Influence of Drug Lipophilicity on Terpenes as Transdermal Penetration Enhancers

Percutaneous absorption-enhancing effects on the skin of hairless mice of 11 monoterpenes [1, (+)-limonene; 2, (?)-menthone; 3, (+)-terpinen-4-ol; 4, α-terpineol; 5, 1,8-cineole; 6, (+)-carvone; 7, (?)-verbenone; 8, (?)-fenchone; 9, p-cymene; 10, (+)-neomenthol; and 11, geraniol] were investigated using three different model drugs (caffeine, hydrocortisone, triamcinolone acetonide [TA]) with varying lipophilicities. Terpenes were applied at 0.4 M in propylene glycol (PG) to mouse skin. The model drugs were applied as suspensions in PG 1 hr following enhancer pretreatment. The combination of terpenes in PG provided significant enhancement of the permeation of caffeine through mouse skin. The most active compounds 10 and 11 increased permeation by between 13-fold and 16-fold. The terpenes also enhanced the delivery of hydrocortisone, but not to as great an extent. The most active compounds 3 and 4 increased permeation between 3.9-fold and 5-fold. The compounds examined did not significantly increase the delivery of TA. The most active compound 4 only increased delivery 2.5-fold, while the next most active compound 6 only increased delivery 1.7-fold. Overall, these results indicate that the combination of terpenes with PG can significantly increase the transdermal penetration of the hydrophilic drug caffeine and the polar steroid hydrocortisone.     

Effects of Compressive Stress on Magnetization Components of a Line Pipe Steel Cube

Abstract

Tensor hysteresis loops are measured for a pipeline steel cube while compressive stresses are applied orthogonally to the applied field direction. Total magnetization vectors are calculated with the applied magnetic field in each of the three cube directions. The magnetization components are compared and analyzed for different applied stresses.     

Statistical Optimization of a Controlled Release Formulation Obtained by a Double Compression Process: Application of an Hadamard Matrix and a Factorial Design

Abstract

A formulation containing an antiinflammatory agent (diclofenac sodium), two inert matrices (ethylcellulose and polyvinyl chloride) and two lubricants (magnesium stearate and talc) was optimized by a double compression process

In a first stage, preliminary trials were performed in order to study the effect of lubricants added before and after precompression

An Hadamard matrix H(8) was applied to estimate the main effects of four parameters: applied force at the upper punch (UPF) during precompression, particle size range after grinding, UPF during the final compression and concentration of ethylcellulose added before the final compression

Following the Hadamard matrix, a factorial design 2² was built. The complete linear models were fitted by regression for each response reflecting the compression behaviour and dissolution kinetics

In an optimal point, the validation was carried out with the area under the dissolution curve, being the major response to be optimized

The dissolution curves were well fitted by the Weibull distribution     

The significance of theoretical concepts in activity theory for applied research in aviation

This paper considers theoretical issues in Activity Theory (AT) as applied to pilot performance, with a focus on the inter-relationship of theoretical and applied research in psychology. This paper will discuss the significance of theoretical psychological research for the resolution of applied problems using the examples in aviation. Special attention will be given to the spatial orientation of the pilot during flight in non-standard and accidental conditions.     

Dynamic Remanent Vortices in Superfluid 3He-B

We investigate the decay of vortices in a rotating cylindrical sample of ³He-B, after rotation has been stopped. With decreasing temperature vortex annihilation slows down as the damping in vortex motion, the mutual friction dissipation α(T), decreases almost exponentially. Remanent vortices then survive for increasingly long periods, while they move towards annihilation in zero applied flow. After a waiting period Δt at zero flow, rotation is reapplied and the remnants evolve to rectilinear vortices. By counting these lines, we measure at temperatures above the transition to turbulence ∼0.6 T _c the number of remnants as a function of α(T) and Δt. At temperatures below the transition to turbulence T≲0.55 T _c, remnants expanding in applied flow become unstable and generate in a turbulent burst the equilibrium number of vortices. Here we measure the onset temperature T _on of turbulence as a function of Δt, applied flow velocity v=v _n−v _s, and length of sample L.     

Reinvestigation of dynamic materials model analysis of 99.94% purity aluminium

Abstract

This paper explains the drawbacks in the recent investigations carried out by Puchi et al. on the dynamic materials modelling concepts applied to analysis of hot rolling of commercial aluminium alloys.     

Comparison of two paddle wheel geometries within the filling chamber of a rotary tablet press feed frame with regard to the distribution behavior of a model powder and the influence on the resulting tablet mass

Objective: The purpose of this study was to compare the influence of two different paddle wheel geometries on the distribution behavior of a model powder within the filling chamber of the modified feed frame of a rotary tablet press. Moreover, both paddle wheels were compared regarding their influence on the resulting tablet mass during the tableting process.

Significance: Insights are provided regarding the influence of the paddle wheel geometry on the powder distribution to optimize the die filling process.

Materials and methods: Avicel PH 102 served as model powder. A laser triangulator was used to scan the powder surface level within the feed frame and, combined with the determination of the angle position of the paddle wheel, an in-house written software was used to calculate the powder surface profiles and filling levels. Two experimental setups, one based on the filling chamber filled with a defined amount of powder (offline) and one using the filling chamber during tableting (inline) were applied.

Results: Both paddle wheel geometries caused a significantly different distribution behavior of the powder within the filling chamber. The tablets obtained with the round rod filling wheel showed significantly higher tablet masses and significantly lower standard deviations. The inflow of powder into the filling chamber appeared to be improved with the round rod filling wheel.

