Search results for "Testing"
showing 10 items of 1769 documents
In silicoprediction of drug dissolution and absorption with variation in intestinal pH for BCS class II weak acid drugs: ibuprofen and ketoprofen
2012
The FDA Biopharmaceutical Classification System guidance allows waivers for in vivo bioavailability and bioequivalence studies for immediate-release solid oral dosage forms only for BCS class I. Extensions of the in vivo biowaiver for a number of drugs in BCS class III and BCS class II have been proposed, in particular, BCS class II weak acids. However, a discrepancy between the in vivo BE results and in vitro dissolution results for BCS class II acids was recently observed. The objectives of this study were to determine the oral absorption of BCS class II weak acids via simulation software and to determine if the in vitro dissolution test with various dissolution media could be sufficient …
Two-stage adaptive designs with correlated test statistics.
2005
When performing a trial using an adaptive sequential design, it is usually assumed that the data for each stage come from different units; for example, patients. However, sometimes it is not possible to satisfy this condition or to check whether it is satisfied. In these cases, the test statistics and p-values of each stage may be dependent. In this paper we investigate the type I error of two-stage adaptive designs when the test statistics from the stages are assumed to be bivariate normal. Analytical considerations are performed under the restriction that the conditional error function is constant in the continuation region. We show that the decisions can become conservative as well as an…
Multivariate equivalence tests for use in pharmaceutical development.
2014
Statistical equivalence analyses are well-established parts of many studies in the biomedical sciences. Also in pharmaceutical development and manufacturing equivalence testing methods are required in order to statistically establish similarities between machines, process components, or complete processes. This article presents a choice of multivariate equivalence testing procedures for normally distributed data as generalizations of existing univariate methods. In all derived methods, variability is interpreted as nuisance parameter. The use of the proposed methods in pharmaceutical development is demonstrated with a comparative analysis of dissolution profiles.
Relationships betweenin vitrodrug dissolution andin vivoresponse
2012
In recent years there has been an effort to relate manufacturing variables to the performance of the dosage form from a clinical point of view (in terms of safety and efficacy). Consequently any control strategy or the establishment of meaningful specifications should take into consideration the clinical impact on the patient. Since plasma levels are considered to be one of the most useful surrogates for clinical safety (in that bioequivalent plasma levels are considered therapeutically equivalent) and dissolution is the best surrogate for bioavailability, it is a natural consequence that dissolution be used to establish the design space in which all the formulations would have similar safe…
High-repetition-rate source delivering optical pulse trains with a controllable level of amplitude and temporal jitters
2020
International audience; We theoretically propose and numerically validate an all-optical scheme to generate optical pulse trains with varying peak-powers and durations. A shaping of the spectral phase thanks to discrete /2 phase shifts enables an efficient phase-to-intensity conversion of a temporal phase modulation based on a two-tone sinusoidal beating. Experiments carried out at telecommunication wavelengths and at a repetition rate of 10 GHz confirm the ability of our approach to efficiently generate a train made of pulses with properties that vary from pulse-to-pulse. The levels of jitters can be accurately controlled.
Concurrent molecular dynamics simulation of spinodal phase transition on transputer arrays
1990
Abstract We describe a concurrent implementation on cost-effective transputer arrays of a molecular dynamics program to efficiently simulate physical systems consisting of thousands of mobile particles with an interaction range much shorter than the system dimensions. This program, which uses a geometric decomposition strategy and includes a distributed dynamic load balancer, has been extensively tested by simulating the two-dimensional spinodal phase separation of a large Lennard-Jones system.
Maternal phenylketonuria in two Sicilian families identified by maternal blood phenylalanine level screening and identification of a new phenylalanin…
1999
not available
Photo-acoustic phase-delayed excitation of guided waves in coated bone phantoms
2013
Photo-acoustic skeletal quantitative ultrasound enables assessment of the fundamental flexural guided wave (FFGW) propagating in bone. This mode, consistent with the F(1,1) tube mode can now be measured through a coating of soft tissue. Interference due to ultrasound propagation in the soft tissue surrounding the bone is reduced by using phase-delayed ultrasound excitation. Photo-acoustic phase-delayed excitation was done on five axisymmetric bone phantoms (1-5 mm wall thickness), coated by a 5 mm thick soft-tissue mimicking layer. A fiber head comprising a linear array of four optical fibers (400 μm diameter), illuminated by pulsed laser diodes (905 nm wavelength) generated ultrasound. Thi…
Ultrasonic Guided Wave Inspection of Bonded Lap Joints: Noncontact Method and Photoelastic Visualization
2001
The main topic of this paper is the nondestructive inspection of adhesively bonded lap joints by using ultrasonic guided (plate) waves. A noncontact, couplant-free method that employs capacitive air-coupled transducers is demonstrated for the inspection of thin aluminum joints with dimensions typical of aircraft fuselage and wing panels. Two types of bond defects, disbonded regions and regions of poorly cured (low-cohesive-strength) adhesive, are successfully detected by measuring the amplitude decrease of selected plate waves leaking from one adherend to the other one through the bondline. It is shown that proper choice of the vibrating mode structure, in terms of cross-sectional displacem…
Acoustically driven photon antibunching in nanowires.
2011
The oscillating piezoelectric field of a surface acoustic wave (SAW) is employed to transport photoexcited carriers, as well as to spatially control exciton recombination in GaAs-based nanowires (NWs) on a subns time scale. The experiments are carried out in core-shell NWs transferred to a SAW delay line on a LiNbO(3) crystal. Carriers generated in the NW by a focused laser spot are acoustically transferred to a second location, leading to the remote emission of subns light pulses synchronized with the SAW phase. The dynamics of the carrier transport, investigated using spatially and time-resolved photoluminescence, is well-reproduced by computer simulations. The high-frequency contactless …