A detailed, fundamental understanding of the surface properties of molecular crystals and their interaction with adsorbing molecules (e.g. excipients) is important for tailoring the stability of formulations and the bioavailability of Active Pharmaceutical Ingredient (APIs). Few fundamental experimental studies with surface sensitive probes have been carried out for organic molecular crystals. X-ray photoelectron spectroscopy (XPS) is an established surface analysis method in the fields of adsorption, catalysis and surface chemistry of inorganic crystals. It has high surface sensitivity, probing approximately the top 1-3 nm of a crystal, and allows surface elemental analysis combined with the determination of the chemical state of the elements. To explore the possibilities and limitations of XPS for the surface characterisation of molecular crystal systems, investigation has been made on a range of paracetamol systems, three different poloxamers and blends of paracetamol with poloxamer 188. It was found by investigations of a range of polycrystalline paracetamol forms that the C1s, N1s and O1s core level emissions from the amide group of paracetamol allow to quantify, for the first time, the influence of surface contamination and adsorbed species on the paracetamol XPS data. Results of quantitative XPS analyses must be critically evaluated taking the material and energy-specific escape depth of the photoelectron signals into account. Analysis of the polycrystalline powder samples, including two different polymorphs and various partially amorphous forms of paracetamol, indicated that the core-level shifts associated with varying intermolecular interactions do not perturb the local electronic structure variations in paracetamol enough to become detectable through chemical shifts in the core level photoemission spectra. Subsequently, large, high quality single crystals of the monoclinic form I (with facet diameters between ~5 and ~10 mm) were obtained from different solvents (methanol, ethanol, acetone) to examine the influence of the crystallisation medium on the surface properties. Small spot XPS analysis was performed in several areas across facets to examine the possible influence of roughness and other lateral inhomogeneities. Careful curve-fitting of all results reveals only minor variations in the XPS data as a function of facet orientation, crystallisation medium or degree of crystallinity. Moreover, results indicate that any variations seen in XPS data very likely stem from low-level surface contamination, which is very difficult to avoid, even in a clean-room laboratory environment. In fact, the results indicate that the level of surface contamination depends significantly on the crystallisation apparatus cleanliness. Even minute concentrations of surface active components in the solutions, i.e. below the detection level of techniques for routine analytical methods, are likely to cause significant surface concentrations on crystal facets emersed from the solutions. The study thus highlights the paramount importance of microscopic surface cleanliness when assessing macroscopic facet-specific phenomena such as contact angles. Finally, XPS was employed to analyse milled and physical mixtures of paracetamol with poloxamer 188 at different percent. At minimum mass percentages poloxamer 188 adsorbs on the paracetamol surfaces; in the presence of poloxamer 188 excess the conformation of adsorbed poloxamer on the paracetamol surface changes. Studies of radiation damage on the poloxamer samples were performed both for several pure polxamers as well as for milled mixtures with paracetamol. They allowed the proposal of radiation-induced degradation mechanisms.

Subcutaneous (SC) injection is a safe and effective way to administrate monoclonal antibodies (mAbs) and very often valued by patients and healthcare providers alike. A SC injection offers noteworthy advantages over intravenous (IV) injections, such as lowering hospital and clinical costs. Additionally, SC injections requires a lower number administration and allows for self-administrated or caregiver-supported dosing at home, thus a reduced healthcare resource utilization and healthcare provider time. In recent years biotherapeutics have been one of the fastest growing class of drugs in the pharmaceutical industry due to effective therapeutics with target specificity and potency. Biopharmaceuticals are usually administrated through IV, intramuscular (IM) or SC injection. However, patients are not administrated drugs, they are administrated formulations containing a drug. It is also important to recognize that biopharmaceuticals that are meant for SC injection are usually formulated at an acidic (4-6) pH, which can be attained by using a variety of excipients and stabilising agents. Excipients such as sugar, salt and surfactant are commonly found in biopharmaceuticals and can be used to attain a multi-year shelf life. Additionally, biopharmaceuticals can form aggregates and this occurrence happens due to loss of a stabilizing excipient. Hence the importance of understanding how and why different excipients are or can be used in a formulation.

