crystal polymorphism
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Spray drying and hot-melt extrusion are among the most prevalent preparation techniques used in the pharmaceutical industry to produce amorphous solid dispersions (ASDs). This study advances previous research by integrating sample production, comprehensive analytical characterization, intrinsic dissolution rate measurements, and assessments of the behavior of ASDs under elevated temperature and humidity conditions. The study focuses on indomethacin, a widely used model for poorly soluble drugs, processed with PVP K30 or HPMC E5, both commonly used polymers. The findings demonstrate that hot-melt extruded samples exhibit superior stability against recrystallization, whereas spray dried samples achieve higher intrinsic dissolution rates. Furthermore, PVP K30 significantly outperforms HPMC E5 in the co-processing of indomethacin, enhancing both the intrinsic dissolution rate and the stability.
- MeSH
- deriváty hypromelózy chemie MeSH
- farmaceutická chemie metody MeSH
- indomethacin * chemie MeSH
- krystalizace * MeSH
- povidon chemie MeSH
- příprava léků metody MeSH
- rozpustnost * MeSH
- sprejové sušení * MeSH
- stabilita léku * MeSH
- technologie extruze tavenin * metody MeSH
- uvolňování léčiv MeSH
- vlhkost MeSH
- vysoká teplota MeSH
- vysoušení metody MeSH
- Publikační typ
- časopisecké články MeSH
The integration of 3D printing into the pharmaceutical sciences opens new possibilities for personalized medicine. Poly(lactide) (PLA), a biodegradable and biocompatible polymer, is highly suitable for biomedical applications, particularly in the context of 3D printing. However, its processability often requires the addition of plasticizers. This study investigates the use of phase diagram modeling as a tool to guide the rational selection of plasticizers and to assess their impact on the thermodynamic and kinetic stability of PLA-based amorphous solid dispersions (ASDs) containing active pharmaceutical ingredients (APIs). Thermodynamic stability against API recrystallization was predicted based on the API solubility in PLA and Plasticizer-PLA carriers using the Conductor-like Screening Model for Real Solvents (COSMO-RS), while the kinetic stability of the ASDs was evaluated by modeling the glass transition temperatures of the mixtures. Two APIs, indomethacin (IND) and naproxen (NAP), with differing glass-forming abilities (i.e., recrystallization tendencies), and three plasticizers, triacetin (TA), triethyl citrate (TEC), and poly(L-lactide-co-caprolactone) (PLCL), were selected for investigation. The physical stability of ASD formulations containing 9 wt% API and plasticizer to PLA in two ratios, 10:81 and 20:71 w/w %, was monitored over time using differential scanning calorimetry and X-ray powder diffraction and compared with phase diagram predictions. All formulations were predicted to be thermodynamically unstable; however, those containing no plasticizer or with TEC and TA at 10 wt% were predicted to exhibit some degree of kinetic stability. Long-term physical studies corroborated these predictions. The correlation between the predicted phase behavior and long-term physical stability highlights the potential of phase diagram modeling as a tool for the rational design of ASDs in pharmaceutical 3D printing.
- MeSH
- 3D tisk * MeSH
- citráty chemie MeSH
- diferenciální skenovací kalorimetrie metody MeSH
- farmaceutická chemie metody MeSH
- farmaceutická technologie metody MeSH
- indomethacin * chemie MeSH
- krystalizace MeSH
- naproxen chemie MeSH
- polyestery * chemie MeSH
- rozpouštědla chemie MeSH
- rozpustnost * MeSH
- stabilita léku MeSH
- termodynamika MeSH
- tranzitní teplota MeSH
- triacetin chemie MeSH
- změkčovadla * chemie MeSH
- Publikační typ
- časopisecké články MeSH
Nanocrystalline cerium dioxide is able to protect living cells from oxidative stress under the influence of various stress factors, in particular under the one of low temperatures. This study investigates the phase-structural transformations in aqueous solutions containing CeO2 nanoparticles (NPs) and their impact on the cryopreservation process. Differential scanning calorimetry and thermomechanical analysis were used to analyse the phase transitions in aqueous suspensions of CeO2 NPs and aqueous solutions of the cryoprotectant dimethyl sulfoxide (Me2SO) with CeO2 NPs. Various concentrations of CeO2 NPs were tested to observe their effects on the crystallization and melting behaviours. The addition of CeO2 NPs significantly altered the temperatures and enthalpies of melting and crystallization in water. Low concentrations of CeO2 NPs promoted crystallization, while higher concentrations inhibited it, reducing supercooling and recrystallization during thawing. In Me2SO solutions, CeO2 NPs raised the glass transition temperature and affected the recrystallization process, with higher concentrations leading to more pronounced vitrification and reduced recrystallization. We also investigated the regularities of the effect of CeO2 NPs on phase transitions in combined cryoprotective media with Ham's F12, fetal bovine serum and Me2SO, which can be used in future to design the cryopreservation protocols. In the complex media, CeO2 NPs decreased the metastability and altered eutectic crystallization patterns, indicating potential cryoprotective effects. In conclusion, CeO2 NPs modulate the thermophysical properties of cryoprotective solutions, enhancing vitrification and reducing recrystallization, which could improve cryopreservation efficiency. Optimizing NP concentrations is crucial for practical applications in cryopreservation.
