Latest ArticlesIn this study, 9 aztreonam prodrug compounds were designed and synthesized, and their metabolic stability in plasmas of different species (rat, mouse, dog, monkey and human) were evaluated. Species differences were observed in aztreonam carboxylates's sensitivity to the plasma esterases among different species, and the hydrolysis rates of aztreonam carboxylates in rodent plasmas were much higher than in non-rodent plasmas. Moreover, the hydrolysis rates of aztreonam carboxylates might be positively correlated with the ClogP values in human plasma. These results provide useful guidance for the further development of monocyclic β lactam prodrugs.
The study was undertaken to clarify the differences in metabolite groups between Aster yunnanensis and Pulicaria insignis to establish plant origin and identify plant resources. Non-target metabolomics of A. yunnanensis and P. insignis was undertaken with sample derivatives and gas chromatography-mass spectrometry (GC-MS). Principal component analysis (PCA), partial least-squares discriminant analysis (PLS-DA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) were used to characterize the differing metabolites of A. yunnanensis and P. insignis. Correlation analysis of these metabolites and metabolic pathway analysis allowed us to identify metabolic pathway changes between samples. Characterization of the antibacterial activity of the essential oil from A. yunnanensis and P. insignis showed that 384 metabolites were identified in the two species, including amino acids and peptides, phenylpropanoids, aromatics, glycoside, nucleotide, flavonoid, alkaloids, saccharides, vitamin, organic acid, lipids, esters, alcohol. A total of 92 differential metabolites with significant differences in content (P < 0.05, VIP > 1) were identified. In conclusion, a new method based on pre-column derivatives and GC-MS metabolomics was used to distinguish and compare A. yunnanensis and P. insignis metabolites.
Hesperidin nanosuspensions (HDN-NS) were prepared with tea saponin (TS) as stabilizer. The feasibility of TS as a natural stabilizer and the mechanism of TS stabilized nanosuspensions were investigated to provide reference for the development of green nano-preparations of hesperidin. HDN-NS was prepared by high-speed shearing combined with high-pressure homogenization. Using average particle size and polydispersity index as evaluation indexes, the effects of drug concentration, shearing speed, shearing time, homogeneous pressure and homogeneous cycles on HDN-NS were investigated by single factor experiment. The results of single factor investigation were as follows: drug concentration was 8.0 mg·mL-1, shearing speed was 16 000 r·min-1, shearing time was 2 min, the homogeneous cycles were 6 cycles at 35 MPa and 12 cycles at 100 MPa. The pH, ionic strength, zeta potential and critical micelle concentration of TS were investigated to determine the role of electrostatic repulsion in the mechanism of TS stabilized nanosuspensions. The results showed that electrostatic repulsion is involved in the mechanism of TS stabilized HDN-NS. In conclusion, at low concentration, TS can significantly reduce the particle size of HDN-NS, which indicates that TS has the potential to stabilize nanosuspension. Electrostatic repulsion is one of the mechanisms of TS stabilizing nanosuspension.
This article intended to build a component-target network to screen the effective components of Compound Suanzaoren Decoction, and to establish an efficient and rapid method for the determination of effective components. 103 compounds in the Compound Suanzaoren Decoction were identified by HPLC-Q-TOF MS/MS. 27 potential effective substances were analyzed by network pharmacology. The first six components with the largest degree were selected as effective components, including neomangiferin, mangiferin, ferulic acid, senkyunolide Ⅰ, spinosin, and 6'''-feruloylspinosin. A UHPLC method was established for determination. The chromatographic separation was performed on a Waters CORTECS T3 column (2.1 mm×150 mm, 1.6 μm) with the mobile phase of 0.1% phosphoric acid solution and acetonitrile. The results showed that the specificity was good with no interference for the chromatographic peaks. The linear was excellent within the scope of investigation, with the values of r higher than 0.999 0 for all analytes. The method had been verified to have good sensitivity, precision, accuracy, durability and stability. Therefore, the results showed that the method established was suitable for the screening and determination of effective components in Compound Suanzaoren Decoction, which provided a basis for the quality evaluation of traditional Chinese medicine.
Clarithromycin (CLA) belongs to the second generation macrolide antibiotic. The commercial crystal form of CLA is form Ⅱ, and it exhibits the poor compressibility during the tablet pressing process. Since the crystal form of drugs has a significant effect on their mechanical properties, from the perspective of crystallography, this study investigated the difference of the compressibility between CLA form Ⅰ and form Ⅱ, and analyzed the mechanism that led to such difference. On the other hand, from the perspective of pharmaceutics, we also studied the effect of filler on the compressibility of form Ⅱ. It was found that CLA form Ⅰ had improved plastic deformation than form Ⅱ because of the slip planes in its crystal structure leading to the better compressibility. Moreover, microcrystalline cellulose, pre-gelatinized starch and lactose monohydrate could improve the compressibility of form Ⅱ, and microcrystalline cellulose showed the best effect. We improve the compressibility of CLA from crystal form and filler, and also lay a foundation for the development of CLA solid preparations.