No description available.

Cette étude est dédiée à la compréhension du processus de granulation humide en mélangeurs à haut taux de cisaillement. Une étude systémique et méthodologique a été menée permettant l'investigation de l'influence des paramètres opératoires, de la technologie employée et des propriétés physico-chimiques des matières premières. Cette investigation est réalisé a travers des techniques de caractérisation morphologiques, rhéologiques et mécaniques. En reliant les courbes de couple enregistrés lors de la granulation humide à la cinétique de croissance des granules, aux caractérisations microscopiques et aux propriétés mécaniques des granules la prédiction du comportement lors de la granulation devient possible. La caractérisation des propriétés mécaniques des granules a été étudié à deux échelles: à l'échelle du milieu humide la consistance a été caractérisé par un rheometre à torque et à l'échelle de l'agglomérat sec la résistance mécanique a été caractérisé par des mesures de compression directe des grains individuelles. Cette approche permet d'avoir des informations complémentaires permettant de mieux décrire l'évolution des courbes de couple dépendantes de propriétés de la masse humide et la compétition entre les forces interfaciales et visqueuses conditionnant la qualité des grains secs résultés. Les paramètres investigués par cette approche sont l'effet du taux de remplissage du réacteur, l'effet de la vitesse d'agitation, de la présence et de la conception de l'émotteur, de la conception du réacteur employé, des propriétés physico-chimiques de la solution liante et des propriétés des mélanges binaires des poudres hydro-solubles / hydro-insolubles. / This study is dedicated to the understanding of the wet granulation process in high shear mixers. A systematic study has been carried out that allows the investigation of the influence of operating conditions, technology and physico-chemical properties of the starting materials. This investigation is achieved by morphological, rheological and mechanical characterization methods. By linking recorded torque curves during the granulation process to granule growth kinetics, microscope characterizations and to the end-granule properties granulation outcome prediction becomes possible. The characterization of the mechanical properties has been done at two scales: at the granule bed scale the bulk wet mass consistency has been determined on a mixer torque rheometer, at the granule scale single dry granule direct compression tests were carried out. This approach gives complementary information allowing better description of the torque curves directly related to the wet mass properties and the competition between static and viscous forces conditioning the dry end granule quality. The factors investigated in this study are: the effect of fill ratio, impeller speed, chopper presence and design, mixer design, binder physico-chemical properties and formulation properties for binary water-soluble / water insoluble powder mixtures.

Neste trabalho foram avaliados o comportamento do ácido gálico e de adjuvantes tecnológicos frequentemente empregados em formas farmacêuticas sólida, e das suas misturas físicas, através de métodos termoanalíticos e por espectroscopia de infravermelho. Foi investigada também a influência da compactação sobre as misturas físicas equiponderais. Os adjuvantes avaliados foram amidoglicolato de sódio, celulose microcristalina, croscarmelose sódica, crospovidona, dióxido de silício coloidal, estearato de magnésio e polimetacrilato. O ácido gálico apresentou um comportamento térmico diferenciado nas misturas, assumindo, provavelmente, uma forma instável com menor ponto de fusão. Os resultados obtidos por DSC demonstraram interação de natureza física com mudança de entalpia para misturas do ácido gálico com celulose microcristalina, crospovidona, estearato de magnésio e polimetacrilato. A interação não pode ser confirmada por espectroscopia de infravermelho para a crospovidona e polimetacrilato, devido à sobreposição das bandas com o ácido gálico. Os demais adjuvantes também apresentaram interação física, porém, sem alteração da entalpia, confirmada por espectroscopia de infravermelho, relacionada ao estabelecimento de ligações de hidrogênio entre os componentes da mistura. A compactação demonstrou particular influência sobre a interação com celulose microcristalina, croscarmelose sódica e crospovidona. / In this work were evaluated the behavior of the gallic acid and technological excipients used in sold dosage forms and their physical powder mixtures, by Differential Scanning Calorimetry (DSC) and Thermogravimety (TGA) and infrared spectroscopy (IR). The influence of the compression force on the 1:1 (w/w) physical mixtures was also investigated. The excipients evaluated were sodium starch glycolate, microcrystalline cellulose, croscarmellose sodium, crospovidone, colloidal silicon dioxide, magnesium stearate and polymethacrylate. Gallic acid presented a different thermal behavior in the mixtures, assuming, probably, an unstable form with a lower melting point. The results obtained by (DSC) demonstrated the occurrence of physical interactions with enthalpy changes for the mixtures of gallic acid with microcrystalline cellulose, crospovidone, magnesium stearate and polymethacrylate. The interaction could not be confirmed by infrared spectroscopy for crospovidone and polymethacrylate, due to overlapping of the gallic acid IR bands. The other excipients also presented physical interaction, however, without alteration of the enthalpy, confirmed by IR, which could be correlated to the establishment of hydrogen bonds between the components of the mixture. The compression of the powder mixtures demonstrated a particular influence of the interaction of gallic acid with microcrystalline cellulose, croscarmellose sodium and crospovidone.

