The study aims to (a) enhance the solubility of a poorly soluble drug by optimization of nanocrystal formulation using the top-down approach and (b) modify the release profile of this drug, which ...exhibits a short elimination half-life, by the integration of a fast-release phase containing the optimized nanocrystals and a sustained-release phase in a compression-coated tablet. Nanocrystals of the model drug (lornoxicam; LNX) was prepared by simultaneous application of jet-milling and ball-milling techniques. Investigation of the precipitation inhibition capacity, thermal property, and interaction of different polymers with the drug revealed polyvinyl pyrrolidone K30 (PVP) as the most effective stabilizer for nanocrystals. The immediate-release layer containing the optimized nanocrystals (size of 279.5 ± 11.25 nm and polydispersity index of 0.204 ± 0.01) was then compressed on a zero-order sustained-release matrix core using different derivatives of hydroxypropyl methylcellulose (HPMC). Application of the Design of Experiment approach (DoE) was applied to optimize the formulation of tablet. Analysis of drug concentration in dog plasma by liquid chromatography-tandem mass spectrometry demonstrated an improvement in the release behavior of LNX from the optimal compression-coated tablet integrating a HPMC-based sustained release matrix core and a PVP-stabilized lornoxicam nanocrystals coating layer compared to the reference product.
A rapid and effective method using QuEChERS-based sample preparation procedure and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis has been developed and validated to determine ...progesterone in rabbit plasma. The analyte was extracted from plasma by acetonitrile with phase partitioning by a mixture of magnesium sulfate and sodium chloride. The supernatant was then directly injected into LC-MS/MS in a positive electrospray ionization mode and quantified using progesterone-d9 as the internal standard. The method linearity was in the range from 1 ng/mL (LOQ) to 200 ng/mL. Method recovery was from 86.0% to 103%, and repeatability was lower than 5.5%. The plasma sample was stable for 12 weeks stored at 18 ± 2°C. This method was applied to quantify progesterone in rabbit plasma in a pharmacokinetic study of two transdermal formulations: a reference drug and a eutectic-hydrogel system. The data indicate that the eutectic-hydrogel system’s bioavailability was 1.5 times better than that of the reference drug, and the transdermal system is a potential drug delivery system for progesterone.
N-Hydroxyethyl dithio-desethyl carbodenafil.
Display omitted
•Adulterated health supplement with dithio-desmethyl carbodenafil and an unknown compound.•Elucidation of N-hydroxyethyl dithio-desethyl ...carbodenafil by FTIR, HRMS and NMR.•Direct bonding of a hydroxyethyl group to the heterocyclic nitrogen of dithio-desethyl carbodenafil.
A new phosphodiesterase type-5 inhibitor (PDE-5i) with thiocarbonyl and thiolactam skeleton has been identified. The unknown compound has very similar properties like dithio-desmethyl carbodenafil, which was detected alongside during the screening process. It has been isolated by a semi-preparative high performance liquid chromatography tandem ultra-violet detector (HPLC-UV). The purified compound has been characterized using Fourier-transform infrared spectroscopy (FTIR), high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance spectroscopy (NMR). It is named as N-hydroxyethyl dithio-desethyl carbodenafil due to attachment of a hydroxyethyl group to the heterocyclic nitrogen of dithio-desethyl carbodenafil.
We present a general approach to planning with incomplete information in Answer Set Programming (ASP). More precisely, we consider the problems of conformant and conditional planning with sensing ...actions and assumptions. We represent planning problems using a simple formalism where logic programs describe the transition function between states, the initial states and the goal states. For solving planning problems, we use Quantified Answer Set Programming (QASP), an extension of ASP with existential and universal quantifiers over atoms that is analogous to Quantified Boolean Formulas (QBFs). We define the language of quantified logic programs and use it to represent the solutions different variants of conformant and conditional planning. On the practical side, we present a translation-based QASP solver that converts quantified logic programs into QBFs and then executes a QBF solver, and we evaluate experimentally the approach on conformant and conditional planning benchmarks.
Purpose
The study aimed firstly to determine the release behavior of the model drug (berberine chloride) from the dry coated tablets. The second objective of this study was to evaluate the exact ...location of the dry coated tablets in in vivo.
Methods
The colon targeting tablets were developed by dry powder coating technique on pan coater. The drug release behavior was determined in the three continuous mediums: pH 1.2; 7.4 and 6.8 plus pectinase. The location of the dry coated tablets in the gastrointestinal tract of human volunteers was observed through the X-ray imaging of the dry coated tablets containing the optimized radiocontrast agents.
Results
The release kinetics of berberine chloride from the dry coated tablets was mainly controlled by erosion and enzyme sensitive mechanism. The optimum dry coated tablets having the coating powders of pectin 102:HPMC K4 M (2:1) with the coating level of 200%, and the tablet core with BaSO
4
10% and iobitridol 30% as radiocontrast agents were observed in the caecum and ascending colon of human volunteers after 5–6 h of oral administration.
