다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

비만아 부모의 돌봄 경험: q 방법론

Chitosan has been the subject of interest for its use as a polymeric drug carrier material in dosage form design due to its appealing properties such as biocompatibility, biodegradability, low toxicity and relatively low production cost from abundant natural sources. However, one drawback of using this natural polysaccharide in modified release dosage forms for oral administration is its fast dissolution rate in the stomach. Since chitosan is positively charged at low pH values (below its pK(a) value), it spontaneously associates with negatively charged polyions in solution to form polyelectrolyte complexes. These chitosan based polyelectrolyte complexes exhibit favourable physicochemical properties with preservation of chitosan's biocompatible characteristics. These complexes are therefore good candidate excipient materials for the design of different types of dosage forms. It is the aim of this review to describe complexation of chitosan with selected natural and synthetic polyanions and to indicate some of the factors that influence the formation and stability of these polyelectrolyte complexes. Furthermore, recent investigations into the use of these complexes as excipients in drug delivery systems such as nano- and microparticles, beads, fibers, sponges and matrix type tablets are briefly described.

https://www.mdpi.com/1660-3397/8/4/1305/pdf

Chitosan based polyelectrolyte complexes as potential carrier materials in drug delivery systems.

Emodin is a natural anthraquinone derivative that occurs in many widely used Chinese medicinal herbs, such as Rheum palmatum, Polygonum cuspidatum and Polygonum multiflorum Emodin has been used as a traditional Chinese medicine for over 2000 years and is still present in various herbal preparations Emerging evidence indicates that emodin possesses a wide spectrum of pharmacological properties, including anticancer, hepatoprotective, antiinflammatory, antioxidant and antimicrobial activities However, emodin could also lead to hepatotoxicity, kidney toxicity and reproductive toxicity, particularly in high doses and with long-term use Pharmacokinetic studies have demonstrated that emodin has poor oral bioavailability in rats because of its extensive glucuronidation This review aims to comprehensively summarize the pharmacology, toxicity and pharmacokinetics of emodin reported to date with an emphasis on its biological properties and mechanisms of action Copyright © 2016 John Wiley & Sons, Ltd

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ptr.5631

Aloe‐emodin: A review of its pharmacology, toxicity, and pharmacokinetics

A rapid and specific LC-MS-MS method has been developed for simultaneous analysis of quercetin and naringenin in rat plasma. The method was applied to the pharmacokinetics studies of quercetin and naringenin after oral administration of Pollen Typhae extract. The samples were prepared by the protein precipitation method. The analysis was carried out on an ACQUITY UPLC™ BEH C18 column with gradient elution using mobile phase, which included acetonitrile and water (containing 0.1% formic acid). The flow rate was 0.4 mL/min. All analytes including internal standard (IS) were monitored by selected reaction monitoring with an electrospray ionization source. Linear responses were obtained for quercetin ranging from 0.5 to 100 ng/mL and naringenin ranging from 5 to 1000 ng/mL. The intra- and interday precisions (RSD) were less than 10.78 and 11.20%. The extraction recovery of the analytes was acceptable. Stability studies showed that quercetin and naringenin were stable in the preparation and analytical process. The validated method was successfully used to determine the concentration-time profiles of quercetin and naringenin.

/pdf/simultaneous-analysis-of-quercetin-and-naringenin-in-rat-4kdh2yjjbi.pdf

Simultaneous Analysis of Quercetin and Naringenin in Rat Plasma by Liquid Chromatography–Tandem Mass Spectrometry: Application to a Pharmacokinetic Study After Oral Administration

The mechanism of immunoregulation by Lycium barbarum polysaccharides (LBPs) was assessed by studying the effect of LBP on the immunity and the gut microbiota. LBP isolated and purified in this study was composed of nine monosaccharides, with an Mw 1,207 kDa. LBP showed immunomodulatory activity in cyclophosphamide (Cy)-treated mice by restoring the damaged immune organs and adjusting the T lymphocyte subsets. We also found that LBP increased the diversity of the gut microbiota and the relative abundances of bacteria, such as Rickenellaceae, Prevotellaceae, Bifidobacteriaceae, and so on, which were positively associated with immune traits. In addition, Caco2 cells model was used to explore the intestinal absorption of LBP. Results showed that LBP was hardly absorbed in the intestine, which suggesting that most LBP may interact with gut microbiota. These findings suggest that the immune response induced by LBP is associated with the regulation of the gut microbiota.

