• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 25
  • 16
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 56
  • 31
  • 29
  • 20
  • 19
  • 15
  • 12
  • 8
  • 8
  • 8
  • 6
  • 6
  • 6
  • 6
  • 6
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

The BLM Helicase Is Involved in the Repair of DNA Lesions Induced by Diverse Genotoxins

Behbehani, Gregory Kayvhan 03 April 2007 (has links)
No description available.
42

Efeito da Hidroxiuréia, uma substância de uso médico, sobre parâmetros biológicos de Drosophila melanogaster /

Rangel, Veronica Ferreira. January 2011 (has links)
Orientador: Hermione Elly Melara de Campos Bicudo / Banca: Otávio Ricci Júnior / Banca: Cláudia Regina Bonini Domingos / Resumo: A Hidroxiuréia (HU) é utilizada como medicamento em várias doenças humanas, incluindo anemia falciforme e câncer. Basicamente, na primeira, atua aumentando a porcentagem de hemoglobina fetal, o que diminui a gravidade do quadro clínico por inibir a polimerização da hemoglobina S e, no segundo, atua impedindo a síntese de DNA na fase S, desta forma bloqueando a divisão celular. Há preocupação com o tratamento longo com essa substância por causar efeitos colaterais, um dos quais se relaciona a problemas na fertilidade masculina. A Drosophila, devido a várias características, como ser o organismo com maior homologia com o homem quanto às doenças genéticas, por utilizar esses genes homólogos nos mesmos processos, mas de forma simplificada e por expressar os genes humanos em construções transgênicas, é hoje muito utilizada em estudos de doenças humanas e de respostas a fármacos, buscando esclarecer mecanismos de ação e conseqüências do uso. Neste trabalho, foram estudados, sob o efeito da HU em duas concentrações (0,1 e 0,25mg/ml de meio de cultura), no modelo biológico mencionado, as características taxa de oviposição, produtividade (número de descendentes), tempo de desenvolvimento, mortalidade, longevidade, tempo de pré-cópula , duração da cópula, presença de alterações morfológicas externas, morfologia do aparelho reprodutor masculino, modificações do peso das moscas, morfologia dos cromossomos politênicos e padrão de expressão das enzimas esterasicas. A produtividade foi analisada em seis gerações consecutivas, visando obter maior compreensão dos efeitos da HU. Cada característica analisada envolveu uma metodologia diferente, descrita no corpo do trabalho. A análise estatística foi baseada na aplicação da ANOVA, e nas comparações de Kruskal-Wallis e Mann-Whitney. Em algumas características o efeito do tratamento mostrou-se... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Hydroxyurea (HU) is used as a medicine in several human diseases, including sickle cell disease (SCD) and cancer. Basically, in the first, HU acts by increasing the percentage of fetal hemoglobin, thus decreasing the severity of the disease symptoms due to inhibition of the hemoglobin S polymerization. In the second mentioned disease, it acts by preventing DNA synthesis in S phase, thereby blocking cell division. There is some concern about side effects caused by the long-term treatment with HU. One of them relates to problems in male fertility. Drosophila, because of its characteristics, such as being the organism with the highest homologies with man as to genetic diseases, since it uses homologous genes in these processes in a simplified form, and also by expressing human genes in transgenic constructs, is now being widely used in studies of human diseases and responses to drugs, seeking for clarifying action mechanisms and consequences of their use. In this work, we studied, in Drosophila biological characteristics under the effect of HU in two concentrations (0.1 and 0.25 mg / ml of culture medium), including oviposition rate, productivity (number of offspring), time development, mortality, longevity, pre-mating and mating duration, presence of morphological changes in external morphology and in the male reproductive system, fly weight changes, polytene chromosome morphology and patterns of esterase enzymes. Productivity was analyzed in six consecutive generations. Each feature analyzed involved a different methodology, described in the body of the work. Statistical analysis was based on the application of ANOVA, and comparisons using the Kruskal-Wallis and Mann-Whitney tests. In some characteristics, the effect of treatment was dosisdependent. In the light of numbers, productivity was higher in control experiments (C) of six generations, and among the treated ones with... (Complete abstract click electronic access below) / Mestre
43

Níveis séricos de biomarcadores de inflamação, ativação endotelial e plaquetária e imunomodulação em pacientes com doença falciforme submetidos a diferentes modalidades terapêuticas / Serum levels of biomarkers of inflammation, endothelial and platelet activation and immunomodulation in patients with sickle cell disease submitted to different therapeutic modalities

