Objective To prepare quercetin nanocrystals,improve their dissolution rate,and investigate the effects of different stabilizer types and ratios on the stability of nanocrystals.Methods Quercetin nanocrystals were prepared by solvent ultrasonication,and three different stabilizers(polyvinylpyrrolidone-K30,poloxamer F188 and sodium dodecyl sulfate)were compared.The particle size was used as a screening index to investigate the stability of placement,the microscopic morphology of nanocrystals was characterized by scanning electron microscopy,infrared spectroscopy and X-ray diffraction,and the mechanism of action between stabilizers and nanocrystals was discussed.Results Through experimental screening,the results showed that povidone K30 had the best stable performance,the nanocrystals were also in the form of rod crystals,and the dissolution rate of nanocrystals was significantly higher than that of active pharmaceutical ingredients.Conclusion The type and amount of stabilizer will affect the stability of nanocrystals.

Objective To study the accuracy and safety of oral mucosal exfoliated cell specimens used in the bedside rapid detection of MTHFR C677T genotype by using the fluorescent probe method.Methods The outpatients and inpatients with hypertension visited and admitted in the department of cardiovascular medicine of this hospital from January 2019 to September 2020 were selected.The plasma homocysteine (Hcy) level in all patients was detected in the laboratory,a total of 482 hypertensive patients with Hcy≥10 μmol/L were se-lected,and the oral mucosal cells and whole blood sample were collected in all patients,and the genotypes of the above specimens were detected by the oral mucosal exfoliative cell fluorescent probe method and whole blood sample contrast reagents.If the two test results were inconsistent,the "gold standard" Sanger sequen-cing method was used to detect the whole blood sample for the final determination of MTHFR C677T geno-type.The coincidence rate was compared between the two detection methods,and the probability of adverse e-vents during the samples collection was observed and recorded.The accuracy and safety of fluorescence probe method for detecting MTHFR C677T genotype in the patients with oral mucosa exfoliation was evaluated.Re-sults The oral mucosal exfoliated cell samples and whole blood samples from 482 hypertensive patients were successfully collected,and no obvious adverse reactions occurred during the sampling process.The incidence rate of total mutation of MTHFR C677T gene detected by the fluorescence probe method and contrast reagent all were 73.23％ (353/482),the coincidence rate of homozygous wild type (CC type) in MTHFR C677T gene detected by the two methods was 100.00％ (95％CI:97.11-100.00),which of heterozygous mutant type (CT type) was 99.14％ (95％CI:96.91-99.76),which of homozygous mutant type (TT type) was 99.17％(95％CI:95.47-99.85),the total coincident rate of MTHFR C677T genotype was 99.38％ (95％CI:98.19-99.79)and the detection results consistency Kappa value was 0.9902.Conclusion The detection of MTHFR C677T gene mutation in oral mucosal exfoliated cells by fluorescent probe method is simple with less invasion,moreover which is rapid,safe and accurate.

Transdermal preparations can effectively avoid the first-pass effect and have good clinical medication compliance.Transfersomes(TF),as a novel deformable lipid vesicle with good skin penetration efficiency and encapsulation rate,exert their efficacy by maintaining stable plasma concentration in vivo.They are novel transdermal absorption preparations with great development prospects.This article summarized the current research on TF,including the preparation technology,evaluation indexes,and clinical application,and prospected its research prospects.

Abstract Hydrogels are widely used in biomedical fields such as drug delivery, wound dressings and tissue engineering because of their good biocompatibility and biodegradability. According to the source of material, it can be divided into synthetic material hydrogel and natural material hydrogel. Natural polysaccharide hydrogel not only can be used as material, but also has unique pharmacological activity and better mechanical properties, gradually become the preferred material. Dynamic covalent hydrogels have attracted much attention due to their structural flexibility, self healing performance and environmental responsiveness. In this paper, the dynamic bond mode natural polysaccharide hydrogel systems are classified and summarized, and the research status of the construction of this kind of hydrogel in drug delivery and tissue repair are summarized, to provide reference for the application of new polysaccharide hydrogels in clinical application.

Ananas comosus L. leaves,the leaves of pineapple,have a variety of medicinal values. Therefore,they can be used to prevent and treat many diseases. Pineapple leaves are actually safe that few studies have shown the side effects. The chemical composi-tion,medicinal value,toxicity and safety of pineapple leaves were summarized in the article, and the quality research was described simply as well.