Neste trabalho foram avaliados o comportamento do ácido gálico e de adjuvantes tecnológicos frequentemente empregados em formas farmacêuticas sólida, e das suas misturas físicas, através de métodos termoanalíticos e por espectroscopia de infravermelho. Foi investigada também a influência da compactação sobre as misturas físicas equiponderais. Os adjuvantes avaliados foram amidoglicolato de sódio, celulose microcristalina, croscarmelose sódica, crospovidona, dióxido de silício coloidal, estearato de magnésio e polimetacrilato. O ácido gálico apresentou um comportamento térmico diferenciado nas misturas, assumindo, provavelmente, uma forma instável com menor ponto de fusão. Os resultados obtidos por DSC demonstraram interação de natureza física com mudança de entalpia para misturas do ácido gálico com celulose microcristalina, crospovidona, estearato de magnésio e polimetacrilato. A interação não pode ser confirmada por espectroscopia de infravermelho para a crospovidona e polimetacrilato, devido à sobreposição das bandas com o ácido gálico. Os demais adjuvantes também apresentaram interação física, porém, sem alteração da entalpia, confirmada por espectroscopia de infravermelho, relacionada ao estabelecimento de ligações de hidrogênio entre os componentes da mistura. A compactação demonstrou particular influência sobre a interação com celulose microcristalina, croscarmelose sódica e crospovidona. / In this work were evaluated the behavior of the gallic acid and technological excipients used in sold dosage forms and their physical powder mixtures, by Differential Scanning Calorimetry (DSC) and Thermogravimety (TGA) and infrared spectroscopy (IR). The influence of the compression force on the 1:1 (w/w) physical mixtures was also investigated. The excipients evaluated were sodium starch glycolate, microcrystalline cellulose, croscarmellose sodium, crospovidone, colloidal silicon dioxide, magnesium stearate and polymethacrylate. Gallic acid presented a different thermal behavior in the mixtures, assuming, probably, an unstable form with a lower melting point. The results obtained by (DSC) demonstrated the occurrence of physical interactions with enthalpy changes for the mixtures of gallic acid with microcrystalline cellulose, crospovidone, magnesium stearate and polymethacrylate. The interaction could not be confirmed by infrared spectroscopy for crospovidone and polymethacrylate, due to overlapping of the gallic acid IR bands. The other excipients also presented physical interaction, however, without alteration of the enthalpy, confirmed by IR, which could be correlated to the establishment of hydrogen bonds between the components of the mixture. The compression of the powder mixtures demonstrated a particular influence of the interaction of gallic acid with microcrystalline cellulose, croscarmellose sodium and crospovidone.

