34 research outputs found
Nanokapsuły typu rdzeń-otoczka na bazie chitozanu
N-dodecyl derivative of cationically modified chitosan was used to prepare core-shell nanocapsules templated on liquid cores. Surfactant-free method based on ultrasound-assisted direct emulsification of aqueous solution of polysaccharide with oleic acid was applied. Formation of spherical capsules was confirmed by scanning and transmission electron microscopies. Dynamic light scattering measurements were used to determine physicochemical parameters of the obtained particles as well as to follow the process of multilayer shell formation. Confocal microscopy was applied to examine the ability of encapsulation of hydrophobic compounds inside the cores of the nanocapsules. Performed studies confirmed that hydrophobically modified cationic chitosan provides long-term stabilization of oil-in-water emulsion for biomedical applications as no toxic effect was observed in acute oral toxicity studies.Do przygotowania nanokapsuł na ciekłych rdzeniach stabilizowanych bez użycia małocząsteczkowych surfaktantów użyto N-dodecylowej pochodnej zmodyfikowanego kationowo chitozanu. Kapsuły otrzymano w procesie wspomaganej ultradźwiękami bezpośredniej emulsyfikacji fazy wodnej zawierającej modyfikowany polisacharyd oraz kwas oleinowy. Powstawanie sferycznych kapsuł potwierdzono za pomocą skaningowej oraz transmisyjnej mikroskopii elektronowej. Obrazowanie z użyciem mikroskopii konfokalnej posłużyło natomiast do zbadania zdolności do enkapsulacji hydrofobowych barwników w rdzeniach chitozanowych nanokapsuł. Stosując technikę dynamicznego rozpraszania światła wyznaczono fizykochemiczne parametry nanoemulsji oraz stwierdzono powstawanie wielowarstwowych otoczek. Przeprowadzone badania dowiodły, że zastosowanie hydrofobowo zmodyfikowanej kationowej pochodnej chitozanu pozwala na uzyskanie stabilnych w czasie emulsji typu olej w wodzie. Wykazany brak toksyczności układów w warunkach in vivo pozwala na ich zastosowanie do celów biomedycznych
Data-driven modeling of the bicalutamide dissolution from powder systems
Low solubility of active pharmaceutical compounds (APIs) remains an
important challenge in dosage form development process. In the manuscript, empirical
models were developed and analyzed in order to predict dissolution of bicalutamide (BCL)
from solid dispersion with various carriers. BCL was chosen as an example of a poor watersoluble
API. Two separate datasets were created: one from literature data and another based
on in-house experimental data. Computational experiments were conducted using artificial
intelligence tools based on machine learning (AI/ML) with a plethora of techniques including
artificial neural networks, decision trees, rule-based systems, and evolutionary computations.
The latter resulting in classical mathematical equations provided models characterized by the
lowest prediction error. In-house data turned out to be more homogeneous, as well as
formulations were more extensively characterized than literature-based data. Thus, in-house
data resulted in better models than literature-based data set. Among the other covariates, the
best model uses for prediction of BCL dissolution profile the transmittance from IR spectrum
at 1260 cm−1 wavenumber. Ab initio modeling–based in silico simulations were conducted to
reveal potential BCL–excipients interaction. All crucial variables were selected automatically
by AI/ML tools and resulted in reasonably simple and yet predictive models suitable for
application in Quality by Design (QbD) approaches. Presented data-driven model
development using AI/ML could be useful in various problems in the field of pharmaceutical
technology, resulting in both predictive and investigational tools revealing new knowledge
Molecular disorder of bicalutamide : amorphous solid dispersions obtained by solvent methods
The effect of solvent removal techniques on phase transition, physical stability and dissolution of bicalutamide from solid dispersions containing polyvinylpyrrolidone (PVP) as a carrier was investigated. A spray dryer and a rotavapor were applied to obtain binary systems containing either 50% or 66% of the drug. Applied techniques led to the formation of amorphous solid dispersions as confirmed by X-ray powder diffractometry and differential scanning calorimetry. Moreover, solid–solid transition from polymorphic form I to form II was observed for bicalutamide spray dried without a carrier. The presence of intermolecular interactions between the drug and polymer molecules, which provides the stabilization of molecularly disordered bicalutamide, was analyzed using infrared spectroscopy. Spectral changes within the region characteristic for amide vibrations suggested that the amide form of crystalline bicalutamide was replaced by a less stable imidic one, characteristic of an amorphous drug. Applied processes also resulted in changes of particle geometry and size as confirmed by scanning electron microscopy and laser diffraction measurements, however they did not affect the dissolution significantly as confirmed by intrinsic dissolution study. The enhancement of apparent solubility and dissolution were assigned mostly to the loss of molecular arrangement by drug molecules. Performed statistical analysis indicated that the presence of PVP reduces the mean dissolution time and improve the dissolution efficiency. Although the dissolution was equally affected by both applied methods of solid dispersion manufacturing, spray drying provides better control of particle size and morphology as well as a lower tendency for recrystallization of amorphous solid dispersions
How does the CO2 in supercritical state affect the properties of drug-polymer systems, dissolution performance and characteristics of tablets containing bicalutamide?
