52 research outputs found
In vitro biopharmaceutic evaluation of capsules containing fluconazole
Atualmente, no mercado brasileiro, vários laboratórios farmacêuticos comercializam produtos a base do antifúngico fluconazol na forma de cápsulas de 150 mg. Pretendeu-se, neste trabalho, realizar avaliação biofarmacêutica in vitro de três formulações do mercado nacional contendo fluconazol, designadas por produtos A, B e C. Após desenvolvimento e padronização do método de dissolução, avaliou-se a cinética de dissolução de cápsulas de fluconazol provenientes de dois lotes de cada produto por meio dos parâmetros k (constante de velocidade de dissolução e t85% (tempo necessário para dissolução de 85% do fármaco presente na forma farmacêutica), derivados dos perfis de dissolução. Obteve-se k s de 0,1377 min-1 e 0,1079 min-1 para os lotes de A, 0,5421min-1 para os lotes de B e 0,0354 min-1 e 0,0146 min-1 para os lotes de C. t85% foi de 15,09 min e 20,06 min para os lotes de A, 5,64 min e 6,02 min para os lotes de B e 132,12 min e 56,05 min para os lotes de C. Concluiu-se que a dissolução de fluconazol em cápsulas segue cinética de primeira ordem para os três produtos avaliados, sendo que o produto B apresenta maior velocidade de dissolução do fármaco, seguido pelo produto A e pelo produto C.Many brazilian pharmaceutical industries manufacture capsules containing 150 mg of the antifungal agent fluconazole. The present study was designed to perform a in vitro biopharmaceutical evaluation of three commercial products available in Brazil, designated as products A, B and C. After a dissolution method was developed and standardized, the dissolution kinetics for samples of two batches of each product was analysed through k s (dissolution rate constant) and t85% (time for dissolution of 85% of the drug in the dosage form), obtained from dissolution profiles. Results showed k s values of 0,1377 min-1 and 0,1079 min-1 for the tested batches of A, 0,5421min-1 for the tested batches of B and 0,0354 min-1 and 0,0146 min-1 for the tested batches of C. t85% was 15,09 min e 20,06 min for the tested batches of A, 5,64 min and 6,02 min for the tested batches of B and 132,12 min and 56,05 min for the tested batches of C. It was concluded that the dissolution of fluconazole in capsules follows first order kinetics for the three products and product B shows the greatest dissolution rate, followed by products A and C
Dissolution efficiency and bioequivalence study using urine data from healthy volunteers: a comparison between two tablet formulations of cephalexin
;O objetivo do presente estudo foi avaliar a bioequivalência de duas formulações de cefalexina disponíveis no mercado brasileiro (produto A como formulação referência e produto B como formulação teste). A eficiência de dissolução (DE%) foi calculada para ambas as formulações para avaliar suas características biofarmacêuticas. O estudo de bioequivalência oral foi realizado em vinte e quatro voluntários sadios utilizando um desenho cruzado. Uma dose oral única (comprimido contendo 500 mg de cefalexina) de cada produto foi administrada com um período de ;washout; de duas semanas. Concentrações urinárias de cefalexina foram mensuradas por método de cromatografia líquida de alta eficiência (CLAE) e os parâmetros farmacocinéticos foram estimados por dados de excreção urinária. A bioequivalência foi determinada pelos seguintes parâmetros: quantidade acumulada da cefalexina excretada na urina, quantidade total da cefalexina excretada na urina e a taxa de excreção máxima da cefalexina. Os valores de DE dos comprimidos de liberação imediata de cefalexina (500 mg) foram 68,69±4,18% para o produto A e de 71,03±6,63% para o produto B. Com relação ao teste de dissolução das duas marcas analisadas (A e B), ambas apresentaram-se de acordo com as especificações farmacopéicas, uma vez que a dissolução de ambas formulações foi superior a 80% da quantidade declarada após 45 minutos de teste (A=92,09%±1,84; B=92,84% ±1,08). Os resultados obtidos indicaram que os produtos A e B são equivalentes farmacêuticos. Os intervalos de confiança para os parâmetros farmacocinéticos estavam de acordo com os padrões internacionais, demonstrando que os produtos A e B podem ser considerados bioequivalentes e, portanto, intercambiáveis.;;The aim of the present study was to assess the bioequivalence of two cephalexin tablet formulations available in the Brazilian market (product A as reference formulation and product B as test formulation). Dissolution efficiency (DE%) was calculated for