Context: Benznidazole (BNZ) is an antiparasitic with trypanocidal properties for the etiological treatment of Chagas disease since 1973. Monitoring the stability of this drug is one of the most effective methods of assessment, forecasting and prevention of problems related to quality product.
Objective: To investigate the direct and indirect photodegradation of BNZ and to evaluate the interference of the excipients used in the forms dosage solid as well as to shed light on the chemical structure of the degradation products obtained.
Materials and methods: To perform this work we adopted the “ICH Harmonised Tripartite Guideline: Photostability Testing of New Drug Substances and Products Q1B” (Guideline Q1B). We used benzonidazole (BNZ) (N-benzil-2-(2-nitroimidazol-1-il) acetamide) (LAFEPE®, Recife, Brazil) and various excipients; beyond high-performance liquid chromatography (HPLC), differential scanning calorimetry (DSC), infrared spectroscopy (IR) and mass spectrometry/mass spectrometry (MS/MS). The indirect photodegradation of BNZ was carried out using physical mixtures with 13 pharmaceutical excipients commonly used in the preparation of solid dosage forms.
Results: HPLC and MS/MS techniques were selected for the identification of two photoproducts (PPs) and photoreactions found in direct and indirect tests with the microcrystalline cellulose, considered a critical excipient.
Discussion: Despite variations in the infrared spectrometry, differential scanning calorimetry and differential thermogravimetry curves, these techniques are not conclusive since the study of photodegradation of the drug caused decay of 30%, according to the ICH.
Conclusions: The results show that BNZ only undergoes direct photodegradation, since no new PPs were found for a combination of the drug and excipients. 相似文献
Ultra high-performance liquid chromatography-electrospray ionization-mass spectrometry (UHPLC/ESI/MS) methodology was adapted for identification and quantification of tocopherols and tocotrienols in vegetable oils with no derivatization or sample preparation steps. The UHPLC analysis was performed using a C18 column and mobile phase composed of methanol: water: ammonium hydroxide (99:1:0.1 v/v/v) and isopropanol. A single mass spectrometer with electrospray on negative mode was used as a detector for tocopherols and tocotrienols. The samples were diluted in isopropanol. The limit of quantification for tocopherols was 0.006 μg mL?1, and the linear range was 0.006 to 0.01 μg mL?1; for tocotrienols, the limit of quantification was 0.002 μg mL?1, and the linear range of analysis was 0.002 to 0.003 μg mL?1. The correlation coefficients were higher than 0.99, indicating that the method has suitable linearity. The methodology has proven to be precise, reproducible, and robust for the parameters studied. 相似文献
Monoglyceride (MG)-based oleogelation is an effective strategy to create soft matter structures with the functionality of fats, but with a nutritional profile similar to edible oils. MG oleogels are mainly studied to replace or reduce trans and saturated fats as well as to develop novel products with improved physical and organoleptic properties. The process consists of direct dispersion of MGs into the oil at temperatures above the melting point. This is followed by a cooling period in which the gelator network is formed, entrapping the oil in a crystalline structure. MG composition and concentration, oil type, process temperatures, stirring speed, shear rate during cooling, and storage time play a role in the kinetics of MG crystallization within an MG–oil system, which leads to the formation of lipid materials with different properties. A deep understanding of MG oleogelation processing parameters allows for the tailoring of oleogel properties to meet desirable characteristics as solid fat replacers. This review provides insight regarding manipulating physical process parameters to engineer structures with specific functionality. Furthermore, ultrasound technologies and optimization methodologies are discussed as tools for the production of oleogels with specific properties based on their potential use as well as the development of bi- and multi-gelators oleogels using MGs. Finally, the food applications in which MG oleogels have been tested are summarized in addition to the identified gaps that require further research. 相似文献
The effect of kefir concentration on the quality of porous white bread has been investigated. Quality evaluation was done
using flatbed scanning (FBS) for measuring crumb porosity, instrumental texture profile analysis (TPA), crust and crumb color
(L*a*b*), moisture, specific volume, and density determination techniques. The correlations between porosity, brightness, and firmness
were also investigated. Long fermentation time of the sourdough changed significantly (p<0.05) the cell mean area (mm2), cell mean perimeter (mm), firmness (N), chewiness (N), light reflectance, and specific volume (ml/g). A strong correlation
was found between microstructure of porous white bread, brightness (L), and firmness from TPA test. Kefir prolonged the shelf
life of bread. 相似文献
Alport syndrome (AS) is the second most common cause of inherited chronic kidney disease. This disorder is caused by genetic variants on COL4A3, COL4A4 and COL4A5 genes. These genes encode the proteins that constitute collagen type IV of the glomerular basement membrane (GBM). The heterodimer COL4A3A4A5 constitutes the majority of the GBM, and it is essential for the normal function of the glomerular filtration barrier (GFB). Alterations in any of collagen type IV constituents cause disruption of the GMB structure, allowing leakage of red blood cells and albumin into the urine, and compromise the architecture of the GFB, inducing inflammation and fibrosis, thus resulting in kidney damage and loss of renal function. The advances in DNA sequencing technologies, such as next-generation sequencing, allow an accurate diagnose of AS. Due to the important risk of the development of progressive kidney disease in AS patients, which can be delayed or possibly prevented by timely initiation of therapy, an early diagnosis of this condition is mandatory. Conventional biomarkers such as albuminuria and serum creatinine increase relatively late in AS. A panel of biomarkers that might detect early renal damage, monitor therapy, and reflect the prognosis would have special interest in clinical practice. The aim of this systematic review is to summarize the biomarkers of renal damage in AS as described in the literature. We found that urinary Podocin and Vascular Endothelial Growth Factor A are important markers of podocyte injury. Urinary Epidermal Growth Factor has been related to tubular damage, interstitial fibrosis and rapid progression of the disease. Inflammatory markers such as Transforming Growth Factor Beta 1, High Motility Group Box 1 and Urinary Monocyte Chemoattractant Protein- 1 are also increased in AS and indicate a higher risk of kidney disease progression. Studies suggest that miRNA-21 is elevated when renal damage occurs. Novel techniques, such as proteomics and microRNAs, are promising. 相似文献
Cotton is the most important crop for fiber production worldwide. However, the cotton boll weevil (CBW) is an insect pest that causes significant economic losses in infested areas. Current control methods are costly, inefficient, and environmentally hazardous. Herein, we generated transgenic cotton lines expressing double-stranded RNA (dsRNA) molecules to trigger RNA interference-mediated gene silencing in CBW. Thus, we targeted three essential genes coding for chitin synthase 2, vitellogenin, and ecdysis-triggering hormone receptor. The stability of expressed dsRNAs was improved by designing a structured RNA based on a viroid genome architecture. We transformed cotton embryos by inserting a promoter-driven expression cassette that overexpressed the dsRNA into flower buds. The transgenic cotton plants were characterized, and positive PCR transformed events were detected with an average heritability of 80%. Expression of dsRNAs was confirmed in floral buds by RT-qPCR, and the T1 cotton plant generation was challenged with fertilized CBW females. After 30 days, data showed high mortality (around 70%) in oviposited yolks. In adult insects fed on transgenic lines, chitin synthase II and vitellogenin showed reduced expression in larvae and adults, respectively. Developmental delays and abnormalities were also observed in these individuals. Our data remark on the potential of transgenic cotton based on a viroid-structured dsRNA to control CBW. 相似文献