- MeSH
- cer * chemie farmakologie MeSH
- diferenciální skenovací kalorimetrie * MeSH
- dimethylsulfoxid * chemie MeSH
- kryoprezervace * metody MeSH
- kryoprotektivní látky * chemie farmakologie MeSH
- krystalizace * MeSH
- nanočástice * chemie MeSH
- tranzitní teplota MeSH
- vitrifikace * účinky léků MeSH
- změna skupenství * MeSH
- Publikační typ
- časopisecké články MeSH
Gout is a chronic disease that is caused by an innate immune response to deposited monosodium urate crystals in the setting of hyperuricemia. Here, we provide insights into the molecular mechanism of the poorly understood inflammatory component of gout from a genome-wide association study (GWAS) of 2.6 million people, including 120,295 people with prevalent gout. We detected 377 loci and 410 genetically independent signals (149 previously unreported loci in urate and gout). An additional 65 loci with signals in urate (from a GWAS of 630,117 individuals) but not gout were identified. A prioritization scheme identified candidate genes in the inflammatory process of gout, including genes involved in epigenetic remodeling, cell osmolarity and regulation of NOD-like receptor protein 3 (NLRP3) inflammasome activity. Mendelian randomization analysis provided evidence for a causal role of clonal hematopoiesis of indeterminate potential in gout. Our study identifies candidate genes and molecular processes in the inflammatory pathogenesis of gout suitable for follow-up studies.
- MeSH
- celogenomová asociační studie * MeSH
- dna (nemoc) * genetika MeSH
- genetická predispozice k nemoci * MeSH
- hyperurikemie genetika MeSH
- jednonukleotidový polymorfismus * MeSH
- kyselina močová * MeSH
- lidé MeSH
- mendelovská randomizace MeSH
- protein NLRP3 genetika MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The insulin-linked polymorphic region is a variable number of tandem repeats region of DNA in the promoter of the insulin gene that regulates transcription of insulin. This region is known to form the alternative DNA structures, i-motifs and G-quadruplexes. Individuals have different sequence variants of tandem repeats and although previous work investigated the effects of some variants on G-quadruplex formation, there is not a clear picture of the relationship between the sequence diversity, the DNA structures formed, and the functional effects on insulin gene expression. Here we show that different sequence variants of the insulin linked polymorphic region form different DNA structures in vitro. Additionally, reporter genes in cellulo indicate that insulin expression may change depending on which DNA structures form. We report the crystal structure and dynamics of an intramolecular i-motif, which reveal sequences within the loop regions forming additional stabilising interactions that are critical to formation of stable i-motif structures. The outcomes of this work reveal the detail in formation of stable i-motif DNA structures, with potential for rational based drug design for compounds to target i-motif DNA.
- MeSH
- DNA * chemie genetika MeSH
- G-kvadruplexy * MeSH
- inzulin * chemie genetika MeSH
- konformace nukleové kyseliny MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- molekulární modely MeSH
- nukleotidové motivy MeSH
- polymorfismus genetický MeSH
- promotorové oblasti (genetika) * MeSH
- reportérové geny MeSH
- sekvence nukleotidů MeSH
- tandemové repetitivní sekvence genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The present work reviews the liquid antisolvent crystallization (LASC) to prepare the nanoparticle of pharmaceutical compounds to enhance their solubility, dissolution rate, and bioavailability. The application of ultrasound and additives is discussed to prepare the particles with narrow size distribution. The use of ionic liquid as an alternative to conventional organic solvent is presented. Herbal compounds, also known for low aqueous solubility and limited clinical application, have been crystalized by LASC and discussed here. The particle characteristics such as particle size and particle size distribution are interpreted in terms of supersaturation, nucleation, and growth phenomena. To overcome the disadvantage of batch crystallization, the scientific literature on continuous flow reactors is also reviewed. LASC in a microfluidic device is emerging as a promising technique. The different design of the microfluidic device and their application in LASC are discussed. The combination of the LASC technique with traditional techniques such as high-pressure homogenization and spray drying is presented. A comparison of product characteristics prepared by LASC and the supercritical CO2 antisolvent method is discussed to show that LASC is an attractive and inexpensive alternative for nanoparticle preparation. One of the major strengths of this paper is a discussion on less-explored applications of LASC in pharmaceutical research to attract the attention of future researchers.
