramètres tels que la dureté et le module de Young de façon quasi non-destructive et à une échelle locale. En conséquence, l’utilisation de la micro-indentation s’est avérée d’une grande aide pour le suivi des caractéristiques d’échantillons dégradés qui présentaient un gradient de propriétés entre la surface (où le processus de dégradation commence) et le cœur (sujet à des changements sur plus long terme). La dernière partie de cette étude a été dédiée à l’étude du deuxième phénomène qui entraine la résorption de substituts osseux in-vivo, à savoir la résorption cellulaire. Pour cela des essais cellulaires avec des cellules précurseurs d’ostéoclastes ont été réalisés sur des échantillons denses de β-TCP pur ou dopé avec 5% molaire de magnésium. L’addition de cet élément est censée modifier les propriétés du matériau (notamment sa solubilité) et, par conséquence, modifier le comportement cellulaire. Les résultats des tests ont confirmé la cytocompatibilité des deux types de β-TCP, mais ont également mis en avant une difficulté d’activation des ostéoclastes. Deux des causes possibles seraient liées à la topographie de surface des échantillons et au relargage des ions calcium suite à la dissolution du matériau. / The present Ph.D. thesis work was aimed to establish and assess an experimental methodology to monitor the in-vitro evolution of calcium phosphate (CaP) bone substitutes. Dicalcium phosphate dihydrate and beta-tricalcium phosphate were chosen as model of two main classes of bone substitutes: “biosoluble” ones (which undergo dissolution after implantation) and “bioresorbable” ones (which undergo cellular resorption after implantation). In order to study the dissolution and precipitation phenomena, which take place once CaPs are immersed in solution, these materials were produced in the form of micro-porous samples (60% of porosity for DCPD, 75% for β-TCP) and used for dissolution tests in-vitro in static and dynamic conditions (without or with liquid renewal) in different buffered solutions at physiologic pH (TRIS and PBS) and for periods of time ranging between 30 minutes and 2 months. The analysis of the physico-chemical, microstructural and mechanical properties of the samples before and after immersion allowed to evaluate the influence of the chosen medium and immersion conditions on the evolution of the specimens. Particular attention was paid to the mechanical characterisation: instrumented spherical micro-indentation was preferred to other more conventional tests. This technique enables the evaluation of several parameters such as the hardness and the Young’s modulus in a quasi-non-destructive way and on a local scale. As a consequence, the use of micro-indentation proved to be of great help for monitoring the characteristics of the degraded specimens, which presented a gradient of properties between the surface (where the degradation process starts) and the core (subject to changes on a longer period). The last part of this work was focused on the study of the second main phenomenon, which takes part in the in-vivo resorption of bone substitutes, that is to say the cellular resorption. For this purpose, cellular tests with osteoclast-precursor cells were carried out on dense samples made of pure and magnesium-doped β-TCP (5 mol.% of Mg). The addition of magnesium was aimed to modify the properties of the material and, as a consequence, the cellular behavior. The results confirmed the cytocompatibility of both types of β-TCP, but they also showed a difficult activation of osteoclasts. Two of the possible causes would be linked to the topography of the surface of the specimens and to the release of calcium ions due to the dissolution of the material.

目前在國內外藥界對比對溶離資料之處理方法有很多種.在本文以常用之二維隨機集區實驗設計,共變異數分析法,單變量分裂區集變異析法,Chow(1995)所提出之時間數列分析法,及美國食品藥物管理局在1995年11月所提出的方法,比較此五種方法並以電腦模擬不同情形之資料再對其結果予以分析. / There are various ways of comparing dissolution profiles between two drug products. In this thesis, we compare five statistical methods often used,namely, two-way randomized block design, analysis of covariance, split-plot,time-series analysis method proposed by Chow (1995), and the method proposed by Food and Drug Administration (FDA) in November, 1995. The five methods are compared via simulation studies under different conditions, analyses arealso provided.