Lima, Keli Cristina de 11 October 2018 (has links)
A doença falciforme constitui um grupo de hemoglobinopatias hereditárias caracterizadas por uma mutação de ponto na cadeia da globina ?, que resulta em uma hemoglobina anormal denominada HbS. Apesar de sua importância para a saúde pública mundial e seu grande impacto social, a doença falciforme ainda apresenta muitas questões fisiopatológicas não esclarecidas e desafios terapêuticos. Paralelamente, existe a necessidade da descoberta de novos biomarcadores fisiopatológicos da doença falciforme e de biomarcadores de resposta terapêutica. O objetivo desse trabalho foi quantificar, em amostras de soro de indivíduos sadios (N=19) e de pacientes com doença falciforme sem tratamento (N=14) ou tratados com hidroxiuréia (N=15), transfusão crônica (N=15) ou transplante alogênico de células-tronco hematopoéticas (N=21), biomarcadores de ativação endotelial (VCAM-1, ICAM-1, E-selectina, P-selectina, HGF, FGF, VEGF-A, endothelina-1, CXCL4/PF4, TGF-? e óxido nítrico), biomarcadores de ativação plaquetária (von Willebrand e trombomodulina), biomarcadores de inflamação (IL-1?, pentraxina-3, IL-18, IL-6, IL-8, IL-2, IL-17A, TNF-?, INF-?, CCL2/MCP-1, CCL4/MIP-1?, IL-12p70, IL-33, IL-27, GM-CSF, CD163, osteopontina, BAFF, APRIL e heme) e biomarcadores relacionados à imunomodulação (arginase-1 e IL-10). De acordo com os resultados obtidos e as análises de correlação, os pacientes com doença falciforme sem tratamento, tratados com transfusão crônica ou transplante apresentaram perfis mais inflamatórios que os pacientes tratados com hidroxiuréia. Os tratamentos com transfusão crônica e transplante não foram capazes de diminuir os níveis séricos dos biomarcadores de inflamação, de ativação endotelial e plaquetária para níveis similares aos dos indivíduos sadios. Os pacientes tratados com transfusão crônica apresentaram o perfil mais inflamatório de todos os grupos analisados. Apesar dos pacientes tratados com hidroxiuréia apresentarem os menores níveis séricos de biomarcadores de inflamação e de ativação endotelial e plaquetária, estes continuaram apresentando níveis séricos elevados de heme e da citocina pró-inflamatória IL-18. Os pacientes transplantados apresentaram perfil inflamatório intenso, com níveis elevados de P-selectina, trombomodulina e IL-8 (relacionados à ativação endotelial, ativação plaquetária e inflamação, respectivamente) em comparação com todos os grupos analisados. Porém, os pacientes transplantados apresentaram níveis séricos de IL-18 significativamente menores que os pacientes com doença falciforme sem tratamento. Os pacientes transplantados apresentaram níveis séricos da citocina anti-inflamatória IL-10 similares aos de indivíduos sadios, porém, significativamente maiores que os pacientes tratados com hidroxiuréia. Os resultados obtidos nesse trabalho podem direcionar estudos futuros para o monitoramento laboratorial de respostas terapêuticas aos diferentes tratamentos atualmente utilizados para doença falciforme e para o desenvolvimento de novos tratamentos ou de terapias complementares às que estão atualmente disponíveis. / Sickle cell disease is a group of hereditary hemoglobinopathies characterized by a point mutation in the ? globin chain, which results in an abnormal hemoglobin named HbS. Despite its importance for global public health and its great social impact, sickle cell disease still presents many unclarified pathophysiological issues and therapeutic challenges. In parallel, there is a need for the discovery of new pathophysiological biomarkers of sickle diseases and biomarkers of therapeutic response. The aim of this study was to quantify serum samples from healthy subjects (N = 19) and patients with sickle cell disease (N = 14) or treated with hydroxyurea (N = 15), chronic transfusion (N = 15) or allogeneic hematopoietic stem cell transplantation (N = 21) endothelial activation biomarkers (VCAM-1, ICAM-1, E-selectin, P-selectin, HGF, FGF, VEGF-A, endothelin-1, CXCL4 / PF4, TGF-? and nitric oxide), platelet activation biomarkers (von Willebrand and thrombomodulin), inflammatory biomarkers (IL-1?, pentraxin-3, IL-18, IL-6, IL-8, IL-2, IL-17A, TNF-?, INF-?, CCL2/MCP-1, CCL4/MIP-1?, IL-12p70, IL-33, IL-27, GM-CSF, CD163, osteopontin, BAFF, APRIL and heme) and immunomodulatory biomarkers (arginase-1 and IL-10). According to the obtained results and correlation analyzes, patients with sickle disease without treatment, treated with chronic transfusion or transplantation presented more high inflammatory profiles than patients treated with hydroxyurea. Patients treated with chronic transfusion and transplantation were not able to decrease the elevated serum biomarkers of inflammation and endothelial and platelet activation similar to healthy subjects levels. Patients treated with chronic transfusion presented the most inflammatory profile of all groups analyzed. Although patients treated with hydroxyurea had the lowest serum levels of inflammatory and endothelial/platelet activation biomarkers, they continued to have high serum levels of heme and proinflammatory cytokine IL-18. Transplanted patients presented a high inflammatory profile, with elevated levels of P-selectin, thrombomodulin and IL-8 (related to endothelial activation, platelet activation and inflammation, respectively) compared to all groups analyzed. However, transplant patients had significantly lower serum IL-18 levels than patients with untreated sickle cell disease. Notably, transplanted patients had levels of the anti-inflammatory cytokine IL-10 similar to those of healthy subjects, but significantly higher than patients treated with hydroxyurea. The results obtained in this study may pave the way for future studies for the laboratory monitoring of therapeutic responses to different sickle cell disease treatments and for the development of new or complementary treatments to the currently available therapies.
44

