Spelling suggestions: "subject:"recipients""
31 |
Evaluation of the effects of non-medicinal ingredients on the in vitro characteristics and in vivo bioavailability of a sublingual tablet formulation of epinephrineRachid, Ousama 30 March 2010 (has links)
Objectives: To review, develop, and validate appropriate methods for quality control testing of sublingual (SL) tablets; to formulate and characterize new generations of SL tablets of epinephrine (E) for the potential first-aid treatment of anaphylaxis; and to evaluate the effects of non-medicinal ingredients (NMIs) on the in vitro characteristics and in vivo bioavailability of the formulated tablets. Methods: A custom-made apparatus and a novel method that simulates SL conditions were evaluated for dissolution testing of SL tablets. An electronic tongue (e-Tongue) was used to assess the degree of E bitterness and to demonstrate the masking effects of sweetening and/or flavoring agents. The effect of several NMIs in various properties on the in vitro characteristics of new generations of E SL tablets was evaluated. Formulations with the best in vitro characteristics, containing E 30 mg and 40 mg, were evaluated in vivo using our validated rabbit model and compared with placebo SL tablets (negative control) and E 0.3 mg intramuscular (IM) injection (positive control). Results: The novel in vitro dissolution testing resulted in accurate and reproducible data and was capable of detecting the effect of minor changes in formulations. Using the e-Tongue, E bitartrate had an extremely bitter taste which was masked to various degrees by the addition of aspartame, acesulfame potassium, and citric acid alone or in combination. Citric acid alone masked the bitter taste by >80%. The evaluation of NMIs revealed that the best formulation contained specific proportions of mannitol and coarse and fine grades of microcrystalline cellulose. Appropriate comparative testing resulted in the selection of a taste-masked E SL formulation with optimum in vitro characteristics. This formulation containing E 40 mg resulted in similar bioavailability to E 0.3 mg IM. This formulation containing E 30 mg had higher bioavailability than placebo, but lower bioavailability than E 40 mg tablets. Conclusions: Grades and proportions of NMIs carefully selected using appropriate in vitro testing resulted in successful formulations. The results of these in vitro tests enabled the development of the optimum E SL tablet formulation which was bioequivalent to the EpiPen. These tablets are potentially suitable for Phase 1 studies in humans and might transform the first-aid treatment of anaphylaxis in community settings.
|
32 |
Approches nanotechnologiques et nutraceutiques dans le traitement de la maladie d'Alzheimer /Phivilay, Alix. January 2008 (has links) (PDF)
Thèse (M.Sc.)--Université Laval, 2008. / Bibliogr.: f. [106]-126. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.
|
33 |
Protection Mechanisms of Excipients on Lactate Dehydrogenase during Freeze-Thawing and LyophilizationMi, Yanli. January 2002 (has links)
Thesis (Ph. D.)--University of Tennessee, Memphis, 2002.
|
34 |
Διερεύνηση της χρήσης λιποσωμάτων ως in vitro μοντέλο πρόγνωσης της κυτταροτοξικότητας εκδόχωνΛόη, Χρυσή 02 February 2011 (has links)
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.
|
35 |
Ácido rosmarínico : complexação com ciclodextrinas, avaliação do potencial antioxidante in vitro e estudo de compatibilidade com excipientes com vistas ao desenvolvimento de formulação sólida oralVeras, Kleyton Santos January 2017 (has links)
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.
|
36 |
Ácido rosmarínico : complexação com ciclodextrinas, avaliação do potencial antioxidante in vitro e estudo de compatibilidade com excipientes com vistas ao desenvolvimento de formulação sólida oralVeras, Kleyton Santos January 2017 (has links)
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.
|
37 |
Interfacial and material aspects of powders with relevance to pharmaceutical tableting performanceBadal Tejedor, Maria January 2017 (has links)
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>
|
38 |
Vliv různých druhů a poměrů mikrokrystalické celulosy a laktosy na fyzikální vlastnosti tabletovin a tablet. / Influence of different types and ratios of microcrystalline cellulose and lactose on physical properties of tablet blends and tablets.Machutková, Hana January 2016 (has links)
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...
|
39 |
Adhesive mixtures for dry powder inhalationLagercrantz Forss, Louise January 2021 (has links)
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.
|
40 |
The Osmotic Second Virial Coefficient as a Predictor of Protein StabilityVerma, Kusum S 09 December 2006 (has links)
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.
|
Page generated in 0.0744 seconds