ABSTRACT
In the present paper the crystallographic behavior of the carbamazepine modifications I, II and III were studied under various conditions by means of X-ray powder diffraction, IR-spectroscopy and differential-scanning-calorimetry. It was found that the crystal lattice of the carbamazepine modification I is relative stable to the applied pressure forms, whereas modification II under similar conditions undergoes a polymorphic transformation into carbamazepine modification III, the extent of which depends on compression pressure and storage time of the tablets. In the compression samples of carbamazepine modification III neither IR-spectroscopically nor X-ray-diffractionally an influence of the pressure could be found on growing up of the enantiotrophic modification I.
Subject(s)
Carbamazepine/analysis , Calorimetry, Differential Scanning , Chemical Phenomena , Chemistry, Physical , Crystallization , Pressure , Spectrophotometry, Infrared , X-Ray DiffractionABSTRACT
In the present paper the interconversion behavior of the carbamazepine modifications I, II and III under various grinding conditions (variation of milling aggregates, milling times and frequencies) were studied. Mechanical treatment of different crystal forms led to a uniform grinding product, which is characterized crystallographically as modification III. The kinetic of phase transformations were determined by means of various quantitative methods such as a IR-spectral, a X-ray-powder diffractional and a thermoanalytical one. The results obtained by different analytical methods accorded quite well.
Subject(s)
Carbamazepine/analysis , Chemistry, Pharmaceutical , Drug Compounding , Spectrophotometry, Infrared , Temperature , Time Factors , X-Ray DiffractionSubject(s)
Carbamazepine/analysis , Crystallography , Drug Compounding , Pressure , X-Ray DiffractionSubject(s)
Rectum/physiology , Swine/physiology , Age Factors , Animals , Bisacodyl/pharmacology , Digitoxin/pharmacology , Electrodes/veterinary , Female , Hydrogen-Ion Concentration , Intestinal Secretions/metabolism , Male , Membrane Potentials/drug effects , Potassium/metabolism , Sodium/metabolismSubject(s)
Sulfanilamides , Chemistry, Pharmaceutical , Drug Compounding , Drug Stability , Pressure , ThermodynamicsABSTRACT
Particle track densities up to > 3 x 10(9) per square centimeter have been measured in different samples. Rocks 17, 47, 57, and 58 have VH (Z >22) galactic cosmic ray ages of 11, 14, 28, and 13 x 10(6) years, respectively. Rock 57 has a calculated erosion rate of 10(-7) centimeter per year. Near-surface track versus depth data in rock 17 can be fit with solar flare particles that have a differential energy spectrum aE(-3); lunar samples can be used to study the history of solar activity. The uranium in the crystalline rocks occurs principally in small regions <10 to approximately 100 micrometers in size. The (low) thermoluminescence of the fines increases with depth in core 10004. With one possible exception, x-ray studies have not shown pronounced radiation damage effects. The total energy release upon heating is small up to 900 degrees C and occurs in three broad regions.