Objective: To optimize the formula and preparation technology of cantharidin chitosan bioadhesive microspheres.Methods: The microspheres were prepared by a spray drying method.A single-factor experiment was used to study the effect of chitosan with different molecular weight on the gastric mucosa adhesion rate were also studied, and the effects of different drug loading ratio, concentration of chitosan acetic acid solution and speed of peristaltic pump on the loading rate were also studied.The cantharidin entrapment efficiency as the studying index, a response surface method was used to further optimize the formula.Results: The best formula and preparation process of cantharidin chitosan bioadhesive microspheres were as follows: the concentration ratio of antharidin to chitosan was 19.83% , the concentration of chitosan acetic acid solution was 0.77% , and the peristaltic pump flow rate was 9.225 ml·min-1.With the best formula, the entrapment efficiency of cantharidin chitosan bioadhesive microspheres was 90.14%.Conclusion: The microsphere preparation by the spray drying method is stable and repeatable.Cantharidin chitosan bioadhesive microspheres have high entrapment efficiency and promising biological adhesion.

The unique solution-gel transition property of in-situ gel makes it have advantages of good histocompatibility, long residence time, high local concentration, promising bioavailability and so on.This paper summarized the different types and the latest research progress in Chinese medicine targeting preparations of in-situ gel in order to provide reference for the application of in-situ gel in Chinese medicines.

Objective:To investigate the effect of surfactants on contact angle of pharmaceutical excipients and further study the effect of surfactants at different concentrations on the wettability of excipients and the effect of of surfactants and excipients at different proportions on the wettability of tablets. Methods:Different kinds of excipients were selected for tabletting,and surfactant solutions at different concentrations were prepared. The contact angle of the solutions on the surface of the tablets was measured by a contact angle tester. Results:The contact angle between the surfactants below the critical micelle concentrations and the tablets was the smallest and the wettability was the best. The change of the contact angle on the tablets with hydrophilic materials was less than that with hydropho-bic ones for most of the surfactants at the same concentration. Conclusion:After the addition of surfactants,the contact angle of excip-ient tablets significantly decreases, however, the contact angle will be stable after the amount of surfactants reaches a certain ratio, which shows significant reference value for tablet formula design.

Objective Enzyme triggered multi unit colon targeting mini tablet of indomethacin were prepared,in order to improve the target treatment of colon disease.Methods Different proportion of enteric layer and chitosan layer were screened to optimize the prescription.The colon targeting mini tablets were prepared by direct compression method.The drug release properties were investigated in different release medium.Rats were used to investigate the distribution of tissue in vivo.The Beagle dogs were used to study the pharmacokinetics and bioavailability.Results The optimum chitosan layer prescription:coating liquid concentration was 2％,plasticizer three citric acid ethyl ester (TEC) was 15％,an anti sticking agent amount of talc was 30％,coating weight was 5％;Enteric layer prescription:coating liquid solid content was 20％,plasticizer content of TEC was 5％,anti sticking agent talc powder dosage was 40％,coating weight was 3％.The chitosan multi unit colon targeted preparation seldom released in rat stomach and small intestine,released slowly in colon.The pharmacokinetics parameters in Beagle dogs were:Cmax =(3.25 + 0.672) mg·L-1,tmax =(2.00 + 0.014) h,AUC(0.∞) =(10.2 +0.871) mg·L-1 ·h,MRT (0-∞) =(2.82 + 0.180) h,CL =(2.46 + 0.202) L·h-1 ·kg-1.The release time of mini tablets for colon targeted was significantly prolonged and preserved stable blood concentration.Conclusion The enzyme triggered multi unit colon targeting mini tablet of indomethacin showed good target to colon and sustained release effect,providing an important reference for the development of preparation of indomethacin for the treatment of colon disease.

Bioadhesive delivery systems with sustained release characteristics can promote the absorption and increase the bio-availability of drugs by prolonging the residence time on the applied site. The evaluation of adhesion property of bioadhesive drug deliv-ery systems is important because the sustained release effect and the absorption are closely related with the adhesion. The methods for the evaluation of the adhesive properties of bioadhesive drug delivery systems in vitro were summarized in the article, including determi-ning the minimum peel force, measuring the residues on mucosa surface, determining the retention time on mucosal surface, measuring the swelling and the viscosity of fluid and so on, and the operation of some methods were described simply as well.