Adaptation of dosing regimen of chemotherapies based on pharmacodynamic models

Paule, Inès 29 September 2011 (has links) (PDF)
There is high variability in response to cancer chemotherapies among patients. Its sources are diverse: genetic, physiologic, comorbidities, concomitant medications, environment, compliance, etc. As the therapeutic window of anticancer drugs is usually narrow, such variability may have serious consequences: severe (even life-threatening) toxicities or lack of therapeutic effect. Therefore, various approaches to individually tailor treatments and dosing regimens have been developed: a priori (based on genetic information, body size, drug elimination functions, etc.) and a posteriori (that is using information of measurements of drug exposure and/or effects). Mixed-effects modelling of pharmacokinetics and pharmacodynamics (PK-PD), combined with Bayesian maximum a posteriori probability estimation of individual effects, is the method of choice for a posteriori adjustments of dosing regimens. In this thesis, a novel approach to adjust the doses on the basis of predictions, given by a model for ordered categorical observations of toxicity, was developed and investigated by computer simulations. More technical aspects concerning the estimation of individual parameters were analysed to determine the factors of good performance of the method. These works were based on the example of capecitabine-induced hand-and-foot syndrome in the treatment of colorectal cancer. Moreover, a review of pharmacodynamic models for discrete data (categorical, count, time-to-event) was performed. Finally, PK-PD analyses of hydroxyurea in the treatment of sickle cell anemia were performed and used to compare different dosing regimens and determine the optimal measures for monitoring the treatment
45

Understanding the role of superoxide in mediating the teratogenicity of hydroxyurea

Larouche, Geneviève. January 2008 (has links)
Hydroxyurea is a teratogen; treatment of dams during organogenesis causes various malformations. Administration of a free radical scavenger ameliorates the embryotoxicity of hydroxyurea, suggesting that oxidative stress mediates this toxicity. The goal of this thesis was to test the hypothesis that superoxide, a reactive oxygen species, is involved. Superoxide dismutase 1 (SOD1) is an antioxidant enzyme that converts superoxide to hydrogen peroxide. To elucidate the role of superoxide in mediating hydroxyurea teratogenicity, dams that were wildtype or hemizygous for hSOD1 were treated on gestation day 9 with saline (control) or hydroxyurea (400 or 600 mg/kg). Fetal death rate and weight were affected similarly by hydroxyurea treatment in litters from wildtype and hemizygous dams. However, fetuses from hemizygote dams exposed to 600 mg/kg hydroxyurea had fewer specific external and skeletal malformations when compared to wildtype dams. These data suggest that superoxide dismutase 1 protects fetuses against specific consequences of oxidative insult during organogenesis.
46