Conclusion
The successful development of these dosage forms is believed to have a high potential in precisely monitoring the release of highly potent drugs such as anti-inflammatory drugs in bowel diseases.
As the practical use of answer set programming (ASP) has grown with the development of efficient solvers, we expect a growing interest in extensions of ASP as their semantics stabilize and solvers ...supporting them mature. Epistemic Specifications, which adds modal operators K and M to the language of ASP, is one such extension. We call a program in this language an epistemic logic program (ELP). Solvers have thus far been practical for only the simplest ELPs due to exponential growth of the search space. We describe a solver that, at the time of its development (mid-2016), was able to solve harder problems better (e.g., without exponentially-growing memory needs w.r.t. K and M occurrences) and faster than any other known ELP solver.
In this study, a simple and inexpensive method for food analysis is discussed. The approach is based on capillary electrophoresis (CE) instruments with capacitively coupled contactless conductivity ...detection (C4D). Following the pilot deployment of in-house fabricated CE-C4D instruments in Vietnam, a number of food additives in different food matrices, including i) oxalate and citrate in instant noodles, beer and tea drinks, ii) acidulants in beverage, coffee, alcohol and vinegar samples, and iii) artificial sweeteners in jelly and drink samples, were determined using this method. Good agreement between results obtained with CE-C4D-instruments and those from the confirmation method (HPLC-PDA) was achieved.
•A simple and inexpensive approach for food control was developed.•The approach is based on CE instruments with contactless conductivity detection (C4D).•Food additives in different food matrices in Vietnam were determined.•Good agreement with the confirmation method (HPLC-PDA) was achieved.
Street food has been a typical culinary feature of many countries. These foods, mainly, meats and fish, were often fried, and grilled with varied marinade and preparation. However, foods that contain ...a lot of protein after processing at high temperatures always have many risks, including cancer risks of which heterocyclic aromatic amines (HAAs) have been one of the typical compounds. However, there is a lack of data on HAAs in low- and medium-income countries to date.
The aim was to examine the concentration of HAAs including 2-Amino-1-methyl-6-phenylimidazo4,5-bpyridine (PhIP); 2-Amino-3,8-dimethylimidazo4,5-fquinoxaline (MeIQx); and 2-Amino-9H-pyrido2,3-bindole (AαC) in cooked meat and fish samples.
Three standards including PhIP, MeIQx, AαC, and three isotopically labeled internal standards PhIP-d3, MeIQx-d3, and AαC-15N3 were purchased from Toronto Research Chemicals, Inc. (Toronto, Canada). Formic acid, HPLC-grade methanol, acetonitrile, water, sodium chloride, and magnesium sulfate were supplied by Sigma-Aldrich (St. Louis, MO, USA). We collected cooked meat and fish samples from street markets and restaurants in the area of Cau Giay district, Hanoi, Vietnam in 2020. The collected samples were prepared for LC-MS/MS analysis.
Among 23 selected samples of cooked beef, fish, chicken, and pork, we have detected PhIP(ng/g) in 9 samples (the mean 2.68, standard deviation 2.41, median 2.40, minimum 0.33, and maximum 7.19); and AαC(ng/g) in 6 samples (the mean 0.74, standard deviation 0.75, median 0.45, minimum 0.12, and maximum 1.90); and MeIQx(ng/g) was not detected in all samples. Three grilled pork samples were positive with AαC at a concentration of 0.75–1.95 ng/g. Five fish samples have been detected to contain PhIP at the concentration of mean of 3.17; the standard deviation of 1.47, and the median of 3.90 ng/g. Two fried chickens have been detected to contain PhIP at the concentration of 0.41 and 7.19 ng/g.
We detected a considerable amount of PhIP concentration in the collected fried fish and other fried meat samples and AαC in grilled and fried pork, beef, and chicken samples. The findings warrant further measuring more compounds of the HAA group and extending the number of real samples, as well as types of samples for example cooked meats, fish, fried eggs, tofu, and other cooked food receipts by regions in Vietnam.
Multi-Context Systems with Preferences Le, Tiep; Son, Tran Cao; Pontelli, Enrico
Fundamenta informaticae,
01/2018, Letnik:
158, Številka:
1-3
Journal Article
Recenzirano
This paper presents an extension of the Multi-Context Systems (MCS) framework to allow the encoding of preferences at the level of the contexts. The work is motivated by the observation that a naive ...use of preference logics at a context level in an MCS can lead to undesirable outcomes, such as inconsistency of the MCS. To address this issue, the paper introduces the notion of ranked logics, suitable for use with multiple sources of preferences, and employs them in the definition of weakly and strongly-preferred equilibria in a Multi-Context Systems with Preferences (MCSP) framework. The usefulness of MCSP is demonstrated in two applications: modeling distributed configuration problems and finding explanations for distributed abductive diagnosis problems.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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