Cyclic peptide drugs have gradually become an emerging research direction due to their some favorable properties such as high-efficiency binding affinity, high selectivity, lower toxicity, and stable metabolism. In recent years, the number of cyclic peptide drugs under clinical research has continued to increase. Unlike the previous cyclic peptide drugs, which were mostly derived from natural products and their derivatives, these cyclic peptide drugs are designed by genetically encoded display technologies which are based on rational design and in vitro evolution (such as BT1718, PTG-300, POL6326, etc). Among them, phage display technology has some advantages such as mature research system, low cost, and simpler operation that make it well recognized and praised by the majority of researchers in this field. Here, we reviewed the recent progress of applying phage display technology to explore diverse cyclic peptide libraries, which, we believe, will contribute more valuable candidate cyclic peptide drugs in clinical research.

In recent years, the phenomenon of glass transition has been gradually applied to the field of pharmaceutics. And it exhibits important influences on multiple operating units of pharmaceutical preparations, and the properties and storage of pharmaceutical intermediates and products. At present, it has been widely used in the process of preparations such as drying, granulation, coating, tableting, holt-melt extrusion, cryogenic comminution, and so on. Meanwhile, it showed guiding significance for the process of preparation intermediates and their products, such as solid dispersion, microcapsule, liposome, particle, tablet, and other preparation intermediates and their products. Therefore, this article conducts a detailed analysis and systematic summary of the application guidance of the phenomenon of glass transition in the preparation process, and its influence on the preparation intermediates and products, so as to provide theoretical guidance for preparation production and product storage.

Adulterants and counterfeits were found in some of the commercial traditional Chinese medicine (TCM) decoctions in Hongjin Xiaojie Jiaonang, Hongjin Xiaojie Pian, and Chaihuang Keli during the national drug sampling inspection. However, it was difficult to determine the species of the adulterants and counterfeits by conventional testing methods. Therefore, a total of 184 samples of the TCM decoctions and raw materials belong to the prescriptions of above mentioned traditional Chinese patent medicines, including Bupleuri Radix, Bajiaolian, Heimayi, and Shufuchong, were collected and authenticated by DNA barcoding technology. 111 ITS2 sequences were obtained from 115 commercial TCM decoctions and raw materials of Bupleuri Radix, among which 71 were Bupleurum chinense, three were B. scorzonerifolium, and 31 were closely related species in the same genus. In addition, counterfeits derived from different genera, such as Ailanthus altissima (one sample), Saposhnikovia divaricate (two samples), and Solidago decurrens (three samples), were also detected. 21 ITS2 sequences were obtained from 22 commercial TCM raw materials of Bajiaolian, among which 15 were Diphylleia sinensis and six were Dysosma versipellis and other species in genus Dysosma. For 22 Heimayi samples, PCR amplification of COI sequence was failed due to genomic DNA degradation. Among 38 Shufuchong samples, 24 COI sequences were obtained and only nine of them were the genuine species (Armadillidium vulgare) recorded in the Chinese Pharmacopoeia, 11 were Porcellio laevis, two were Mongoloniscus sinensis, and two samples could not be identified due to the limitation of database. This study demonstrates that DNA barcoding technology is suitable for the species authentication of the decoctions of traditional Chinese patent medicine prescription. It is a conductive way for the establishment of traceability system for the whole TCM industrial chain.

The development of printing ink is a challenge for binder jetting 3D printed preparations, which directly determines the quality of the printed product. This study adopted a 2³ full-factor Design of Experiment (DoE) with three central points to optimize the printing ink composition of levetiracetam 3D printed dispersible tablet based on the concept of Quality by Design. Firstly, using polyvinyl pyrrolidone K30, glycerin and polysorbate 20 as independent variables based on 40% (v/v) isopropanol aqueous solution, and weight variation, hardness, friability and dispersion uniformity of the printed tablets were used as dependent variables. Then obtained the design space of the printing ink prescription by DoE model analysis, and the response optimizer was used to obtain the optimal printing ink prescription: isopropanol aqueous solution containing 0.1% (w/w) polyvinyl pyrrolidone K30 and 4.0% (w/w) glycerin. The jetting mechanism and wettability of the printing ink were analyzed, and different strengths of personalized 3D printed tablets were prepared and characterized, which verified the rationality of the printing ink formulation. This study provided a reference for the development of printing ink for binder jetting 3D printed preparations.

The aim of this study was to investigate the effects of polyethylene glycol (PEGs) with different molecular weights (MW: 400, 1 000, 4 000) on the pharmacokinetics of baicalin, and preliminarily analyze its mechanism. Rats were gavaged with baicalin (168 mg·kg^-1) + aqueous solution or baicalin + PEGs solution and plasma samples were collected from 0 to 24 h after administration. The concentration of baicalin and its main metabolite baicalein 6-O-β-D-glucuronide (B6G) were determined at different time points by UPLC-MS/MS, and the pharmacokinetic parameters were calculated with DAS 3.0 software. The results showed that PEGs with different molecular weights could effectively increase the AUC_0-t of baicalin and B6G, increase the C_max, and prolong the t_1/2, effectively increasing the concentration of baicalin and B6G in vivo. The mechanism may be by promoting the activity of uridine diphosphate glucuronosyl-transferases 1A8 (UGT1A8) and 1A9 (UGT1A9), thereby increasing the transformation rate of baicalin and B6G. The rate of metabolism of B6G was faster than that of baicalin, suggesting that PEGs had a higher affinity for UGT1A8, and PEG400 had the most significant effect. The purpose of this study was to provide a basis for the clinical safe use of baicalin and other flavonoids and the design of new dosage forms with the participation of PEGs. The animal experiment protocol in this study was approved by the Experimental Animal Ethics Committee of Guizhou Medical University.