Efeito da Hidroxiuréia, uma substância de uso médico, sobre parâmetros biológicos de Drosophila melanogaster

Rangel, Veronica Ferreira [UNESP] 12 August 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-12Bitstream added on 2014-06-13T20:54:02Z : No. of bitstreams: 1 rangel_vf_me_sjrp.pdf: 852839 bytes, checksum: 3d2eb971002011ec16f7a22fafd009c2 (MD5) / A Hidroxiuréia (HU) é utilizada como medicamento em várias doenças humanas, incluindo anemia falciforme e câncer. Basicamente, na primeira, atua aumentando a porcentagem de hemoglobina fetal, o que diminui a gravidade do quadro clínico por inibir a polimerização da hemoglobina S e, no segundo, atua impedindo a síntese de DNA na fase S, desta forma bloqueando a divisão celular. Há preocupação com o tratamento longo com essa substância por causar efeitos colaterais, um dos quais se relaciona a problemas na fertilidade masculina. A Drosophila, devido a várias características, como ser o organismo com maior homologia com o homem quanto às doenças genéticas, por utilizar esses genes homólogos nos mesmos processos, mas de forma simplificada e por expressar os genes humanos em construções transgênicas, é hoje muito utilizada em estudos de doenças humanas e de respostas a fármacos, buscando esclarecer mecanismos de ação e conseqüências do uso. Neste trabalho, foram estudados, sob o efeito da HU em duas concentrações (0,1 e 0,25mg/ml de meio de cultura), no modelo biológico mencionado, as características taxa de oviposição, produtividade (número de descendentes), tempo de desenvolvimento, mortalidade, longevidade, tempo de pré-cópula , duração da cópula, presença de alterações morfológicas externas, morfologia do aparelho reprodutor masculino, modificações do peso das moscas, morfologia dos cromossomos politênicos e padrão de expressão das enzimas esterasicas. A produtividade foi analisada em seis gerações consecutivas, visando obter maior compreensão dos efeitos da HU. Cada característica analisada envolveu uma metodologia diferente, descrita no corpo do trabalho. A análise estatística foi baseada na aplicação da ANOVA, e nas comparações de Kruskal-Wallis e Mann-Whitney. Em algumas características o efeito do tratamento mostrou-se... / Hydroxyurea (HU) is used as a medicine in several human diseases, including sickle cell disease (SCD) and cancer. Basically, in the first, HU acts by increasing the percentage of fetal hemoglobin, thus decreasing the severity of the disease symptoms due to inhibition of the hemoglobin S polymerization. In the second mentioned disease, it acts by preventing DNA synthesis in S phase, thereby blocking cell division. There is some concern about side effects caused by the long-term treatment with HU. One of them relates to problems in male fertility. Drosophila, because of its characteristics, such as being the organism with the highest homologies with man as to genetic diseases, since it uses homologous genes in these processes in a simplified form, and also by expressing human genes in transgenic constructs, is now being widely used in studies of human diseases and responses to drugs, seeking for clarifying action mechanisms and consequences of their use. In this work, we studied, in Drosophila biological characteristics under the effect of HU in two concentrations (0.1 and 0.25 mg / ml of culture medium), including oviposition rate, productivity (number of offspring), time development, mortality, longevity, pre-mating and mating duration, presence of morphological changes in external morphology and in the male reproductive system, fly weight changes, polytene chromosome morphology and patterns of esterase enzymes. Productivity was analyzed in six consecutive generations. Each feature analyzed involved a different methodology, described in the body of the work. Statistical analysis was based on the application of ANOVA, and comparisons using the Kruskal-Wallis and Mann-Whitney tests. In some characteristics, the effect of treatment was dosisdependent. In the light of numbers, productivity was higher in control experiments (C) of six generations, and among the treated ones with... (Complete abstract click electronic access below)
47

