Authors:Agata Górniak, Alina Wojakowska, Bożena Karolewicz, and Janusz Pluta
Acetylsalicylicacid (aspirin), which is also a poorly water soluble compound, has been used as an analgesic, antipyretic, and anti-inflammatory nonsteroidal drug (agent) for more than a century. In recent years, however, since the time when it was demonstrated
Carswel, G. K., Johnson, C. M., Shillito, R. D., Harms, C. T. (1989) O-acetylsalicylicacid promotes colony formation from protoplasts of an elite maize inbrend. Plant Cell Rep. 8 , 282-284.
O-acetylsalicylicacid promotes colony
Authors:Luigi Campanella, Valentina Micieli, Mauro Tomassetti, and Stefano Vecchio
In this article, the quantitative determination of acetylsalicylic acid (ASA) contained in two of the most commercially available
pharmaceutical formulations was performed using differential scanning calorimetry (DSC) after a thermoanalytical characterization
and a preliminary test on compatibility of ASA with three of the most commonly considered excipients [cellulose (CE), starch
(ST) and sodium saccharin (SS)]. Finally, the analytical results obtained were compared with those derived by titrimetry and
two UV spectrophotometric methods: i.e. a ‘direct method’ and a method based on first-order derivative UV spectra.
Authors:Aneta Hałka, Paweł Płocharz, Andrzej Torbicz, and Tadeusz Dzido
We have investigated the use of pressurized planar electrochromatography (PPEC) and planar chromatography (TLC) for reversed-phase separation of a mixture of acetylsalicylic acid, caffeine, and acetaminophen. The mixture was separated on C18 plates; the mobile phase was prepared from acetonitrile (ACN), buffer, and bidistilled water. The effects of operating conditions such as mobile phase composition, type of the stationary phase, and mobile phase buffer pH on migration distance, separation selectivity, and separation time in TLC and PPEC were compared. The results showed that pressurized planar electrochromatography of these drugs is characterized by faster separation, better performance, and different separation selectivity. In conclusion, PPEC is a very promising mode for future application in pharmaceutical analysis.
Crystallisation is generally regarded as a nucleation — growth mechanism of a solid phase and often studied using thermo chemical
methods. The present work postulates an analogy to melting processes, looking at melting as nucleation — growth of a liquid
phase. The melting process of acetylsalicylic acid single crystals was investigated by DSC measurements under isothermal conditions.
The fraction of material molten after a certain time period, α(t), was calculated by integrating the DSC curves. The resulting kinetic curves were fitted using the Avrami-Erofeev equation:
–ln(1–α)=ktn, where parameter n was analysed. According to established methods, functions I('2')=[t('2')]/[t('2')+t('3')]100% and I('3')=[t('3')]/[t('3')+t('2')]100% were introduced, where t('2') and t('3') is the absolute time of consumption two- and three-dimension nuclei growth, respectively. Applying correlation analysis,
relationships between two- or three-dimensional growth and the independent variables describing the single crystals (for strictly
definite trajectories into the space of sizes) were found. Particular correlations were:a) Two-dimensional growth is a function
of the total surface area of the crystal, S, and of the surface area of the (ac)-face, Sac; b) Three-dimensional growth is a function of S/M (where M is the mass of the single crystal). It is also a function of Sac/M and of S. The obtained experimental data are explained by the ‘layer’ structure of crystals of acetylsalicylic acid.
Authors:J. Juárez-Calderón, A. Negrón-Mendoza, V. Gómez-Vidales, and S. Ramos-Bernal
Electron paramagnetic resonance (EPR) was used to investigate the dosimetric properties of two pharmaceutical preparations
containing acetylsalicylic acid, Aspirin® and Cafiaspirin®. The EPR spectra of the irradiated samples were found to have an
asymmetric absorption characterized by a major resonance at g = 2.0033. Dose response was investigated between dose ranges of 2 to 95 kGy for 60Co-gamma rays. Fading characteristics and dependence on temperature irradiation were also studied. We suggest that commercial
Aspirin® and Cafiaspirin® tablets can be used as dosimeters in the case of a short accident.
Authors:R. Bettini, A. Rossi, E. Lavezzini, E. Frigo, I. Pasquali, and F. Giordano
Aim of this work was to investigate the solid-state characteristics of micronized acetylsalicylic acid (ASA), produced by
rapid expansion of a supercritical carbon dioxide solution (RESS) and to assess whether a correlation could be found between
process parameters and solid-state characteristics. Drug solubility in supercritical CO2 was first assessed under various pressure and temperature conditions. DSC, FT-IR, PXRD, SEM, laser light scattering and HPLC
were used to characterise the solid phases produced by the RESS. The obtained particles were crystalline, with spectroscopical
and diffractometrical pattern overlapping those of the starting available product. However, a strong reduction of particle
size was obtained, linearly correlated to pressure imposed during the RESS process, while temperature did not seem to have
a major effect. Similar influence of pressure was observed on the final melting temperature of the micronized ASA. The application
of a mathematical model allowed to conclude that the melting temperature depression of RESS-prepared ASA powders can be attributed
to the decrease of particle dimension rather than to the formation of different solid phases or impurities.