Authors:Antonilêni Medeiros, Ana Santos, F. de Souza, I. Júnior, J. Valdilânio, J. Procópio, D. de Santana, and R. Macêdo
Compatibility studies between active drugs and excipients are substantial in the pharmaceutical technology. The objective
of the present work was to develop pre-formulated mixtures of metronidazole (MT) obtained by spray drying (SPDR) and their
thermoanalytical characterization. Dynamic and isothermal TG, conventional DSC and DSC coupled to a photovisual system were
used. DSC experiments with both techniques confirmed the homogeneity of the conventional and pre-formulated mixtures. The
TG data made possible the comparison the thermal stability of the different mixtures. Similar thermal stabilities were found
of the conventional and pre-formulated mixtures, with slower particles sizes of MT.
Authors:Antonilêni Medeiros, Ana Santos, F. de Souza, J. Procópio, Márcia Pinto, and R. Macêdo
Stability of drugs
and products has a great practical interest, which is facing to strict regulation.
Thermal studies, besides the determination of the thermal properties of the
investigated product allow the verification of possible interactions between
the drug substances and excipients. The objective of this work was to obtain
solid pre-formulates of paracetamol (PC) by spray drying (SPDR), as well as
to investigate their thermal behavior. Dynamic and isotherm TG, conventional
DSC and DSC-photovisual coupled methods were used to characterize the conventional
and pre-formulated mixtures obtained by SPDR. The results of both DSC investigations
showed slight alterations in melting temperatures, which suggests incompatibilities.
The TG decomposition data of the mixtures evidenced that the dry process via
SPDR leads to stability enhancement of the pre-formulated mixtures.
Authors:Luciana Fernandes, W. Oliveira, J. Sztatisz, I. Szilágyi, and Cs. Novák
Inclusion complexes of Lippia sidoides essential oil and β-cyclodextrin were obtained by slurry method and its solid powdered form was prepared using spray drying.
The influence of the spray drying, as well as the different essential oil:β-cyclodextrin ratio on the characteristics of the
final product was investigated. With regard to the total oil retention 1:10 mass/mass ratio as optimal was found between the
essential oil and β-cyclodextrin.
Thermoanalytical techniques (TG, EGD, TG-MS) were used to support the formation of inclusion complex and to examine their
physicochemical properties after accelerated storage conditions. It may be assumed that the thermal properties of the complexes
were influenced not only by the different essential oil/ β-cyclodextrin ratio but also by the storage conditions. In the aspect
of their thermal stabilities, complex prepared with 1:10 m/m ratio (essential oil:β-cyclodextrin) was the most stable one.
Authors:Ramona Huelsmann, Guenter J. Esper, and Reinhard Kohlus
Introduction In food industry spraydrying processes are widely used to produce dry free flowing powder starting from a liquid formulation. Since this is a one stage process with high drying capacity it has advantages compared to multi stage
Authors:P. Bowen, M. Daglish, G. Frenzer, J. -F. Ricard, and Y. Wyser
Aluminate sodalite ceramics, (Sr8Al12O24)(CrO4)2) — SACR, have been prepared from solution spray-dried precursors. The spray drying of a mixed aqueous nitrate solution gave an anhydrous powder which was thermally decomposed in air at 1350 °C to give a crystalline SACR powder with a median volume diameter of 4–6 μm. The SACR powder was dry pressed and sintered to >90% density. The yellow SACR powder showed two phase transitions between 10 and 45 °C with a 25 ° intermediate phase region indicative of a low defect concentration in the crystalline structure. A colour change observed in the sintered ceramic (changing to a mixed green/yellow) and a narrowing of the phase transition region (15–40 °C) are discussed. Dielectric measurements were consistent with the presence of two extrinsic ferroelectric transitions at 17 and 35 °C.
Authors:J. Ginés, M. Arias, C. Novák, P. Sánchez-Soto, A. Ruiz-Conde, and E. Morillo
The formation of crystalline inclusion complex of triamterene with β-cyclodextrin (β-CD) was studied, evaluating the thermal
behaviour and dispersion state of this drug in different types of binary systems. Spray-drying and co-grinding (oscillating
mill) mixtures of triameterene with β-CD were prepared in 1∶1 molar ratio. The changes of crystalline properties of original
(untreated) triamterene, β-CD, and composites obtained by co-grinding and spray-drying were investigated in comparison with
those produced in simple physical mixtures. The thermal behaviour of the different samples was investigated using DTA. X-ray
diffraction was applied as a complementary technique. The results have been explained by formation of amorphous drug particles
on spray-drying samples and co-grinding or alternatively by means of a solid dispersion formation or a combination of these
two. A contamination effect by grinding media was also observed as increasing grinding time.
The interaction among moisture content, solvent loss and glass transition temperature is relevant for processing of spray-dried
pharmaceuticals, since the glass transition temperature determines the application range of a compound. Conventional Differential
Scanning Calorimetry (DSC) does usually not allow to separate glass transitions from common kinetic effects like evaporation
or crystallization. Based on classical DSC methods, the IsoStepTM method allows the independent determination of heat capacities and kinetic effects, and thus, the separation of kinetic effects
from effects arising from heat capacity changes. This technique is used to separate glass transition and evaporation processes,
and to find the relation between moisture content and glass transition temperature for a pharmaceutical sample based on a
modified Gordon–Taylor equation.
Authors:Jutta Breitenbach, Christopher Beermann, and Günter J. Esper
Jantzen , M. ; Göpel , A. ; Beermann , C. ( 2013 ) “ Direct SprayDrying and Microencapsulation of Probiotic Lactobacillus Reuteri from Slurry Fermentation with Whey ”, in Journal of Applied Microbiology 115 ( 2013 ), pp. 1029 – 1036
Authors:Jadwiga Skubiszewska-Zięba and V. Sydorchuk
The influence of the conditions of aerosil dispersion spray drying process in the medium of overheated water steam on the
formation of microspheric granules and their porous structure was studied. Water and ammonium solutions as aerosil particles
dispersing agents and water steam and air as heat carriers were used. It was stated that the effects of spray drying depend
on the kind of dispersing medium and on the conditions of atmosphere and temperature at which drying and forming of aerosilogel
granules takes place.