01. October 2018
In this study, a set of 24 experiments was designed to understand the combined effect of different process parameters, i.e. material feed rate, liquid-to-solid (L/S) ratio, screw speed, and screw configuration on the residence time distribution, granule morphology, and particle size distribution in twin screw wet granulation of microcrystalline cellulose. It was shown that residence times were longer at higher L/S and lower screw speeds. However, the most dominant effect on mean residence time...
15. August 2018
Pharmaceutical tablets contain a variety of active substances and excipients which could be monitored by Raman spectroscopy/microscopy. Raman microscopic spectra are affected not only by the sample composition but also by preparation/measurement conditions. The character and variability of surface morphology (of tablet slices), the appropriate levels of focusing and other adjustable settings of the measurement instrumentation represent important parameters to be considered for obtaining...
20. May 2018
The influence of particle morphology and size of alpha-lactose monohydrate on dry granules and tablets was studied. Four different morphologies were investigated: Two grades of primary crystals, which differed in their particle size and structure (compact crystals vs. agglomerates). The materials were roll compacted at different specific compaction forces and changes in the particle size distribution and the specific surface area were measured. Afterwards two fractions of granules were pressed...
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...
09. February 2017
Abstract The effects of propellant type, cosolvent content, and air humidity on the morphology and solid phase of the particles produced from solution pressurized metered dose inhalers containing the corticosteroid beclomethasone dipropionate were investigated. The active ingredient was dissolved in the HFA propellants 134a and 227ea with varying levels of the cosolvent ethanol and filled into pressurized metered dose inhalers. Inhalers were actuated into an evaporation chamber under controlled...
25. July 2016
Abstract Edible films from the blending hydroxypropyl methylcellulose (HPMC) with hydroxypropyl starch (HPS) have been developed. This work focuses on the relationship between morphologies and mechanical properties of such systems. To aid understanding of blend morphology, a new technique used to identify the two phases through dying of the HPS by iodine has been developed, which provided a simple and convenient way to clearly distinguish between HPMC and HPS phases. It was found that the blend...
25. June 2016
Abstract In this work the nucleation of different polymorphs of isonicotinamide (INA) from different solvents has been studied. The metastable zone width of INA in cooling crystallization from five different solvents has been investigated and attempts have been made to reveal the link between the INA molecular self-association to the polymorphism of the nucleated crystals using ATR FT-IR (Attenuated Total Reflectance Fourier Transform Infrared) and Raman spectroscopy. Raman and IR spectra of...
25. April 2016
In the present study, the effect of Hydroxy Propyl Methyl Cellulose (HPMC) on the crystallization of ortho-aminobenzoic acid (OABA) was investigated by seeded and unseeded cooling crystallization experiments. The influence of HPMC on the induction time, crystal shape of Forms I and II of OABA and the polymorphic transformation time was studied. Furthermore, the capability of HPMC to inhibit growth of Form I was evaluated quantitatively and modelled using population balance equations (PBE)...