The general aim of this thesis was to evaluate a newly designed and constructed miniaturized rotating disk apparatus for in vitro dissolution rate measurements of different drug substances from all of the classes in the Biopharmaceutical Classification System (BCS). The new equipment is based on a low volume flow-through cell of Plexiglas, a gold plated magnetic bar and a special designed press. The disk of drug substance (approx. 5 mg) is placed eccentrically in the bar. Rotation speeds were set with a graded magnetic stirrer. An external HPLC pump delivered a continuous flow of aqueous medium to the flow-through cell during dissolution testing. A reversed phase high-performance liquid chromatography system using diode array detection (RP-HPLC-DAD) was coupled online to the new equipment. The injections from the miniaturized rotating disk outlet into the quantifying HPLC system were controlled by a six-position switching valve. The injection volumes from the valve and the autosampler, used for the external standards, were statistically evaluated to match each other volumetrically. No analyses were longer than three minutes, using isocratic mode. A traditional USP rotating disk apparatus was used as a reference system and the two instruments were shown to be statistically dissimilar in the numerical dissolution rate values probably due to different hydrodynamics, but had approximately the same precision/repeatability. When correlating the logarithmic values of the in vitro dissolution rate (G) with the apparent solubility (S), using shake-flask methodology in the solubility studies, the two apparatuses gave the same correlation patterns. Further correlation studies were done where the media components were altered by the use of different buffer species or additives into the buffers, such as inorganic salts. Chemometric tools, e.g. orthogonal partial least squares (OPLS), were used to better evaluate the most influential factors for G and S in different media. The most significant factor for a model basic drug substance (terfenadine) was pH, followed by the ionic strength (I) and added sodium chloride in one of the media. However, the surfactants in the Fasted State Simulated Intestinal Fluid (FaSSIF-V2) were found to be insignificant for G and S in this study (using a 95% confidence interval). The new miniaturized apparatus is a promising prototype for in vitro dissolution rate measurements both for early screening purposes and in dissolution testing during drug development, but needs further instrumental improvements.

It has always been a challenge to imitate the lung environment, therefore there is a constant development of standardized in vitro dissolution methods for inhaled products. Dissolution in vitro has been considered as an important parameter, because low solubility determines the bioavailability of inhaled drugs. The in vitro dissolution data generated by the dissolution test experiment can be correlated with in vivo pharmacokinetic data through in vitro-in vivo correlation (IVIVC), because a completed predictive IVIVC model is very useful for drug formulation design and manufacturing changes after approval. The aim of this study was to investigate the effect of the membrane on the dissolution profile of orally inhaled drugs with different solubility, Budesonide (BUD) and Fluticasone propionate (FP) in the different pore sizes of the membrane 8.0 μm, 3.0 μm and 0.4 μm. The method in this study builds on previous dissolution methods, a Transwell® setup to dissolve the drugs with a small amount of dissolution medium, which mimics more the limited lung fluid capacity in vivo. In order to collect the dose from the drugs, Andersen Cascade Impact was used. The dissolution rate of BUD was first in the ranking in all of the pore sizes in the membrane.

Today, orally inhaled drugs found on the market suffer from variable and discontinuous pulmonary drug release which lowers efficacy and patience compliance. This is usually a consequence of the poor understanding of the interaction and dissolution behavior of drug particles in the lung environment. Thus, the aim of this project was to investigate the effect of the dissolution medium on dissolution profiles for the well-known orally inhaled drug budesonide (BD) and fluticasone propionate (FP), in order to assess the importance of a proper selection of dissolution media for in vitro dissolution methods. In order to achieve this a modified Andersen Cascade Impactor was used to simulate deposition of particles onto filters. The dissolution was measured using a Transwell set up with polycarbonate membranes that can hold the filters with the deposited drug on it. Different media were prepared, from simple to more biorelevant. The samples taken during the dissolution experiments were analyzed quantitatively using UPLC-UV and the experimental data was processed by fitting to the Weibull function. The aim of this project was successfully achieved and the dissolution media that worked best for both BD and FP was PBS with the addition of 0.5% SDS. On the other hand, the dissolution media that performed the least for both BD and FP was the simulated lung fluid (SLF) with presence of 0.02% (w/v) DPPC. This may be due to the fact that DPPC forms liposomal aggregates which probably results in the media becoming more viscous and hence the dissolution time becomes slower.