The text is a contemporary continuation of an earlier publication, Kratochvíl B.: Chem. Listy 101, 3 (2007). It describes mainly the nucleation process (two-step nuclea-tion of active substances in pharmacy) and crystallization control processes (seeded crystallization and sonocrystalli-zation). The focus of the work is the description of the nucleation process monitoring by modern analytical tech-nologies, i.e., Focused Beam Reflectance Measurement (FBRM) and the BlazeMetrics system. Both methods pres-ently provide the best available information for a deeper understanding of the nucleation process mechanism in crystallizing active substances. The work is documented by high quality and original photographic attachments of the crystallizing material.Full text English translation is available in the on-line version.
- Klíčová slova
- systém Blaze, nukleace,
- MeSH
- farmaceutická technologie klasifikace metody přístrojové vybavení MeSH
- krystalizace * klasifikace metody přístrojové vybavení MeSH
- lasery MeSH
- výzkumný projekt MeSH
- Publikační typ
- přehledy MeSH
The text is a contemporary continuation of an earlier publication, Kratochvíl B.: Chem. Listy 101, 3 (2007). It describes mainly the nucleation process (two-step nuclea-tion of active substances in pharmacy) and crystallization control processes (seeded crystallization and sonocrystalli-zation). The focus of the work is the description of the nucleation process monitoring by modern analytical tech-nologies, i.e., Focused Beam Reflectance Measurement (FBRM) and the BlazeMetrics system. Both methods pres-ently provide the best available information for a deeper understanding of the nucleation process mechanism in crystallizing active substances. The work is documented by high quality and original photographic attachments of the crystallizing material.
- Klíčová slova
- systém Blaze, nukleace,
- MeSH
- farmaceutická technologie klasifikace metody přístrojové vybavení MeSH
- krystalizace * klasifikace metody přístrojové vybavení MeSH
- lasery MeSH
- výzkumný projekt MeSH
- Publikační typ
- přehledy MeSH
The aim of this study was to improve rivaroxaban water-solubility by cocrystal preparation and to understand this process. The screening with water-soluble coformers was performed via both mechanochemical and solution-mediated techniques. Two cocrystals of rivaroxaban with malonic acid and oxalic acid were prepared, and the structure of the cocrystal with oxalic acid was solved. Both cocrystals exhibit improved dissolution properties. The mechanism of the supersaturation maintenance was studied by in-situ Raman spectroscopy. The transformation into rivaroxaban dihydrate was identified as the critical step in the improved dissolution properties of both cocrystals. Moreover, the transformation kinetics and solubilization effects of the coformers were identified as responsible for the differences in the dissolution behavior of the cocrystals. In-vivo experiments proved that the use of cocrystal instead of form I of free API helped to increase the bioavailability ofrivaroxaban.
The black market for new psychoactive substances has been constantly evolving and the substances that appear on this market cause a considerable number of issues, in extreme cases leading to human deaths. While monitoring the drug black market, we detected a sample of a dissociative anesthetic methoxphenidine, the salt of which contained an unusual anion in the form of bromo- and chloro-zincate complex. Concerning the unknown and potentially hazardous properties of this sample, we performed an in vitro cytotoxicity screening in cell lines of various origins (e.g., kidney, liver, bladder) which was compared with the toxicity results of the methoxphenidine standard prepared for this purpose. The street methoxphenidine sample exhibited markedly higher toxicity than the standard, which was probably caused by the anion impurity. Since it is not usual to analyze anions in salts of novel psychoactive substances, but such samples may be commonly available at the drug black market, we have developed a method for their identification with X-ray powder diffraction (XRPD), which also enabled us to distinguish between different polymorphs/solvates of methoxphenidine that were crystallized in the laboratory. XRPD offers additional data about samples, which may not be discovered by routine techniques, and in some cases, they may help to find out essential information.