both formulations to evaluate their;in vitro;biopharmaceutical features. The oral bioequivalence study was performed in twenty-four healthy volunteers in a crossover design. Single oral dose (tablet containing 500 mg of cephalexin) of each product was administered with two weeks of washout period. Urinary concentrations of cephalexin were measured by high-performance liquid chromatography (HPLC) method and pharmacokinetics parameters were estimated by urinary excretion data. The bioequivalence was determined by the following parameters: the cumulative amount of cephalexin excreted in the urine, the total amount of cephalexin excreted in the urine and the maximum urinary excretion rate of cephalexin. DE values of immediate-release cephalexin tablets (500 mg) were 68.69±4.18% for product A and 71.03±6.63% for product B. Regarding the dissolution test of the two brands (A and B) analysed, both were in compliance with the official pharmacopeial specifications, since the dissolution of both formulations was superior to 80% of the amount declared in the label after 45 minutes of test (A=92.09%±1.84; B=92.84%±1.08). The results obtained indicated that the products A and B are pharmaceutical equivalents. Confidence intervals for the pharmacokinetic parameters were in compliance with the international standards, indicating that products A and B can be considered bioequivalents and, therefore, interchangeable.
A myriad of miRNA variants in control and Huntington's disease brain regions detected by massively parallel sequencing
Huntington disease (HD) is a neurodegenerative disorder that predominantly affects neurons of the forebrain. We have applied the Illumina massively parallel sequencing to deeply analyze the small RNA populations of two different forebrain areas, the frontal cortex (FC) and the striatum (ST) of healthy individuals and individuals with HD. More than 80% of the small-RNAs were annotated as microRNAs (miRNAs) in all samples. Deep sequencing revealed length and sequence heterogeneity (IsomiRs) for the vast majority of miRNAs. Around 80-90% of the miRNAs presented modifications in the 3'-terminus mainly in the form of trimming and/or as nucleotide addition variants, while the 5'-terminus of the miRNAs was specially protected from changes. Expression profiling showed strong miRNA and isomiR expression deregulation in HD, most being common to both FC and ST. The analysis of the upstream regulatory regions in co-regulated miRNAs suggests a role for RE1-Silencing Transcription Factor (REST) and P53 in miRNAs downregulation in HD. The putative targets of deregulated miRNAs and seed-region IsomiRs strongly suggest that their altered expression contributes to the aberrant gene expression in HD. Our results show that miRNA variability is a ubiquitous phenomenon in the adult human brain, which may influence gene expression in physiological and pathological conditions
Limbic-Predominant Age-Related TDP-43 Encephalopathy Differs from Frontotemporal Lobar Degeneration
TAR-DNA binding protein-43 (TDP-43) proteinopathy is seen in multiple brain diseases. A standardized terminology was recommended recently for common age-related TDP-43 proteinopathy: limbic-predominant, age-related TDP-43 encephalopathy (LATE) and the underlying neuropathological changes, LATE-NC. LATE-NC may be co-morbid with Alzheimer’s disease neuropathological changes (ADNC). However, there currently are ill-defined diagnostic classification issues among LATE-NC, ADNC, and frontotemporal lobar degeneration with TDP-43 (FTLD-TDP). A practical challenge is that different autopsy cohorts are composed of disparate groups of research volunteers: hospital- and clinic-based cohorts are enriched for FTLD-TDP cases, whereas community-based cohorts have more LATE-NC cases. Neuropathological methods also differ across laboratories. Here, we combined both cases and neuropathologists’ diagnoses from two research centres—University of Pennsylvania and University of Kentucky. The study was designed to compare neuropathological findings between FTLD-TDP and pathologically severe LATE-NC. First, cases were selected from the University of Pennsylvania with pathological diagnoses of either FTLD-TDP (n = 33) or severe LATE-NC (mostly stage 3) with co-morbid ADNC (n = 30). Sections from these University of Pennsylvania cases were cut from amygdala, anterior cingulate, superior/mid-temporal, and middle frontal gyrus. These sections were stained for phospho-TDP-43 immunohistochemically and evaluated independently by two University of Kentucky