A thermal analysis method to predict the complete phase diagram of drug-polymer solid dispersions.
Summary of "A thermal analysis method to predict the complete phase diagram of drug-polymer solid dispersions."
The aim of this work was to develop a method which uses experimentally obtainable data to predict the complete phase diagram of drug-polymer solid dispersion systems, for the first time in literature. Felodipine-poly(acrylic acid) (PAA) solid dispersion was used as an example to illustrate the application of this method. Samples were prepared with different drug loading and analyzed using differential scanning calorimetry (DSC). Values of the drug-polymer interaction parameter χ(T(m)) were calculated from the drug crystal melting point depression data. Since χ is a function of temperature (χ∼1/T) according to the Flory-Huggins theory, the obtained χ-T relationship thus enabled calculation of the complete temperature-composition phase diagram of a drug-polymer solid dispersion system. In experiments, felodipine was shown to be immiscible with PAA in almost the whole range of drug content at room temperature. Two glass transition temperatures were observed, corresponding to almost pure felodipine and pure PAA, respectively, in consistent with the predicted phase behavior.
Department of Chemical Engineering, Tsinghua University, Beijing, China.
This article was published in the following journal.
Name: International journal of pharmaceutics
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/20727391
- DOI: http://dx.doi.org/10.1016/j.ijpharm.2010.08.013
In this study, minor-addition elements such as Si, Co, Cr, W, Mo, and Ti were added to matrix to improve the wettability between the diamonds and Cu matrix. The pressureless liquid-phase sintering tec...
For analysis of the gaseous thermal decomposition products of polymers, the common techniques are thermogravimetry, combined with Fourier transformed infrared spectroscopy (TGA-FTIR) and mass spectrom...
Modulated photothermal radiometry is a non-destructive and contactless technique for the characterization of materials. It has two major advantages: a good signal-to-noise ratio through a synchronous ...
We study the surface phase diagram of the three-dimensional kinetic Ising model below the equilibrium critical point subjected to a periodically oscillating magnetic field. Changing the surface intera...
The industrial importance of the U-Al-Si system stems from the fact that during processing the Al-based alloy (containing Si as impurity), used for the cladding of U (fuel in nuclear reactors), underg...
This study aims to improve Skin Self-Examination accuracy by a simple cost effective intervention requiring participants to complete a mole-mapping diagram.
RATIONALE: DNA analysis of tumor tissue may help doctors predict how well patients will respond to treatment. PURPOSE: This research study is studying biomarkers in tissue samples from pa...
RATIONALE: Studying samples of tissue from patients with cancer in the laboratory may help doctors learn more about changes that occur in DNA and identify biomarkers related to cancer. It ...
The goal of this clinical research study is to evaluate whether thermal imaging (recording body temperature) can be used to check the body's response to cancer therapy. Primary Objective:...
In earlier work, the Sponsor developed a computer image processing system for analysis of pain diagrams from patients with chronic pain. This system was then tested in a study in over 500 ...
Medical and Biotech [MESH] Definitions
An extraction method that separates analytes using a solid phase and a liquid phase. It is used for preparative sample cleanup before analysis by CHROMATOGRAPHY and other analytical methods.
Technique by which phase transitions of chemical reactions can be followed by observation of the heat absorbed or liberated.
Functionalization of exogenous substances to prepare them for conjugation in PHASE II DETOXIFICATION. Phase I enzymes include CYTOCHROME P450 enzymes and some OXIDOREDUCTASES. Excess induction of phase I over phase II detoxification leads to higher levels of FREE RADICALS that can induce CANCER and other cell damage. Induction or antagonism of phase I detoxication is the basis of a number of DRUG INTERACTIONS.
A method of chemical analysis based on the detection of characteristic radionuclides following a nuclear bombardment. It is also known as radioactivity analysis. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.