Methods, systems, devices, and products for evaluating a fluid. Methods include introducing a sample comprising the fluid to a solvating fluid at a point in a chamber associated with the instrument at a first time to create a heterogeneous admixture; measuring concentrations of each of a plurality of components in the admixture at a plurality of distances from the point in the chamber at, at least one additional time later than the first time, each of the plurality of distances being non-zero; and estimating a relative concentration for each of the plurality of components in the fluid by extrapolating the relative concentration of each of the plurality of components in the sample at the point at the first time using the measured concentrations in the admixture at the plurality of distances.

The present invention relates to a method for determining the lipophilicity of a test compound comprising the steps of: a) providing a multiwell plate, wherein the wells comprise at the bottom a lipophilic membrane and the bottom of the multiwell plate comprises a liquid tight barrier to produce a liquid tight bottom of the multiwell plate, b) adding a non-polar solvent to the lipophilic membranes in the wells of step a), c) adding an aqueous solution comprising the test compound to the wells of step b, and d) determining the quantity of the test compound in the aqueous solution after a distribution equilibrium has been reached.

Methods for determining the lateral diffusion of one or more components are provided.

A method of measuring a hydrogen diffusivity of a metal structure is provided. The method includes providing a hydrogen charging surface at a first location on an external surface of the structure, and a hydrogen oxidation surface at a second location adjacent to the first location on the external surface of the structure. A hydrogen flux is generated and directed into the metal surface at the charging surface. At least a portion of the hydrogen flux generated by the charging surface and diverted back toward the surface is detected, and a transient of the diverted hydrogen flux is measured. The hydrogen diffusivity of the metal structure is then determined based on the measured transient.

Apparatuses and methods of measuring a hydrogen diffusivity of a metal structure including during operation of the metal structure, are provided. A hydrogen charging surface is provided at a first location on an external surface of the structure. In addition, a hydrogen oxidation surface is provided at a second location adjacent to the first location on the external surface of the structure. Hydrogen flux is generated and directed into the metal surface at the charging surface. At least a portion of the hydrogen flux generated by the charging surface is diverted back toward the surface. A transient of the diverted hydrogen fluxes measured, and this measurement is used to determine the hydrogen diffusivity of the metal structure in service.

An in vitro release testing method and system for testing the ability of formulations to deliver agents across a barrier membrane is disclosed. The method may comprise steps of providing a dosage of a semi-solid formulation containing the bioactive agent, a receptor solution, and a barrier membrane to separate the semi-solid formulation and the receptor solution. The receptor solution may be a biphasic solution or an immiscible solution. The semi-solid formulation may be contacted with one side of the barrier membrane and the receptor solution with the other side of the barrier membrane for a time sufficient to produce penetration of the barrier membrane by the semi-solid formulation. The receptor solution may be sampled and assayed to determine the concentration of the bioactive agent in the receptor solution.

The invention relates to a method for determining in vitro release rate of at least one active principle ingredient from at least one semisolid form.

A diffusion cell is described that includes a receiver compartment and a tightening ring intended to be positioned above the receiver compartment in such a way that a membrane sample can be arranged between the receiver compartment and the tightening ring. The cell further includes means for tightening by rotation of the tightening ring on the receiver compartment. Uses of such a diffusion cell, in particular for evaluating the penetration capacity of a compound of interest contained in an aerosol formulation, are also described. These uses can be applicable in an occlusive patch or semi-occlusive patch or in a formulation under occlusive or semi-occlusive conditions in the skin. The uses can also be implemented to evaluate the capacity of an aerosol formulation, an occlusive or semi-occlusive patch or a formulation under occlusive or semi-occlusive conditions to deliver a compound of interest through the skin.

A method of determining diffusion coefficient of one or more components in a polydisperse sample is provided. The method comprising the steps of: introducing an auxiliary fluid flow into a fractionation channel; introducing the polydisperse sample comprising one or more components into the fractionation channel; allowing the sample and the auxiliary fluid to create a combined flow; fractionating the combined flow into two or more fractions by diffusive sizing; subsequently separating two or more components from each fraction by creating a distribution of the components within a separation channel; detecting a characteristic of each the two or more components in each fraction; and comparing the characteristic of each component in each fraction in order to determine the diffusion coefficient of each of the one or more components in the polydisperse sample.

The present disclosure relates to a forced oxidation test system, including: forced oxidation subsystems, a first cabinet, a second cabinet, and connecting devices. Inner cavities of adjacent forced oxidation subsystems are arranged in parallel. The forced oxidation subsystems include: forced oxidation portions, inner cavities of adjacent forced oxidation portions being arranged in series. To-be-tested packages are placed on the first cabinet. The second cabinet is connected to the first cabinet through the connecting devices. The forced oxidation subsystems are arranged opposite to the to-be-tested packages. The second cabinet is configured to move along an axis of the connecting devices towards a direction adjacent to the to-be-tested packages until the inner cavities of the forced oxidation portions are sealed and mounted on the to-be-tested packages, such that a replacement gas in the inner cavities of the forced oxidation portions is permeated into the to-be-tested packages.