Increasing Hydroxyurea Adherence for Pediatric Patients With Sickle Cell Anemia

Reed, Caroline 01 January 2016 (has links)
Sickle cell disease is a disabling chronic autosomal recessive blood disease characterized by abnormal hemoglobin, pain crises, and frequent emergency department visits. Adherence to hydroxyurea therapy has been shown to improve these patient outcomes. Guided by the theory of comfort, the purpose of this project was to determine if an educational intervention would increase adherence to hydroxyurea therapy in pediatric patients between 2 and 17 years of age recruited from an urban university hospital hematology clinic. The RE-AIM model was used to support the translation of evidence and the change process. An educational video produced by AFLAC was viewed by patients' parents 4 weeks after enrollment into this pretest/posttest design project. A total of 22 African-American parent participants completed the 8-item Morisky Medication Adherence Scale at baseline and again at 8 weeks to assess hydroxyurea adherence. The Short Test of Functional Health Literacy in Adults tool was used to assess parents' health learning needs; all parents met the adequate literacy level at baseline. Using t test statistics, no statistically significant differences were found pretest to posttest on the Morisky Medication Adherence Scale scores, mean corpuscular hemoglobin, and fetal hemoglobin percentages. Wilcoxon Signed Rank tests showed no significant differences in emergency room visits nor number of pain crisis. Although no significant changes emerged in short-term hematologic findings, emergency room visits, and pain crises, social change in the health care setting was promoted by confirming parents were able to understand education and a high level of hydroxyurea adherence was maintained; literature indicated that long-term adherence to hydroxyurea limits severe attacks.
48

Identification of New Metabolic Mutations in the Fission Yeast Schizosaccharomyces pombe that Sensitize the Cell to Hydroxyurea

Mahdi, Alaa 17 December 2020 (has links)
No description available.
49

Understanding the role of superoxide in mediating the teratogenicity of hydroxyurea

Larouche, Geneviève. January 2008 (has links)
No description available.
50

Développement et évaluation de la stabilité de formulations pharmaceutiques destinées à la population pédiatrique