The increasing demand for novel drug formulations has caused the introduction of
the supercritical fluid technology, CO2 in particular, into pharmaceutical technology as a method
enabling the reduction of particle size and the formation of inclusion complexes and solid dispersions.
In this paper, we describe the application of scCO2 in the preparation of binary systems containing
poorly soluble antiandrogenic drug bicalutamide and polymeric excipients, either Macrogol 6000 or
Poloxamer®407. The changes in the particle size and morphology were followed using scanning
electron microscopy and laser di raction measurements. Di erential scanning calorimetry was
applied to assess thermal properties, while X-ray powder di ractometry was used to determine the
changes in the crystal structure of the systems. The dissolution of bicalutamide was also considered.
Binary solid dispersions were further compressed, and the attributes of tablets were assessed.
Tablets were analyzed directly after manufacturing and storage in climate chambers. The obtained
results indicate that the use of supercritical CO2 led to the morphological changes of particles and the
improvement of drug dissolution. The flowability of blends containing processed binary systems
was poor; however, they were successfully compressed into tablets exhibiting enhanced drug release
Compression-Induced Phase Transitions of Bicalutamide
The formation of solid dispersions with the amorphous drug dispersed in the polymeric
matrix improves the dissolution characteristics of poorly soluble drugs. Although they provide an
improved absorption after oral administration, the recrystallization, which can occur upon absorption
of moisture or during solidification and other formulation stages, serves as a major challenge.
This work aims at understanding the amorphization-recrystallization changes of bicalutamide.
Amorphous solid dispersions with poly(vinylpyrrolidone-co-vinyl acetate) (PVP/VA) were obtained
by either ball milling or spray drying. The applied processes led to drug amorphization as confirmed
using X-ray diffraction and differential scanning calorimetry. Due to a high propensity towards
mechanical activation, the changes of the crystal structure of physical blends of active pharmaceutical
ingredient (API) and polymer upon pressure were also examined. The compression led to drug
amorphization or transition from form I to form II polymorph, depending on the composition
and applied force. The formation of hydrogen bonds confirmed using infrared spectroscopy and
high miscibility of drug and polymer determined using non-isothermal dielectric measurements
contributed to the high stability of amorphous solid dispersions. They exhibited improved wettability
and dissolution enhanced by 2.5- to 11-fold in comparison with the crystalline drug. The drug
remained amorphous upon compression when the content of PVP/VA in solid dispersions exceeded
20% or 33%, in the case of spray-dried and milled systems, respectively.Polish National Science Centre
2015/16/W/NZ7/0040
Multivariate design of 3D printed immediate-release tablets with liquid crystal-forming drug - itraconazole
The simplicity of object shape and composition modification make additive manufacturing
a great option for customized dosage form production. To achieve this goal, the correlation between
structural and functional attributes of the printed objects needs to be analyzed. So far, it has not
been deeply investigated in 3D printing-related papers. The aim of our study was to modify the
functionalities of printed tablets containing liquid crystal-forming drug itraconazole by introducing
polyvinylpyrrolidone-based polymers into the filament-forming matrices composed predominantly
of poly(vinyl alcohol). The e ect of the molecular reorganization of the drug and improved tablets’
disintegration was analyzed in terms of itraconazole dissolution. Micro-computed tomography was
applied to analyze how the design of a printed object (in this case, a degree of an infill) a ects its
reproducibility during printing. It was also used to analyze the structure of the printed dosage forms.
The results indicated that the improved disintegration obtained due to the use of Kollidon®CL-M
was more beneficial for the dissolution of itraconazole than the molecular rearrangement and liquid
crystal phase transitions. The lower infill density favored faster dissolution of the drug from printed
tablets. However, it negatively a ected the reproducibility of the 3D printed object
How to obtain the maximum properties flexibility of 3d printed ketoprofen tablets using only one drug-loaded filament?
The flexibility of dose and dosage forms makes 3D printing a very interesting tool for personalized medicine, with fused deposition modeling being the most promising and intensively developed method. In our research, we analyzed how various types of disintegrants and drug loading in poly(vinyl alcohol)-based filaments affect their mechanical properties and printability. We also assessed the effect of drug dosage and tablet spatial structure on the dissolution profiles. Given that the development of a method that allows the production of dosage forms with different properties from a single drug-loaded filament is desirable, we developed a method of printing ketoprofen tablets with different dose and dissolution profiles from a single feedstock filament. We
optimized the filament preparation by hot-melt extrusion and characterized them. Then, we printed single, bi-, and tri-layer tablets varying with dose, infill density, internal structure, and composition. We analyzed the reproducibility of a spatial structure, phase, and degree of molecular order of ketoprofen in the tablets, and the dissolution profiles. We have printed tablets with immediateand sustained-release characteristics using one drug-loaded filament, which demonstrates that a single filament can serve as a versatile source for the manufacturing of tablets exhibiting various release characteristics