Conclusions: Under the applied experimental conditions, the round rod filling wheel showed obvious advantages compared to that with flat rods in terms of the uniformity of tablet masses and the extent of die filling.     

Thermal Blooming of Laser Beams in the Framework of Spinor Formalism

Abstract

In this paper, we first give a survey of the spinor formalism applied to the propagation of laser beams through the atmosphere, then we discuss a numerical algorithm to solve the spinor equations. Finally, this algorithm is applied to numerical computations of thermal blooming for a Gaussian collimated beam in the steady-state regime.     

Process monitoring research with various estimator-based MEWMA control charts

Multivariate exponentially weighted moving average (MEWMA) control chart with five different estimators as population covariance matrix is rarely applied to monitor small fluctuations in the statistical process control. In this article, mathematical models of the five estimators (S₁, S₂, S₃, S₄, S₅) are established, with which the relevant MEWMA control charts are obtained, respectively. Thereafter, the process monitoring performance of the five control charts is simulated. And the simulation results show that the S₄ estimator-based MEWMA control chart is of the best performance both in step offset failure mode and ramp offset failure mode. Since the inline process monitoring of photovoltaic manufacturing is intended to be a problem of multivariate statistics process analysis, the feasibility and effectiveness of the proposed model are elaborated in the case study during the cell testing and sorting process control for the fabrication of multicrystalline silicon solar cells.     

Tablet Formulation : Genichi Taguchi's Approach

Abstract

In this paper the Taguchi Method for studying a large number of factors and interactions with only a few experiments is shortly presented and applied to the development of a tablet formulation.     

Quality quandaries: Uses of simulation

Key Point

This article provides a number of examples that show how useful simulation is in addressing many problems encountered in applied statistics.     

New Isomerization Mechanisms for Fullerenes

Abstract

There are proposed two classes of isomerization transformations for fullerene graphs: rotation and mirror reflection of the chosen part of the graph. An algorithm for generation of extended isomerization maps is developed. The algorithm is applied to C₄₀ fullerene as an example.     

MORPHIC CHARACTERISTICS OF GRAIN DUST

ABSTRACT

The theory of morphological analysis is explained. The equipment and procedures used are presented. The technique is applied to electron micrographs of cyclone tailings corn and wheat dusts. Some preliminary results are indicated.     

Thermomechanical response of 50.7 at.-%Ni-Ti alloy in the pseudoelastic regime

Abstract

The thermomechanical response of 50.7 at.-%Ni-Ti superelastic alloy has been investigated for a range of applied strains and strain rates. Parameters of interest include the critical stresses for nucleation and completion (σ _ms and σ _mf respectively) of the stress induced martensite (SIM) transformation, as well as the magnitude of the endothermal and exothermal reactions as a function of the applied strain and rate of deformation. Novel techniques including infrared thermometry and laser extensometry have been utilised, and are found to be particularly suited to experimentation with nitinol. The transformation temperatures and values of entropy and enthalpy of formation have been determined using differential scanning calorimetry.     

Piezomodulation of excitonic reflectance spectra in CuCl

We have investigated the piezoreflectance spectra of the 1s Z₃ and Z₁₂ excitons in single crystals of copper chloride CuCl at 95 K with linearly polarized light. The spectra were studied for the applied low pressure p (p lower than 1 MPa) directed along the [001], [111] and [110] axis with the wave vector k of the incident light parallel to the [110] direction. A strong piezo-optical response is observed for the Z₃ exciton to regard to the one observed for Z₁₂. From the stress-induced shifts and splitting of the excitonic levels, we have been able to deduce the shear excitonic deformation potentials: b = (–0.18 ± 0.02) eV and d = (0.30 ± 0.03) eV.     

Carbon Nanotube Alignment and Manipulation Using Electrostatic Fields

Abstract

Carbon nanotubes can be aligned and manipulated using an electrostatic dipole moment induced by an applied electrostatic field. The theory of this technique is discussed, as well as some applications.     

Acoustic wave passing through moving rigid screen

Abstract

A rigorous boundary condition for a linear acoustic wave passing through a moving rigid screen is derived from a modified theory of poroelasticity in this paper. The governing equation of the acoustic wave in the air passing through moving rigid screens. The boundary condition is found to be more general than that applied in earlier works done by the first author and his coworkers.

tion is found to be more general than that applied in earlier works done by the first author and his coworkers.     

Velocity Distribution Determination in a Laser Doppler Velocimetry Experiment by Fourier Transform of the Time-interval Probability Technique: Gaussian Distribution Case

Abstract

In this paper the Fourier transform of the time-interval probability technique is studied when applied to a laser Doppler velocity experiment where a fluid with a Gaussian velocity distribution P(v) is analysed. It is found that P(v) can be obtained very easily with a small error for very small detected signals.     

Simple Analytical Formulae for Squeezing in Unsaturated Two-photon Absorption

Abstract

By summation of the short-time expansion, a new expansion in decreasing powers of the initial photon number is obtained that gives simple analytical results. In this paper these formulae are applied to calculate the squeezing effect due to two-photon absorption and to discuss the mechanism of its generation.     

Quasi-geometrical Paraxial Approach to Fraunhofer Diffraction by Thick Planar Objects Using Phase-space Signal Representations

Abstract

Quasi-geometrical techniques for calculating the Fraunhofer diffraction produced by some thick objects are related to phase-space signal representations, such as the Wigner distribution function. In this way, the properties derived from these functions can be applied directly to obtain an adequate display of the corresponding diffraction patterns.