Environmentally sensitive hydrogels are a novel formulation that has developed rapidly in recent years. It could form semi-solid with good adhesion in the topical sites based on different physiological environments. Its long local retention time is conducive for sustained drug release, and the preparation process is relatively simple and easy to realize industrialization. This review summarized the categories, commonly used polymer, and different administration routes based on the recently published literatures. According to different response factors, it can be divided into temperature, pH, ion, light, and multiple sensitive hydrogels, among which temperature-sensitive hydrogels are the most common. The most commonly used polymers include chitosan, poly N-isopropyl acrylamide, and poloxamer. There are different administration routes for environmentally sensitive hydrogels, such as transdermal, ophthalmic, nasal, oral, vaginal, rectal, injection, etc. Environmentally sensitive hydrogels have broad prospects in clinical application.

Xanthine oxidase (XOD), catalyzing purine metabolism, is the key enzyme in uric acid (UA) biosynthesis, and becomes an important target for hyperuricemia treatment. The inhibition on XOD plays an important role in the treatment of hyperuricemia-related diseases, such as gout, as well as oxidative stress-induced tissue injury. Here, studies on the natural products with XOD inhibition are reviewed.

This study aims to establish the design space of the key processes for drop-on-powder 3D printing based on design of experiment (DoE). By utilizing Minitab, an experimental scheme with three factors, two levels and three center points was designed to analyze the factors that significantly affected the tablet quality attributes. Furthermore, the factor interactions were analyzed using Minitab. subsequently, the computer aided drafting (CAD) software was used to adjust the model volume with fixed radius/height ratio (r/h=1.25) and establish a linear regression equation between model volume and dose. As a result, the drug dose could be controlled in a flexible manner. The finally determined process parameters were: ink-jet level is 12, layer thickness is 150 μm, and the X-axis printing head speed of 635 mm·s^-1. Regression equation between drug content (y) and model volume (x) was y=0.062 x-0.582 7 (R²=0.999 9) showing good linear relationship. This indicated that robust and feasible process parameters were obtained through DoE, and the preparation of personalized-dose tablets was realized with good reproducibility.

Anxiety disorders are one of the most common mental disorders in adults, the cause of which derives from a combination of genetics and environmental factors. A series of animal models have been established according to their pathogenesis to measure the level of anxiety or induce anxiety only, and these models have been widely applied in the non-clinical evaluation of anxiolytics. In this review, we present the current trends in the study of anxiety disorders and summarize typical non-clinical anxiety animal models, including models that both measure anxiety levels and induce anxiety, and models that induce anxiety only. This review summarizes the important issues in standardized non-clinical research of anxiety disorders and proposes criteria for the selection of an appropriate R & D model.

MYB transcription factors play many important regulatory roles in plant growth and development, secondary metabolism, and stress adaptation processes. In this work, an MYB gene containing a complete open reading frame (ORF) was selected from the transcriptome database of R. palmatum L. RpMYB4 ORF and cloned, encoding a polypeptide of 245 amino acids with a molecular weight of 26.99 kDa. RpMYB4 lacks a signal peptide or transmembrane domain but contains two conserved DNA binding domains (HTH-MYB) of the R2R3-MYB subfamily at the N-terminus. Multiple-sequence alignment demonstrated that RpMYB4 shared as high as 61% identity with many MYB proteins from other species. Phylogenetic analysis showed that RpMYB4 had the closest relationship with FtMYB8 and was clustered in the S4 subfamily. Subcellular localization by confocal microscopy showed that an RpMYB4-GFP-fusion protein localized to the nucleus in tobacco. Real-time fluorescence quantitative PCR analyses revealed that RpMYB4 was differentially expressed in various tissues, with the highest expression in leaves, followed by petioles, rhizome, and roots, and with the lowest level in mature seeds. After treatment of R. palmatum L. seedlings with 200 μmol·L^-1 MeJA, the expression of RpMYB4 in leaves was down-regulated within 24 h, and significantly up-regulated after 200 μmol·L^-1 SA treatment at 12 h and 24 h. However, gene expression did not change with 200 μmol·L^-1 ABA treatment. The transcripts of RpMYB4 under drought, high temperature, and mechanical injury stresses reached a peak at 24 h, 24 h, and at 3 h, respectively, while RpMYB4 expression was inhibited by low temperature stress, reaching its lowest value at 6 h. The gene showed no significant response to salt stress. Overall, RpMYB4 was cloned from R. palmatum L. for the first time, showed high expression in leaves, and was responsive to SA and various abiotic stress treatments including drought, high temperature, and mechanical injury. The results will be useful for further analysis of secondary metabolism and stress adaptations in R. palmatum L.