/pdf/effects-of-lycium-barbarum-polysaccharides-on-immunity-and-3nfqlc896z.pdf

Effects of Lycium barbarum Polysaccharides on Immunity and the Gut Microbiota in Cyclophosphamide-Induced Immunosuppressed Mice.

Determination of the phytochemical composition of Jingning fang and the in vivo pharmacokinetics of its metabolites in rat plasma by UPLC-MS/MS.

Forsythiaside is very unstable and can be affected by different conditions. Studying the stability of forsythiaside in vivo would greatly aid in accurately measuring it and evaluating its pharmacokinetics. No thorough study has been performed examining its stability during bio-sample pretreatment processing. This study is the first to completely investigate forsythiaside stability in plasma sample pretreatment processing. The time and temperature were the two key factors that determined forsythiaside stability in plasma pretreatment. Spiked plasma samples stored at 25 °C for 0.5 h or at 0 °C for 4 h were stable, and plasma samples vortexed with an internal standard (IS) and ethyl acetate were stable at 25 °C for 2 h or −20 °C for 4 h. An organic phase that was evaporated at 25 °C had high stability at temperatures greater than 37 °C. The storage time of spiked plasma and the vortex-mixed samples exerted a tremendous influence on the stability of forsythiaside. The storage, centrifugation and evaporation temperatures played indispensable roles in forsythiaside stability. During sample preparation, the reconstitution and injection times satisfied the requirements necessary for measuring forsythiaside in a pharmacokinetic study. Treating the plasma samples under the conditions investigated in this study will ensure that the data and parameters will be stable and controllable for a pharmacokinetic study and will be suitable for measuring forsythiaside in rat plasma. Moreover, this study will be a reference for both stability in other bio-matrices and pharmacokinetic studies in further research.

Forsythiaside stability in pretreated rat plasma and its pharmacokinetics after i.v. administration

Purpose To prepare the levocarnitine thermosensitive in situ gel (LCTG) and evaluate its effect on dry eye disease (DED). Methods Draize eye irritation test and other examinations were used to evaluate the eye irritation after multiple administration of LCTG. The Schirmer test, fluorescein sodium staining, HE staining and TUNEL staining were used to detect the tear secretion, corneal injury, histopathological changes of the cornea and lacrimal gland, and the apoptosis rate of cornea epithelial cells after 3 days of the administration. The conjunctival goblet cell density was detected by PAS staining, and the expression levels of matrix metalloproteinase-3 (MMP-3) and matrix metalloproteinase-9 (MMP-9) of corneal epithelial cells were detected by immunofluorescence staining after 7 days of the administration. Results LCTG is non-irritating to rabbit eyes and has good biocompatibility. LCTG administration for 3 days can significantly increase the amount of tear secretion in mice with DED, promote corneal epithelial integrity and central corneal epithelium thickness recovery, and improve the pathological morphology and structure of corneal and lacrimal gland tissues, and reduce the apoptosis rate of the corneal epithelial cells. After 7 days of the administration, the preparation can promote the proliferation of conjunctival goblet cells and down-regulate the cornea expression levels of MMP-3 and MMP-9 in epithelial cells. Conclusion The LCTG has a good curative effect on mice with DED, and the overall curative effect is better than that of levocarnitine solution.

/pdf/topical-delivery-of-levocarnitine-to-the-cornea-and-anterior-4c8vhti5lq.pdf

Jian Ni

Papers

Simultaneous Analysis of Quercetin and Naringenin in Rat Plasma by Liquid Chromatography–Tandem Mass Spectrometry: Application to a Pharmacokinetic Study After Oral Administration

Effects of Lycium barbarum Polysaccharides on Immunity and the Gut Microbiota in Cyclophosphamide-Induced Immunosuppressed Mice.

Determination of the phytochemical composition of Jingning fang and the in vivo pharmacokinetics of its metabolites in rat plasma by UPLC-MS/MS.

Forsythiaside stability in pretreated rat plasma and its pharmacokinetics after i.v. administration

Topical Delivery of Levocarnitine to the Cornea and Anterior Eye by Thermosensitive in-situ Gel for Dry Eye Disease.