The MIKC-type MADS-box gene family plays an important role in flower development in plants. This study identifies members of the MIKC-type gene family in Cannabis sativa L. at the genome level, with the chromosomal location and linkage, evolutionary relationships, and identification of conserved motifs determined using bioinformatics tools. The results show that C. sativa contains 39 members of the MIKC-type MADS-box gene family (named CsMADS1-CsMADS39) unevenly distributed on nine chromosomes. The encoded proteins range in length from 146 to 503 amino acids, and the theoretical isoelectric points range from 5.19 to 10.12. Molecular weights range from 16 739.35 to 57 070.56 Da. The subcellular location of CsMADS genes is mainly in the nucleus. The result of conserved domain analysis showed that all genes contain the MADS conserved domain. The analysis of GO showed that all genes were annotated to 331 GO terms, which were clustered by molecular function. A phylogenetic tree showed that CsMADS genes could be divided into 14 subclasses, according to ABCDE homologous gene model; CsMADS genes are clustered with SQUA/AP1, AP3, PI, GGM13, AG, SEP/AGL2 subfamilies in Arabidopsis. There are abundant cis-acting elements in the upstream promoter region of CsMADS genes, mainly light regulatory elements. The results of real-time fluorescent quantitative PCR showed that some CsMADS genes are highly expressed in flowers and bracts, with tissue-specific expression. This study identified and analyzed the MIKC-type MADS-box gene family in C. sativa at the genome level, and provides a theoretical basis for further exploration of the function of MIKC-type genes and their role in regulating the growth and development of medicinally important hemp.
The three polymorphs (Ⅰ, Ⅱ, Ⅲ) and one amorphous (Ⅳ) form of imatinib-oxalate new salt were prepared and characterized by powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis and infrared spectroscopy, and transformation rules among the four salts were analyzed. The solubility of polymorph Ⅱ was investigated by high performance liquid chromatography. The results show that polymorph Ⅱ was stable but polymorph Ⅰ, Ⅲ and amorphous Ⅳ were unstable at room temperature. Polymorph I transformed into polymorph Ⅱ at room temperature. At relative humidity 90%, polymorph Ⅰ, Ⅱ and amorphous Ⅳ transformed into polymorph Ⅲ, but polymorph Ⅲ transformed into amorphous Ⅳ at 70 ℃. The solubility of imatinib was significantly improved after being salted with oxalic acid, and the equilibrium solubility of polymorph Ⅱ in pH 6.8 buffer solution and pure water was increased by 4.1 and 21.2 fold, respectively, as compared to bulk drug. This research provides guidance for the development and quality control of a new salt form of imatinib.
The movement and deposition of inhaled particles in the lung tissue have an important influence on the respiratory physiology of human body. The corresponding particle dynamics model plays a vital role in exploring the pathogenic factors and treatment methods of lung diseases. Such as evaluating the optimal design of pulmonary atomization drug delivery and the impact of particulate air pollutants on the lung. According to the different knowledge and modeling methods, this paper classifies, combs and analyzes several representative particle dynamics models in lung airways in recent years. We divided the mechanism models into the biological model, physical model and numerical simulation model. The biological models include in vivo imaging and pharmacokinetic methods; physical models include bionic and microfluidic chip models; the numerical models include respiratory tract model, airflow model and particle model. Moreover, the numerical solution and fluid-structure-interaction models were also reviewed, especially the application prospect of the lattice Boltzmann method.
Pulmonary drug delivery agents deliver drugs directly to the lung tissue to obtain higher local concentration, which is beneficial to the treatment of lung diseases, and may reduce the systemic side effects. Therefore, it has become the preferred drug for the treatment of many lung diseases. However, the drugs entering the lungs are easily cleared by the lung tissues, which reduce the retention time of the drugs in the lungs and affects the efficacy. Although particles with a smaller particle size (1-5 µm) are easily inhaled into the lungs, they are also easily swallowed and cleared by lung macrophages. While the porous polymer microspheres (PPMS) with larger geometric diameter (Dg > 5 µm) and low density (ρ < 0.4 g·cm-3) can not only effectively avoid the phagocytosis of alveolar macrophages, but also have a high effective deposition rate in the lungs due to the appropriate aerodynamic diameter, moreover, the polymer is biodegradable and non-toxic, so it has become a research hotspot for pulmonary drug delivery carriers. This article combined with the lung clearance mechanism of granules, summarized the preparation materials and methods of PPMS, as well as its quality control, etc. Furthermore, opinions are also put forward for the development of PPMS, to provide a reference for the in-depth study of PPMS.
This article systematically reviews the background and regulatory requirements of bioequivalence of orally inhaled and nasal drug products (OINDPs), as well as the basic regulatory requirements for the assessment by the guidelines and guidance issued in China, the United States, and the European Union. Detailed statistical evaluation method considerations and calculations of the US FDA population bioequivalence (PBE) method were presented for the evaluation of in vitro bioequivalence (IVBE) for OINDPs. Using the example described in the FDA Draft Guidance for budesonide inhalation suspension, the PBE analysis statistical parameters were calculated via the R programming, and the results were compared with that in the guidelines. Moreover, pseudo-code for the PBE calculation program was provided. This paper aims to provide guidance and references for the research and development of new drug, as well as pharmaceutical quality control, and development of generic medicinal products for OINDPs.