Thèse (M.Sc.)--Université Laval, 2008. / Bibliogr.: f. [106]-126. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

Thesis (Ph. D.)--University of Tennessee, Memphis, 2002.

Σκοπός της παρούσας μελέτης είναι η εκτίμηση της συσχέτισης ανάμεσα στην κυτταροτοξικότητα και την μείωση της ακεραιότητας λιποσωμικών μεμβρανών που προκαλούνται από έκδοχα. Εάν υπάρχει, μπορεί να προταθεί η χρήση των λιποσωμάτων ως in vitro τεχνική για την εκτίμηση της κυτταρο-τοξικότητας εκδόχων. Μελετήθηκε η κυτταροτοξικότητα σε 4 κυτταρικές σειρές ( A549, PC3, MDA-MB, MCF-7 ) και η επίδραση στην ακεραιότητα λιποσωμάτων των παρακάτω εκδόχων που χρησιμοποιούνται σε σκευάσματα τοπικής χορήγησης: Labrafac Hydro, Labrafac CC, Transcutol, Cremofor, DL- Lactic acid και Capmul σε συγκεντρώσεις 1% και 10% (v/v) Για την μέτρηση της κυτταροτοξικότητας (στις 6 και 24 ώρες επώασης) χρησιμοποιήθηκε η μέθοδος του MTT (Thiazolyl Blue Tetrazolium Bromide) ενώ για την εκτίμηση της μεμβρανικής ακεραιότητας λιποσωμάτων [χρησιμοποιήθηκαν MLV (πολυστοιβαδιακά) και SUV (μικρά μονοστοιβαδιακά) λιποσώματα, με διάφορες λιπιδικές συστάσεις [PC (φωσφατιδυλοχολίνη), HPC (υδρογονωμένη φωσφατιδυλοχολίνη) και DSPC( διστεαρουλο φωσφατιδυλοχολίνη) με ή χωρίς Chol (χοληστερόλη)] μετρήθηκε η διαφυγή της εγκλωβισμένης στα λιποσώματα καλσεΐνης. Τα πειραματικά αποτελέσματα, έδειξαν ότι η επιβίωση-πολλαπλασιασμός των κυττάρων επηρεάζεται λιγότερο ή περισσότερο από τα έκδοχα: Labrafac Hydro (1% και 10%), Transcutol (10%), Cremofor (1% και 10%), Capmul (1% και 10%) και Lactic acid (1% και 10%) ενώ πολύ λιγότερο από τα έκδοχα Labrafac CC(1% και 10%) καθώς και από το Transcutol 1%. Σε ότι αναφορά την ακεραιότητα των λιποσωμάτων ( έως 24 ώρες επώασης) τα έκδοχα Cremofor, Labrafac, Capmul, Lactic acid και Labrafac hydro επηρεάζουν όλες τις λιπιδικές συστάσεις και τύπους λιποσωμάτων που μελετήθηκαν, ενώ τα έκδοχα Transcutol και Labrafac CC επηρεάζουν πολύ λιγότερο τις πιο ρευστές λιπιδικές μεμβράνες, και σχεδόν καθόλου τις σκληρές. Φαίνεται ότι είναι πιθανή η συσχέτιση των δύο σειρών αποτελεσμάτων. / The aim of this thesis is to study if a correlation may exist between the cytotoxicity of excipients and their effect on the integrity of liposomal membranes. If such a correlation exists perhaps the effect on liposome integrity may be used as an in vitro system to predict excipient cytotoxicity. Methods: The cell toxicity in four cell lines ( A549, PC3, MDA-MB, MCF-7 ) and the influence on liposome integrity of several commonly used excipients was studied. The following excipients which are used in topical formulations were studied: Labrafac Hydro, Labrafac CC, Transcutol, Cremofor, DL- Lactic acid and Capmul at concentrations of 1% and 10% (v/v). For the measurement of cell toxicity (6 and 24 hours of incubation) the MTT-assay (Thiazolyl Blue Tetrazolium Bromide) was used, whereas for the evaluation of the liposome membrane integrity MLV (MultiLaminar Vesicles) and SUV (Small Unilaminar Vesicles) liposomes with different lipid compositions [PC (phosphatidyl choline), HPC (hydrogenated phospatidyl choline) and DSPC (distearoylphosphatidylcholine) with or without Chol (cholesterol)] were prepared and the escape of the calcein encapsulated in the liposomes was measured at different time points during their incubation in presence of the excipients. Results: The experimental results showed that the cell survival-proliferation is influenced more or less by the following excipients (in increasing effect order): Labrafac Hydro (1% and 10%), Transcutol (10%), Cremofor (1% and 10%), Capmul (1% and 10%) and Lactic acid (1% and 10%) while the effect of Labrafac CC(1% and 10%) as well as Transcutol 1%, is minimal. As far as the integrity of the liposomes (up to 24 hours of incubation) is concerned, the excipients Cremofor, Labrafac, Capmul, Lactic acid and Labrafac hydro affect all the lipidic compositions and types of liposomes that were studied, whereas the excipients Transcutol and Labrafac CC influenced only minimally the more liquid membranes and had no effect on the more rigid lipid compositions. It seems that a correlation between the two series of results is possible.

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.

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.

