04. August 2018
In this paper, we explain the crystallization process of mannitol during convective droplet drying based on the crystallization kinetics calculated from two mathematical models coupled with experimental investigations. A novel differential-reaction engineering approach was developed, correlating the mannitol crystallization behavior to the deviation of droplet drying kinetics at different drying temperatures. The model was compared with a conventional glass transition-based model and the...
02. February 2018
The purpose of the research described herein was to develop a kinetic model for quantifying the effects of conditional and compositional variations on non-covalent polymorphic and covalent chemical transformations of gabapentin.
29. June 2017
• Micronization of the pharmaceutical excipient tristearin by the PGSS process.
• Gaining of metastable α-forms of tristearin immediately after the processing.
• The lower the pre-expansion pressure the higher the degree of crystallinity.
• Stabilization of the metastable crystal form α in case of low pressure drops.
• Increase of transformation tendency of the metastable α-form by emulsifier
11. April 2017
Abstract Ribavirin (C8H12N4O5; anti-viral agent) was crystallized as two unique, phase-pure polymorphs (R-I and R-II). Calorimetrically determined isobaric heat capacities and heat of transition data were utilized to determine the solid-state transition temperature (Ttr), confirming enantiotropism, while R-I was determined to be kinetically stable at ambient temperature. Unprocessed samples of the low Tm polymorph, R-II, did not convert into R-I when held isothermally well above Ttr for 7 days....
06. April 2017
Abstract The morphology and polymorphism of mannitol particles were controlled during spray drying with the aim of improving the aerosolization properties of inhalable dry powders. The obtained microparticles were characterized using scanning electron microscopy, infrared spectroscopy, differential scanning calorimetry, powder X-ray diffraction and inhaler testing with a next generation impactor. Mannitol particles of varied α-mannitol content and surface roughness were prepared via spray...
15. December 2016
Abstract The study aims to elucidate the transformations of anhydrous olanzapine Form I (OLZ FI) into the hydrate forms, when stored at a high relative humidity or suspended in an aqueous media, in the presence of polymers. OLZ FI and physical mixtures (3:1 and 1:1, as powders or compacts) of olanzapine with polyethylene glycol (PEG-6000), polyvinylpyrrolidone (PVP K25) and hydroxypropylcellulose (HPC-LF) were stored (75%RH/25 °C, 75%RH/40 °C and 93%RH/25 °C) for 28 days. OLZ FI and the...
25. April 2016
This study consists of two experimental designs. Within the first one, suitable technique for application of model drug onto inactive pellets was evaluated and formulation and process parameters with greatest impact to process efficency and useful yield were determined. Results of experiments showed that formulation characteristics were the ones with the greatest impact on coating efficiency and that suspension layering technique was signifficantly better for drug application onto inactive...