Les interactions aliment-médicaments nuisant aux processus de libération et/ou à la stabilité de leurs principes actifs doivent être caractérisées en raison de leurs conséquences adverses sur la biodisponibilité orale, l’efficacité thérapeutique et, dans le cas des agents anti infectieux, la sélection d’organismes résistants. Notre étude a évalué la relation entre l'efficacité de la libération in vitro de la chlortétracycline (CTC) et de la lincomycine (LIN) dans le liquide gastrique simulé de porc (LGSP) et la capacité de rétention d'eau (CRE) d’ingrédients couramment utilisés dans l’alimentation des porcs (tourteau de soja (TS), drèche de distillerie sèche avec solubles (DDS) et farine de viande et d'os (FVO), maïs, blé, et seigle), que l’on a fortifié avec 880 ppm de CTC ou 440 ppm de LIN. La CRE des ingrédients différait significativement (p <0,0001) et était maximale avec le TS, aussi bien dans l'eau que le LGSP. Le FVO avait une CRE significativement plus basse dans le LGSP que dans l'eau (p <.0001). Les effets du temps de trempage sur la CRE étaient négligeables pour tous les ingrédients (p> 0,50). La CRE diminue avec l'augmentation de la taille des particules pour tous les aliments, mais leurs relations différaient significativement (p<0.0001). Tous les ingrédients alimentaires testés ont diminué la vitesse et l'étendue de la dissolution des prémélanges de CTC et de LIN. Le CRE était le principal facteur qui a empêché la dissolution des deux médicaments (p <0,0001), tandis que le temps et la teneur en cendres des ingredients favorisaient significativement leur dissolution (p ≤ 0,008). En comparaison des prémélanges dissouts seuls, le DDS et le seigle ont libéré 80% de ces antibiotiques, tandis que le TS, le blé et le maïs en ont libéré entre 40 et 50%. La neutralisation du LGSP au pH intestinal porcin a diminué les proportions dissoutes d’antibiotiques, mais pas significativement (p>0.69). La CRE des ingrédients utilisés dans la fabrication d'aliments médicamenteux serait donc un indicateur prometteur des interactions aliment-prémélange médicamenteux de LIN et de CTC. Afin d'augmenter leur libération et leur potentiel thérapeutique, la formulation des aliments médicamenteux pourrait être améliorée en utilisant des ingrédients alternatifs, dont la CRE est moindre. / Food-drug interactions adversely affecting the release process and the stability of their active ingredients must be characterized because of their adverse consequences on oral bioavailability, therapeutic efficacy and, in the case of antibiotics, selection resistant organisms. Our study evaluated the relationship between the efficiency of the in vitro release of chlortetracycline (CTC) and lincomycin (LIN) in simulated pig gastric fluid (SPGF) and the water-holding capacity (WHC) of feedstuffs commonly used in pig feed (soybean meal (SBM), dry distillers' grain with solubles (DDGS) and meat and bone meal (MBM), corn (gC), wheat (gW), and rye (gR), which it was fortified with 880 ppm CTC or 440 ppm LIN. The WHC of ingredients differed significantly (p <0.0001) among feedstuffs with the highest value for SBM both in water and SPGF and lowest value for MBM. The MBM had a significantly lower WHC in SPGF than in water (p <.0001). The effects of soaking time on WHC were negligible for all feedstuffs (p> 0.50). The WHC decreased with increasing particle size for all feedstuffs, but their relationships differed significantly (p <0.0001). All the tested feedstuffs decreased the rate and extent of dissolution of the CTC and LIN premixes. WHC was the main factor that hindered the dissolution of both drugs (p <0.0001), while the time and ash content of the ingredients significantly favored their dissolution (p ≤ 0.008). Compared to the dissolved premixes alone, DDGS and gR released 80% of these antibiotics, while SBM, gW and gC released between 40% and 50%. Neutralization of SPGF at swine intestinal pH decreased the dissolved proportions of antibiotics, but not significantly (p> 0.69). The WHC of the used feedstuffs in the manufacture of medicated feed would therefore be a promising indicator of the feed-drug interactions of LIN and CTC. To increase their release and therapeutic potential, the formulation of medicated feeds could be improved by using alternative ingredients, with less WHC.