摘要:
A method for crystallization of a weakly acidic and/or weakly basic compound having an uncharged form and at least one charged form comprises the steps of: a) providing a solution of said compound in a solvent having an initial pH-value and an initial total concentration of said compound, said initial pH-value being chosen such that the compound is present in said solution predominantly in said charged form, said initial total concentration being chosen larger than the intrinsic solubility of said uncharged form; b) gradually changing the pH-value of said solution in a direction that leads to a decrease of said compound's solubility until reaching a predetermined target pH-value at which said solution is in a substantially saturated state and the concentration of said uncharged form is substantially equal to said intrinsic solubility thereof; and c) maintaining said solution in a substantially saturated state while allowing formation of crystals of said compound.
摘要:
A method for crystallization of a weakly acidic and/or weakly basic compound having an uncharged form and at least one charged form comprises the steps of: a) providing a solution of said compound in a solvent having an initial pH-value and an initial total concentration of said compound, said initial pH-value being chosen such that the compound is present in said solution predominantly in said charged form, said initial total concentration being chosen larger than the intrinsic solubility of said uncharged form; b) gradually changing the pH-value of said solution in a direction that leads to a decrease of said compound's solubility until reaching a predetermined target pH-value at which said solution is in a substantially saturated state and the concentration of said uncharged form is substantially equal to said intrinsic solubility thereof; and c) maintaining said solution in a substantially saturated state while allowing formation of crystals of said compound.
摘要:
Novel substituted 2,4-diamino-5-benzyl pyrimidines are described. The novel substances have antimicrobial activity and are particularly suitable for inhibiting the growth of mycobacteria. Combined with inhibitors such as diaminodiphenylsulphones, ring-substituted 4-aminodiphenylsulphones or ring and/or nitrogen-substituted diaminodiphenylsulphones, they have a marked synergistic activity.
摘要:
The present invention relates to a novel method for determining the lipophilicity of a compound of interest comprising a) providing a layer, b) impregnating said layer with a solvent A, c) applying a dissolved compound of interest on the impregnated layer, d) adding a solvent B, e) removing the solvent B after the distribution equilibrium has been reached, and f) determining the quantity of the compound of interest in at least one of the solvent phases.
摘要:
The invention deals with a method for the assessment of the effect of excipients, pH and combinations thereof on the predicted absorption properties of low solubility compounds, comprising the step of assessing a change in a flux function for a combination of a low solubility compound and an excipient at at least one predefined pH value. The method allows a fast, accurate, and economic evaluation of an excipient being capable of optimizing the absorption of drug molecules, i.e. low solubility compounds. Furthermore, animal experiments can be excluded and use of compounds can be reduced in such evaluation. Thus, screening for future formulation efficacy (pH and excipient effects on solubility and permeability) of drug candidates can be justified, since the method is fast, compound-sparing, cost-effective, and reasonably accurate.
摘要:
An integrally built, linear array of cuvettes is made of a plastic material. This array comprises a plurality of cuvettes arranged along a straight line in an array, each cuvette in the array having the same shape and dimensions, and neighboring cuvettes being connected to each other by a single web. Each of the single webs has a curved shape. The symmetry axis (Y-Y) of every cuvette forming part of said array of cuvettes lies substantially in one and the same plane (A-A) which is a symmetry plane of said cuvette array. The upper part of at least one intermediate cuvette which is located between a first cuvette located at one end of the cuvette array and a second cuvette located at the opposite end of the cuvette array is connected by a first single web to the upper part of a neighboring cuvette lying on one side of said intermediate cuvette and is connected by a second single web to the upper part of a neighboring cuvette lying on the opposite side of said intermediate cuvette.
摘要:
The invention deals with a method for the assessment of the effect of excipients, pH and combinations thereof on the predicted absorption properties of low solubility compounds, comprising the step of assessing a change in a flux function for a combination of a low solubility compound and an excipient at at least one predefined pH value. The method allows a fast, accurate, and economic evaluation of an excipient being capable of optimizing the absorption of drug molecules, i.e. low solubility compounds. Furthermore, animal experiments can be excluded and use of compounds can be reduced in such evaluation. Thus, screening for future formulation efficacy (pH and excipient effects on solubility and permeability) of drug candidates can be justified, since the method is fast, compound-sparing, cost-effective, and reasonably accurate.
摘要:
The present invention relates to a novel method for determining the lipophilicity of a compound of interest comprising a) providing a layer, b) impregnating said layer with a solvent A, c) applying a dissolved compound of interest on the impregnated layer, d) adding a solvent B, e) removing the solvent B after the distribution equilibrium has been reached, and f) determining the quantity of the compound of interest in at least one of the solvent phases.