Coache, Daphné 03 1900 (has links)
Le manque de produits pharmaceutiques destinés à la population pédiatrique est un problème auquel sont confrontés les professionnels de la santé. Les pharmaciens doivent fréquemment se tourner vers les médicaments destinés aux adultes afin de fournir aux jeunes patients les traitements adéquats. L’utilisation de préparations magistrales pour adapter les médicaments homologués aux besoins de la population pédiatrique reste, encore à ce jour, l’option la plus souvent utilisée. Dans ce mémoire, nous proposons le développement et l’évaluation de nouvelles formulations pharmaceutiques destinées à la population pédiatrique afin de bonifier les options thérapeutiques mises à la disposition des professionnels de la santé. De plus, nous avons exploré l’utilisation de nouvelles techniques spécialisées pour surmonter des défis analytiques rencontrés, ultimement dans le but de déterminer en toute confiance la stabilité et la sécurité de ces nouvelles formulations. La première étude visait à évaluer la stabilité de préparations magistrales de chlorhydrate de clonidine (20 µg/mL) préparées avec des comprimés dans le véhicule commercial Ora-Blend. Les formulations embouteillées ont été conservées à 25°C/60% RH pendant 90 jours. Les défis analytiques rencontrés lors de l’analyse de la stabilité chimique ont été surmontés par l’implémentation d'une nouvelle méthode d'extraction en phase solide, ayant permis d’optimiser la quantification du chlorhydrate de clonidine, se retrouvant qu’en très faible quantité dans les formulations orales. L'absence d'instabilités physiques, évaluée par des mesures qualitatives et quantitatives, et l’absence d'instabilités chimiques, mise en évidence par une méthode HPLC-UV indicatrice de stabilité, confirment qu’accorder une date de péremption de 90 jours à ces préparations magistrales serait approprié. La deuxième étude portait sur l’évaluation de la stabilité de préparations magistrales d’hydroxyurée (100 mg/mL) dans l’Ora-Blend. Dans le cadre de cette étude, différentes méthodes de préparation (mortier, mélangeur, QuartetRx) et différentes sources de principe actifs (poudre, contenu des capsules, capsules entières) ont été étudiées. Toutes les formulations ont été conservées à 25°C pendant 90 jours dans des bouteilles et 14 jours dans des seringues orales. Le développement d'une méthode HPLC indicatrice de stabilité impliquant la dérivation de l’hydroxyurée par le xanthydrol aura permis la rétention l’hydroxyurée sur une colonne à phase inverse de type C18. Plus de 90.0 % de la concentration initiale d’hydroxyurée a été conservé tout au long de l’étude, et ce, pour toutes les conditions testées. L’évaluation visuelle des préparations n’a révélé aucun changement au cours de l’étude de stabilité. Des changements de pH allant jusqu'à 1.6 unités ont toutefois été observés après 90 jours d’entreposage et ont mis en lumière une voie de dégradation de l’hydroxyurée, générant ultimement l’ion ammonium. Ce dernier a été quantifié et les concentrations mesurées, définies comme acceptables. Les résultats ont montré que toutes les formulations d’hydroxyurée étudiées sont demeurées stables jusqu’à 90 jours à 25°C. Pour terminer, une étude exploratoire ayant pour but d’évaluer des comprimés à croquer à saveur d’érable a été réalisée. Le sucre d’érable et un arôme naturel d’érable ont été ajoutés à la composition des comprimés afin d’obtenir une saveur suffisamment prononcée pour masquer le goût amer de l’acétaminophène. Une étude de stabilité préliminaire, impliquant une période de 30 jours d’entreposage dans des conditions de stabilité accélérées (40°C/75%RH), aura permis d’explorer les propriétés physico-chimiques de cette nouvelle formulation, de soulever les défis potentiels et de générer des hypothèses en lien avec l’augmentation de dureté observée après seulement 14 jours d’entreposage. Les résultats de cette étude préliminaire serviront de point de départ pour le futur développement de produits pharmaceutiques à la saveur du Québec. Les techniques utilisées et les études réalisées dans le cadre de ce projet de maîtrise auront permis de générer des résultats robustes qui pourront être utilisés par les professionnels de la santé. Ces informations seront pertinentes à la pratique pharmaceutique et permettront d’offrir à la population pédiatrique des nouvelles options de traitement sécuritaires et efficaces. / The lack of pharmaceuticals intended to the pediatric population is an issue facing healthcare professionals. Pharmacists must frequently resort to adult treatments to provide adequate treatment to young patients. The use of compounding to adapt commercial drugs to the needs of the pediatric population is still, to this day, the most considered option. In this master’s thesis, we propose the development and evaluation of new medicinal preparations for pediatrics in order to improve and diversify the therapeutic options available to healthcare professionals. In addition, we have explored the use of new specialized techniques to overcome analytical challenges encountered, with the goal of confidently determining the stability and safety of these new formulations. The first study aimed to assess the stability of compound preparations of clonidine hydrochloride (20 µg / mL) prepared with tablets in the commercial vehicle Ora-Blend. Bottled formulations were stored at 25°C/60% RH for 90 days. The analytical challenges encountered during the analysis of chemical stability were overcome by the implementation of a new method of solid phase extraction, which allowed to optimize the quantification of clonidine hydrochloride, present in very small amount in oral formulations. The absence of physical instabilities, assessed by qualitative and quantitative measurements, and the absence of chemical instabilities, as demonstrated by a stability indicating HPLC-UV method, confirm that it would be appropriate to grant a 90-day expiration date to these compounded oral liquids. The second study evaluated the stability of compound preparations of hydroxyurea (100 mg / mL) in Ora-Blend. In this study, different preparation methods (mortar, mixer, QuartetRx) and different sources of hydroxyurea (powder, content of capsules, whole capsules) were studied. All formulations were stored at 25°C for 90 days in bottles and 14 days in oral syringes. The development of a stability indicating HPLC method involving the derivatization of hydroxyurea by xanthydrol will have enabled hydroxyurea retention on a C18 type reverse phase column. Over 90.0% of the initial hydroxyurea concentration was recovered throughout the study under all conditions tested. Visual evaluation of the preparations did not reveal any changes during the stability study. Changes in pH of up to 1.6 units were observed after 90 days of storage and revealed a degradation pathway for hydroxyurea, ultimately generating ammonium ion. The latter was quantified, and the measured concentrations defined as acceptable. The results showed that all hydroxyurea formulations studied were stable for up to 90 days at 25°C. Finally, an exploratory study to evaluate maple flavored chewable tablets was carried out. Maple sugar and a natural maple flavor have been added to the composition of the tablets to achieve a flavor strong enough to mask the bitter taste of acetaminophen. The pre-stability study, involving a period of 30 days of storage under accelerated stability conditions (40°C/75% RH), will have made it possible to explore the physicochemical properties of this new formulation, to raise the potential challenges and generate hypotheses related to the increase in hardness observed after only 14 days of storage. The results of this preliminary study will serve as a starting point for the future development of pharmaceutical products with a Quebec flavor. The techniques used and the studies performed will have generated robust results that could help healthcare professionals in their practice.

Page generated in 0.0364 seconds