Biomedical subjects

J Sebastian Kaerger

Publications and source records attributed to J Sebastian Kaerger.

3 recordsLinked to original sources

PubMed2004

Influence of particle size and shape on flowability and compactibility of binary mixtures of paracetamol and microcrystalline cellulose.

The influence of the size and shape of paracetamol particles on the flow and compression behavior of blends (1:1) of microcrystalline cellulose (MCC) was investigated. The effect of paracetamol particle shape was investigated by using two differently prepared samples, micronized and novel engineered Solution Atomization and Xstallization by Sonication (SAXS) particles, which exhibited similar particle size ranges (2-6 microm). The results were compared to data obtained for an untreated paracetamol sample. The blends containing SAXS particles exhibited increased bulk and tapped density and improved flow, compared to the blend containing micronized particles. This may reflect differences in shape since the SAXS particles exhibited spherical morphology. The compressibility of the blend containing untreated paracetamol was greater than blends containing the SAXS and micronized materials, which may reflect the different drug particle sizes and shapes. However, blends containing the needle-shaped particles of pure untreated sample, exhibited poor compactibility after storage at 10% RH. It was found that increasing the moisture content in the blends by storage at 44% RH resulted in an increase in the compactibility of the samples containing untreated and SAXS paracetamol with the blends containing micronized paracetamol being relatively unaffected. In general, tablets prepared from blends containing smaller particles of paracetamol exhibited significantly greater compactibility compared to tablets prepared containing the larger particle sized untreated paracetamol. The use of small, spherical drug particles may result in improvements in the bulk density, densification and compactibility of blends of paracetamol and microcrystalline cellulose.

Acetaminophen↗

PubMed2004

Processing of spherical crystalline particles via a novel solution atomization and crystallization by sonication (SAXS) technique.

PURPOSE: The objective was to develop a single-step pharmaceutical particle engineering technique able to produce particles within a well-defined particle size range while controlling macroscopic spherical morphology and mesoscopic surface topography. METHODS: Paracetamol (acetaminophen) aerosol droplets were generated by spraying a solution via either an electrohydrodynamic atomizer (EHDA) or an air pressure atomizer. The highly supersaturated droplets were collected in a suitable nonsolvent of the drug and crystallized by ultrasonication. Suspended particles were filtered, and their physicochemical properties characterized. RESULTS: The SAXS processed particles showed a relatively homogeneous particle size distribution between 1 and 5 microm. Particles were nominally crystalline in structure. The chemical structure of the active ingredient did not apparently alter during processing. Controlling the solute concentration of the air pressure atomized solution provided a means of controlling the degree of sphericity and particle-size characteristics. In comparison to micronized paracetamol particles, SAXS-produced particulates were generally more uniform in shape with increased nanometer surface roughness. CONCLUSIONS: The SAXS process provides a novel means of producing crystalline particles in a well-defined particle size range. Furthermore, the method offers a range of opportunities in controlling physical properties including surface topography and particle shape.

Acetaminophen↗

PubMed2003

The effect of mechanical processing on surface stability of pharmaceutical powders: visualization by atomic force microscopy.

Atomic force microscopy was used to investigate the influence of mechanical processing (milling) on the surface stability of salbutamol sulfate. Phase imaging, a development of tapping mode atomic force microscopy, was used to elucidate variations in the physico-mechanical properties on the surface of salbutamol sulfate crystals by measuring the phase lag of an oscillating tip in contact with the surface. Simultaneous measurements of topographical and phase images indicated an increase in disorder on the surface as milling time was increased. Specific regions on the milled samples, independent of topography, showed large variations in phase shift (> 30 degrees). These regions (not observed on the crystalline salbutamol sulfate) suggested large differences in the physical properties on the surface. It is therefore reasonable to conclude that these regions were likely attributed to mechanically induced amorphous domains.

Drug Stability↗