La demande actuelle croissante d’excipients multifonctionnels par les laboratoires pharmaceutiques, amène les fabricants de matières premières à développer de nouveaux matériaux pouvant répondre à ces critères de performance. Parmi les différents procédés disponibles pour de telles productions, les techniques de co-traitement sont les plus sollicitées. Considérant l’évaluation de la fonctionnalité de différents excipients désintégrants, l’objectif de cette thèse a été de développer un tel excipient, original, économiquement intéressant et pouvant être utilisé dans la fabrication de comprimés par compression directe.Dans ce travail, nous nous sommes tout d’abord intéressés à étudier et à comparer la fonctionnalité de différents désintégrants commerciaux, en évaluant notamment l’influence des milieux réactionnels sur cette fonctionnalité.La chitine, deuxième polysaccharide naturel le plus abondant au monde, et présentant des propriétés physico-chimiques et pharmacotechniques pertinentes, a retenu notre intérêt. Un mélange co-processé, de chitine et de carbonate de calcium (CC) a été développée, et sa préparation optimisée afin de pouvoir disposer d’un matériau aux propriétés maîtrisées. Par des études conduites sur simulateur de compression, nous avons pu, d’une part, établir un profil complet de compression du CC, d’autre part, évaluer ses performances en compression directe en le formulant avec des proportions variables de composants actifs pharmaceutiques retenus comme traceurs modèles. Des études de stabilité ont enfin été réalisées, afin de déterminer ses meilleures conditions d’utilisation.Les résultats les plus marquants ont montré que la chitine présente une comprimabilité satisfaisante et des propriétés de désintégration qui ne sont pas influencées par l’environnement physico-chimique de la formulation. L’excipient co-processé CC a révélé des propriétés très intéressantes et notamment, une densité vraie et une coulabilité améliorées, par rapport à la chitine seule. Ses propriétés désintégrantes sont également particulièrement notables (comprises entre 2 et 5 s.). Son comportement en compression est par ailleurs très satisfaisant avec, une comprimabilité, une compressibilité et une compactibilité performantes; il est également à noter, que dans nos conditions de formulations, il n’a pas nécessité l'addition de lubrifiant. Les comprimés élaborés avec les composants actifs modèles ont fourni des profils de compression également performants et des aptitudes à la désintégration très satisfaisantes. Quant aux profils de dissolution pharmaceutique, ils ont révélé que, avec une teneur en CC égale à 30% m/m, la libération des actifs était rapide. Les études de stabilité conduites afin de définir les conditions optimales de conservation, ont montré que des précautions de température et d'humidité doivent être prises pour les produits formulés avec CC.L’excipient CC co-traité développé dans cette Etude présente toutes les caractéristiques d’un excellent excipient multifonctionnel (diluant, désintégrant, liant). Valorisant l’usage d’une matière première de base naturelle et très abondante (la chitine), facile à produire et économiquement rentable, il devrait pouvoir trouver un intérêt dans la formulation et la production de comprimés à dissolution rapide par compression directe. / Nowadays, there is an increasing demand for multifunctional excipients that replaces the need and use of multiple excipients. Pharmaceutical excipients coprocessing techniques represent important methods for new excipients development with enhanced functionalities. The objective of this thesis is to develop a cost-effective multifunctional excipient (filler-disintegrant-binder) used in tablet manufacturing by direct compression.In this thesis, we’ve studied and compared disintegrants functionality for different materials and evaluated the effect of media on their disintegrant’s functionality. In addition, chitin was chosen as a base to develop a multifunctional excipient used in direct compression as it showed a good and promising physicochemical and pharmaceutical properties. Chitin-Calcium carbonate (CC) coprocessed excipient was developed and its production was further optimized to ensure better powder properties and functionality. In addition, CC compression profile was established by studying its compression behavior under different conditions and formulating with active pharmaceutical ingredients to determine how it affects the formulation at different percentages. Finally, stability study was carried out to determine best conditions for the excipient handling.Results showed that chitin has good tabletability and disintegration properties that were not influenced by the physicochemical environment of the formulation. CC showed an enhancement in true density and flowability (that are considered as drawbacks for raw chitin use as an excipient) and fast disintegration (2-5s). The excipient had good tabletability, compressibility, compactibility, and it doesn’t need the use of a lubricant. CC showed a good compression profile at different manufacturing conditions (multiple lubrication levels, compression speeds and dwell times) while maintaining fast disintegration. It causes rapid disintegration and dissolution when formulated with active pharmaceutical ingredients starting from 30% w/w, and its inclusion was reflected positively on tablets strength. Stability studies showed that precautions on temperature and humidity conditions would need to be taken on CC formulated products. The results showed that the excipient serves as an excellent multifunctional excipient (filler, disintegrant, binder) used for fast disintegrating tablets produced by direct compression. It represents a cost-effective product that is efficient and easily produced at pilot plant and upon scale-up.