neuropathologists blinded to case data. A simple set of criteria hypothesized to differentiate FTLD-TDP from LATE-NC was generated based on density of TDP-43 immunoreactive neuronal cytoplasmic inclusions in the neocortical regions. Criteria-based sensitivity and specificity of differentiating severe LATE-NC from FTLD-TDP cases with blind evaluation was ∼90%. Another proposed neuropathological feature related to TDP-43 proteinopathy in aged individuals is ‘Alpha’ versus ‘Beta’ in amygdala. Alpha and Beta status was diagnosed by neuropathologists from both universities (n = 5 raters). There was poor inter-rater reliability of Alpha/Beta classification (mean κ = 0.31). We next tested a separate cohort of cases from University of Kentucky with either FTLD-TDP (n = 8) or with relatively ‘pure’ severe LATE-NC (lacking intermediate or severe ADNC; n = 14). The simple criteria were applied by neuropathologists blinded to the prior diagnoses at University of Pennsylvania. Again, the criteria for differentiating LATE-NC from FTLD-TDP was effective, with sensitivity and specificity ∼90%. If more representative cases from each cohort (including less severe TDP-43 proteinopathy) had been included, the overall accuracy for identifying LATE-NC was estimated at \u3e 98% for both cohorts. Also across both cohorts, cases with FTLD-TDP died younger than those with LATE-NC (P \u3c 0.0001). We conclude that in most cases, severe LATE-NC and FTLD-TDP can be differentiated by applying simple neuropathological criteria
Functional and structural findings of neurodegeneration in early stages of diabetic retinopathy:cross-sectional analyses of baseline data of the EUROCONDOR project
Cross-sectional study evaluating the relationship between: a) functional and structural measurements of neurodegeneration in initial stages of diabetic retinopathy (DR); and b) presence of neurodegeneration and early microvascular impairment. We analyzed baseline data of patients with type 2 diabetes (n=449) enrolled in the EUROCONDOR study (NCT01726075). Functional studies by multifocal ERG (mfERG) evaluated neurodysfunction and structural measurements using spectral domain optical-coherence tomography (SD-OCT) evaluated neurodegeneration. The mfERG P1 amplitude was more sensitive than the P1 implicit time (IT), and was lower in patients with ETDRS 20-35 than in patients with ETDRS <20 (p=0.005). In 58% of cases, mfERG abnormalities were present in the absence of visible retinopathy. Correspondence between SD-OCT thinning and mfERG abnormalities was shown in 67% of the eyes with ETDRS <20 and in 83% of the eyes with ETDRS 20-35. Notably, 32% of patients with ETDRS 20-35 presented no abnormalities in mfERG or SD-OCT. We conclude that there is a link between mfERG and SD-OCT measurements which increases with the presence of microvascular impairment. However, in our particular study population (ETDRS ≤ 35) a significant proportion of patients had normal GC-IPL thickness and normal mfERG findings. We raise the hypothesis that neurodegeneration may play a role in the pathogenesis of DR in many, but not in all type 2 diabetic patients
Population-based multicase-control study in common tumors in Spain (MCC-Spain): rationale and study design
Introduction: We present the protocol of a large population-based case-control study of 5 common tumors
in Spain (MCC-Spain) that evaluates environmental exposures and genetic factors.
Methods: Between 2008-2013, 10,183 persons aged 20-85 years were enrolled in 23 hospitals and primary
care centres in 12 Spanish provinces including 1,115 cases of a new diagnosis of prostate cancer,
1,750 of breast cancer, 2,171 of colorectal cancer, 492 of gastro-oesophageal cancer, 554 cases of chronic
lymphocytic leukaemia (CLL) and 4,101 population-based controls matched by frequency to cases by age,
sex and region of residence. Participation rates ranged from 57% (stomach cancer) to 87% (CLL cases) and
from 30% to 77% in controls. Participants completed a face-to-face computerized interview on sociodemographic
factors, environmental exposures, occupation, medication, lifestyle, and personal and family
medical history. In addition, participants completed a self-administered food-frequency questionnaire
and telephone interviews. Blood samples were collected from 76% of participants while saliva samples
were collected in CLL cases and participants refusing blood extractions. Clinical information was recorded
for cases and paraffin blocks and/or fresh tumor samples are available in most collaborating hospitals.