Tablets are the most common forms of drug administration. They are convenient to administer and easy to manufacture. However, problems associated with the adhesion of the powders to the tableting tools are common. This phenomenon is known as sticking and even though it has been well documented and studied, it remains poorly understood. The many factors that contribute to good performance of the powders make the sticking problem difficult to solve. The goal of this study is to establish a relationship between the properties measured at the nanoscale to the overall tablet mechanical properties, tablet performance and powder pre-processing induced modifications. By using atomic force microscopy (AFM) we aim to develop an analytical method to characterize the mechanical and adhesive properties of the pharmaceutical powders at the nanoscale. Other methodologies such as scanning electron microscopy (SEM), thermal analyses (DSC, TGA) and tablet strength test were also used. The materials used in this study are commonly used excipients, a sticky drug and magnesium stearate (MgSt). Two different approaches offered by AFM were employed: sharp tip imaging and colloidal probe force measurements. Nano-mechanical properties of the materials were evaluated with a sharp tip cantilever showing that higher adhesion correlates with higher tablet cohesion and that both are significantly affected by the presence of MgSt. AFM characterization of the particle surface mechanical properties at the nanoscale was also used to detect the crystallinity and amorphicity levels of the materials. New approaches to presenting such data considering the particle heterogeneity and to track the dynamics of surface recrystallization are revealed. Adhesive interactions between a steel sphere and sticky and non-sticky powders were performed with the colloidal probe technique. Sticky materials presented a higher adhesion against the steel surface, and reveal the mechanism of stickiness. This work thus contributes to the provision of predictability of the performance of formulations at an early stage of the development process. / <p>QC 20170315</p>

1 Abstract Charles University in Prague, Faculty of Pharmacy in Hradci Králové Department of: Departmanet of Pharmaceutical technology Consultant: doc. PharmDr. Zdeňka Šklubalová Ph.D. Student: Hana Machutková Title of Thesis: Influence of different types and ratios of microcrystalline cellulose and lactose on physical properties of tablet blends and tablets. In this study, the properties of tablet blends prepared from five different kinds of microcrystalline cellulose (Avicel ® A-101, 102, 105, 112, 200) and three types of lactose in different proportions were evaluated. Moisture content, the bulk and tapped density and the angle of repose were compared for tablet blends. The addition of lactose to the mixtures caused the decrease in the moisture content in the tablet blends. After evaluating the flow properties, the mixtures with suitable characteristics were compacted at compression forces of 8 and 12 kN. The force required to eject the tablet, the table strength, the disintegration time and the friability of the resulting tablets were estimated. The worst compressibility was identified for mixtures with higher concentration of Avicel 105. Due to its very small and fine particles (approximately 20μm) the filling of matrix was not uniform making tablet compression unsuccessful and thus the of uniform...

When it comes to dry powder inhalation (DPI), adhesive mixtures are the most widely used formulation type. Various techniques have been developed to generate inhaled drug particles and improve the delivery efficiency of DPI formulations. For dry powder inhaler formulations (DPIs), micronized drug powders are usually mixed with lactose carriers to improve powder handling during manufacturing and powder aerosol delivery during patient use. The performance of DPI systems is strongly dependent on several formulation factors, the construction of the delivery device and the inhalation technique. There is a growing interest in DPI in new medical areas such as vaccines and antibiotics which requires further development and challenges to ensure physical and aerosolization stability of DPI.  This project aims to discuss the development of inhalation therapy, the challenges during formulation processes, the mixing process and the use of excipients in pulmonary drug delivery in DPIs. Further, the project is covered by experiments based on the literature overview and performed at the Department of Pharmaceutical Biosciences at Uppsala University. Bulk density was measured on three series of adhesive mixtures with increasing amounts of fine particles. In two series, small amounts of Magnesium Stearate, 0,1% and 0,01% were added.

The number of protein containing therapeutic drugs is growing day by day. Lack of proper storage conditions can cause protein degradation or aggregation. The osmotic second virial coefficient, B22, is a thermodynamic parameter, which can predict protein interaction with other proteins and solvent molecules. B22 has been successfully used as predictor of crystallization conditions for a protein in the solution, and in this study an attempt has been made to relate B22 as a predictor of stability of the protein. Static light scattering was used to measure B22 in our studies. B22 and the solubility of three proteins were measured in several excipient solutions. George et al. in 1997 related the osmotic second virial coefficient with the solubility of protein in a solution. In this study we have attempted to relate solubility with B22 and stability of lysozyme, human serum albumin, and ovalbumin in buffer solutions containing various excipients.

Many companies, including Strike Pharma, are developing biologicals for individualized immunotherapeutic cancer treatments. The possibility to combine a bispecific antibody with a myriad of endogenous antigenic peptides opens the doors for highly personalized therapies. Setting up and using analytical assays is key to evaluate aggregation and overcome aggregation patterns of biologicals during CMC development. The aim of this project was to assess size exclusion chromatography (SEC) as an analytical method and subsequently evaluate several drug formulations that could be suitable for subcutaneous administration of a peptide and antibody conjugate mix. The formulations were based on a 25 mM histidine buffer pH 6.0, that had been optimized for the antibody alone, with different additives. By utilizing SEC coupled to UV-detection at 280 nm, aggregates were detected and quantified. The most effective excipients were dimethyl sulfoxide, polyethylene glycol 400 and arginine. Two different peptide-tags were compared and the pTag9mer-mut2 variant was more favorable than pTag9mer-mut1 in limiting aggregate formation with highest success rates at 1.5 mg/mL protein concentrations and the fulfillment of the high molecular weight ≤ 5% criterion. Combining antibody and peptide containing pTag9mer-mut1 in a pH 9.0 histidine buffer with added arginine engendered the least aggregates compared to any pH 6.0 formulation. However, the instability of the antibody in pH 9.0 and the risk of deamidation makes this less suitable. Future considerations include changing the administration method or using pump injection strategy, which allows higher injection volumes to limit aggregation by lowering protein concentrations.