Neste trabalho foram avaliados o comportamento do ácido gálico e de adjuvantes tecnológicos frequentemente empregados em formas farmacêuticas sólida, e das suas misturas físicas, através de métodos termoanalíticos e por espectroscopia de infravermelho. Foi investigada também a influência da compactação sobre as misturas físicas equiponderais. Os adjuvantes avaliados foram amidoglicolato de sódio, celulose microcristalina, croscarmelose sódica, crospovidona, dióxido de silício coloidal, estearato de magnésio e polimetacrilato. O ácido gálico apresentou um comportamento térmico diferenciado nas misturas, assumindo, provavelmente, uma forma instável com menor ponto de fusão. Os resultados obtidos por DSC demonstraram interação de natureza física com mudança de entalpia para misturas do ácido gálico com celulose microcristalina, crospovidona, estearato de magnésio e polimetacrilato. A interação não pode ser confirmada por espectroscopia de infravermelho para a crospovidona e polimetacrilato, devido à sobreposição das bandas com o ácido gálico. Os demais adjuvantes também apresentaram interação física, porém, sem alteração da entalpia, confirmada por espectroscopia de infravermelho, relacionada ao estabelecimento de ligações de hidrogênio entre os componentes da mistura. A compactação demonstrou particular influência sobre a interação com celulose microcristalina, croscarmelose sódica e crospovidona. / In this work were evaluated the behavior of the gallic acid and technological excipients used in sold dosage forms and their physical powder mixtures, by Differential Scanning Calorimetry (DSC) and Thermogravimety (TGA) and infrared spectroscopy (IR). The influence of the compression force on the 1:1 (w/w) physical mixtures was also investigated. The excipients evaluated were sodium starch glycolate, microcrystalline cellulose, croscarmellose sodium, crospovidone, colloidal silicon dioxide, magnesium stearate and polymethacrylate. Gallic acid presented a different thermal behavior in the mixtures, assuming, probably, an unstable form with a lower melting point. The results obtained by (DSC) demonstrated the occurrence of physical interactions with enthalpy changes for the mixtures of gallic acid with microcrystalline cellulose, crospovidone, magnesium stearate and polymethacrylate. The interaction could not be confirmed by infrared spectroscopy for crospovidone and polymethacrylate, due to overlapping of the gallic acid IR bands. The other excipients also presented physical interaction, however, without alteration of the enthalpy, confirmed by IR, which could be correlated to the establishment of hydrogen bonds between the components of the mixture. The compression of the powder mixtures demonstrated a particular influence of the interaction of gallic acid with microcrystalline cellulose, croscarmellose sodium and crospovidone.