Genotyping was done through an exome array enriched with genetic markers in specific pathways. Multiple
analyses are planned to assess the association of environmental, personal and genetic risk factors
for each tumor and to identify pleiotropic effects.
Discussion: This study, conducted within the Spanish Consortium for Biomedical Research in Epidemiology
& Public Health (CIBERESP), is a unique initiative to evaluate etiological factors for common cancers
and will promote cancer research and prevention in Spain.The study was partially funded by the “Accion Transversal
del Cancer”, approved on the Spanish Ministry Council on the
11th October 2007, by the Instituto de Salud Carlos III-FEDER
(PI08/1770, PI08/0533, PI08/1359, PS09/00773, PS09/01286,
PS09/01903, PS09/02078, PS09/01662, PI11/01403, PI11/01889,
PI11/00226, PI11/01810, PI11/02213, PI12/00488, PI12/00265,
PI12/01270, PI12/00715, PI12/00150), by the Fundación Marqués
de Valdecilla (API 10/09), by the ICGC International Cancer Genome
Consortium CLL, by the Junta de Castilla y León (LE22A10-2), by
the Consejería de Salud of the Junta de Andalucía (PI-0571), by the
Conselleria de Sanitat of the Generalitat Valenciana (AP 061/10),
by the Recercaixa (2010ACUP 00310), by the Regional Government
of the Basque Country by European Commission grants FOOD-CT-
2006-036224-HIWATE, by the Spanish Association Against Cancer
(AECC) Scientific Foundation, by the The Catalan Government
DURSI grant 2009SGR1489
Avaliação biofarmacêutica in vitro de cápsulas de fluconazol In vitro biopharmaceutic evaluation of capsules containing fluconazole
Atualmente, no mercado brasileiro, vários laboratórios farmacêuticos comercializam produtos a base do antifúngico fluconazol na forma de cápsulas de 150 mg. Pretendeu-se, neste trabalho, realizar avaliação biofarmacêutica in vitro de três formulações do mercado nacional contendo fluconazol, designadas por produtos A, B e C. Após desenvolvimento e padronização do método de dissolução, avaliou-se a cinética de dissolução de cápsulas de fluconazol provenientes de dois lotes de cada produto por meio dos parâmetros k (constante de velocidade de dissolução e t85% (tempo necessário para dissolução de 85% do fármaco presente na forma farmacêutica), derivados dos perfis de dissolução. Obteve-se k s de 0,1377 min-1 e 0,1079 min-1 para os lotes de A, 0,5421min-1 para os lotes de B e 0,0354 min-1 e 0,0146 min-1 para os lotes de C. t85% foi de 15,09 min e 20,06 min para os lotes de A, 5,64 min e 6,02 min para os lotes de B e 132,12 min e 56,05 min para os lotes de C. Concluiu-se que a dissolução de fluconazol em cápsulas segue cinética de primeira ordem para os três produtos avaliados, sendo que o produto B apresenta maior velocidade de dissolução do fármaco, seguido pelo produto A e pelo produto C.<br>Many brazilian pharmaceutical industries manufacture capsules containing 150 mg of the antifungal agent fluconazole. The present study was designed to perform a in vitro biopharmaceutical evaluation of three commercial products available in Brazil, designated as products A, B and C. After a dissolution method was developed and standardized, the dissolution kinetics for samples of two batches of each product was analysed through k s (dissolution rate constant) and t85% (time for dissolution of 85% of the drug in the dosage form), obtained from dissolution profiles. Results showed k s values of 0,1377 min-1 and 0,1079 min-1 for the tested batches of A, 0,5421min-1 for the tested batches of B and 0,0354 min-1 and 0,0146 min-1 for the tested batches of C. t85% was 15,09 min e 20,06 min for the tested batches of A, 5,64 min and 6,02 min for the tested batches of B and 132,12 min and 56,05 min for the tested batches of C. It was concluded that the dissolution of fluconazole in capsules follows first order kinetics for the three products and product B shows the greatest dissolution rate, followed by products A and C
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