M. Tech. Pharmaceutical Sciences / Following the discovery of an active pharmaceutical ingredient, attempts were made to improve its delivery to the site of action and thereby its effectiveness. Insulin and other therapeutic proteins are administered almost exclusively parenterally because of their poor absorption after oral administration, but this route is associated with disadvantages including pain, discomfort and lipohypertrophy at the site of injection. A suitable absorption enhancer which could effectively improve the absorption of poorly absorbable drugs from the gastrointestinal tract would contribute to the development of an effective oral drug delivery system for these drugs. One such attempt was the formulation of the active ingredient into an appropriate dosage form for a specific route of administration to improve other properties such as manufacturability, stability and bioavailability. Formulation studies led to the development of substances called excipients, which were incorporated into dosage forms, in addition to the active pharmaceutical ingredient, to improve the properties of the final product. Aloe vera gel previously showed the ability to increase the bioavailability of vitamins and to enhance the in vitro transport of a macromolecular drug across intestinal epithelial cell monolayers. However, the effect of leaf materials from aloes, indigenous to South Africa, on drug transport across intestinal epithelia has not previously been investigated. The aim of this study is to evaluate the in vitro drug transport enhancement potential of the gel and whole leaf extract of Aloe ferox, Aloe marlothii, Aloe speciosa and compare them with that of Aloe vera across Caco-2 cell monolayers, as well as across excised rat intestinal tissues.

Introdução: O ácido rosmarínico (AR) é um composto fenólico que apresenta inúmeras atividades biológicas, dentre estas, destaca-se a atividade antioxidante. Entretanto, a biodisponibilidade do AR por via oral é de apenas 0,91 a 5,0%, fator que pode estar relacionado à sua solubilidade, estabilidade em meio gastrointestinal e mecanismo de absorção. Ciclodextrinas (CDs) são excipientes farmacêuticos utilizados com o objetivo de promover a absorção oral de fármacos por propiciarem aumento de solubilidade, estabilidade química e permeação pela membrana intestinal a partir da complexação com o fármaco. Tendo em vista o desenvolvimento de uma formulação farmacêutica, estudos de compatibilidade entre a substância e excipientes se fazem necessários. Objetivo: Obter complexo do AR com CDs derivadas, avaliar a atividade antioxidante dos complexos e compatibilidade entre excipientes. Materiais e métodos: Estudo de solubilidade de fase foi realizado para se determinar estequiometria e constante de estabilidade entre o AR e duas CDs: HPβCD e MβCD. Os complexos foram obtidos por liofilização e caracterizados por métodos espectroscópicos, calorimétrico e microscópico. A atividade antioxidante foi determinada pelo método DPPH e estudo de compatibilidade entre excipientes foi realizado por método espectroscópico, calorimétrico e cromatográfico. Resultados: O AR apresentou proporção estequiométrica 2:1 AR:CD e alta constante de estabilidade. Os métodos de caracterização permitiram inferir a presença de formação de complexo de inclusão e complexo de não-inclusão, nos quais uma molécula do AR estaria interagindo com prótons internos e outra estaria interagindo com prótons externos da CD. A atividade antioxidante dos complexos foi superior à apresentada pelo AR não complexado, demonstrando a ação das CDs sobre a doação de prótons do AR e o estudo de compatibilidade de excipientes não demonstrou incompatibilidades viabilizando a obtenção de formas farmacêuticas. Conclusão: Considerando todos os resultados, pode-se inferir que complexos AR:CD podem ser uma alternativa tecnológica para superar a baixa absorção pela via oral, sem ocasionar perda na atividade antioxidante, propiciando também o desenvolvimento de formulações sólidas orais. / Introduction: Rosmarinic acid (RA) is phenolic compound which present several biological activities, among these, antioxidant is remarkable. However, oral bioavailability of RA is only 0.91 to 5.0%, a factor that may be related to its solubility, stability in gastrointestinal environment and absorption mechanism. Cyclodextrins (CDs) are pharmaceutical excipients used in oral drug absorption by promoting increased solubility, chemical stability and permeation by the intestinal membrane through complexation with the drug. In view of the development of a pharmaceutical formulation, excipients compatibility studies are also expected. Objective: To obtain RA complex with derivative CDs (HPβCD and MβCD), to evaluate the antioxidant activity of complexes and compatibility between excipients. Materials and methods: Phase-solubility study was performed to determine stoichiometry and constant between RA and CD. The complexes were obtained by lyophilization and characterized by spectroscopic, calorimetric and microscopic techniques. The antioxidant activity was determined by the DPPH method and compatibility study among excipients was performed by spectroscopic, calorimetric and chromatographic methods.