Polyethylene glycol (PEG) is extensively used to increasing the in vivo and in vitro stability of liposomes. However, PEGylated liposomes also produce some negative effects with further research, such as low cellular uptake, poor "endosomal escape" of pH sensitive liposome (PSL) and accelerated blood clearance (ABC) phenomenon, and this situation is referred as the "PEG dilemma". "PEG dilemma" posed severe challenges for the targeted delivery of PEGylated liposomes-loaded anticancer drugs, effective intracellular release of PEGylated PSL-encapsulated gene and protein drugs, and repeated administration of PEGylated liposomes. Therefore, it is urgent to solve the "PEG dilemma". This review focused on the definition, classification of "PEG dilemma", and discussed several possible approaches to overcome "PEG dilemma".
Antineoplastic Agents ; chemistry ; Drug Carriers ; chemistry ; Liposomes ; chemistry ; Polyethylene Glycols ; chemistry

The traditional Chinese medicine (TCM) theory of "treating heart and brain diseases with same methods (Nao Xin Tong Zhi: NXTZ)" has great significance to the treatment of cardiovascular and cerebrovascular diseases. It has been proven effective by a great deal of clinical researches. However, the underlying mechanism for this theory is still unclear. To provide insights into the potential mechanism of "NXTZ", this study attempts to deeply investigate the mechanism from two representative cardiovascular and cerebrovascular diseases, coronary heart disease (CHD) and cerebral apoplexy. First, various data resources were integrated to obtain different types of biomedical entities including drugs, targets, pathways and diseases. Then, three different approaches including text mining, biological network and enrichment analysis were utilized to recognize the potential common features between CHD and cerebral apoplexy, and the corresponding functions of drugs which could treat both diseases, thus unveiling the mechanism of NXTZ.
Brain ; drug effects ; Coronary Artery Disease ; drug therapy ; genetics ; metabolism ; Databases, Bibliographic ; Drugs, Chinese Herbal ; therapeutic use ; Heart ; drug effects ; Humans ; Stroke ; drug therapy ; genetics ; metabolism

A new dynamic in vitro intestinal absorption model for screening and evaluating lipid formulations was established by means of the characteristics of the intestinal digestion and absorption of the lipid formulations. This model was composed of two systems, including intestinal digestion and the intestinal tissue culture, which drew the evaluation method of intestinal absorption into the in vitro lipolysis model. The influence of several important model parameters such as Ca2+, D-glucose, K+ on the two systems of this model has been investigated. The results showed that increasing of Ca2+ concentration could be significantly conductive to intestinal digestion. The increasing of D-glucose concentration could stepped significantly down the decay of the intestinal activity. K+ was able to maintain intestinal activity, but the influence of different concentration levels on the decay of the intestinal activity was of no significant difference. Thus the model parameters were set up as follows: Ca2+ for 10 mmol x L(-1), D-glucose for 15 mmol x L(-1) and K+ for 5.5 mmol x L(-1). Type I lipid formulation was evaluated with this model, and there was a significant correlation between the absorption curve in vitro and absorption curve in vivo of rats (r = 0.995 6, P < 0.01). These results demonstrated that this model can be an attractive and great potential method for the screening, evaluating and predicting of the lipid formulations.

This paper report the development of a new dosage form - self-microemulsifying mouth dissolving films, which can improve the oral bioavailability of water insoluble drugs and have good compliance. A three factor, three-level Box-Behnken design was used for optimizing formulation, investigated the effect of amounts of microcrystalline cellulose, low-substituted hydroxypropyl cellulose and hypromellose on the weight, disintegration time, cumulative release of indomethacin after 2 min, microemulsified particle size and stretchability. Optimized self-microemulsifying mouth dissolving films could fast disintegrate in (17.09 +/- 0.72) s; obtain microemulsified particle size at (28.81 +/- 3.26) nm; and release in vitro at 2 min to (66.18 +/- 1.94)%. Self-microemulsifying mouth dissolving films with broad application prospects have good compliance, strong tensile and can be released rapidly in the mouth through fast self-microemulsifying.

Solid carriers had important effects on the properties of solid self-microemulsifying drug delivery systems (S-SMEDDS). In order to make the basis for further development of S-SMEDDS, the influences of silica on the absorption of S-SMEDDS were investigated. An in vitro lipolysis model was used to evaluate the influence of silica on self-microemulsifying drug delivery system digestion from intestinal tract. S-SMEDDS containing silica were prepared by extrusion/spheronization. The drug release and absorption were investigated. The results showed that lipolysis rate and drug concentration in aqueous phase after intestinal lipolysis both increased by adding silica, which was benefit to drug absorption. And silica was not benefit to absorption for slowing drug release. Consistently, there was no significant influence of silica on intestinal absorption. This study implied that the influences of silica on lipolysis rate and drug release were both amount dependent and it is suggested that silica could be used as the solid carrier but the proportion needs to be optimized.

The distribution fate and solubilization behavior of indomethacin through the intestinal tract were investigated with in vitro lipolysis model, by comparing the Capmul MCM and Labrafil M 1944 CS type I lipid formulations. The results showed that the more favorable solubilization was in the aqueous digestion phase from each lipid formulations for indomethacin. The lipolysis rate and extent were decided with chemical constitution of the lipid excipients, which meant that less indomethacin was transferred from the long chain polar oil lipid solution into the aqueous digestion phase. Increasing the concentration of indomethacin in the lipid formualitons from a solution to a suspension led to a linear increase in the concentration of indomethacin attained in the aqueous digestion phase from lipid formulations. This study also implied that adverse effects of the lipolysis rate and extent on drug absorption were could be taken into consideration when screening lipid formulations. Lipid suspensions likely had better enhancement of drug absorption. Last, this study demonstrated that a potential basis for optimizing and assessing type I lipid formulations and also researching in vivo-in vitro correlations of lipid formulations were provided by an in vitro lipolysis model.

Polyethylene glycol (PEG) is extensively used to increasing the in vivo and in vitro stability of liposomes. However, PEGylated liposomes also produce some negative effects with further research, such as low cellular uptake, poor "endosomal escape" of pH sensitive liposome (PSL) and accelerated blood clearance (ABC) phenomenon, and this situation is referred as the "PEG dilemma". "PEG dilemma" posed severe challenges for the targeted delivery of PEGylated liposomes-loaded anticancer drugs, effective intracellular release of PEGylated PSL-encapsulated gene and protein drugs, and repeated administration of PEGylated liposomes. Therefore, it is urgent to solve the "PEG dilemma". This review focused on the definition, classification of "PEG dilemma", and discussed several possible approaches to overcome "PEG dilemma".

Objective:To analyze the job preference of doctors at township health center ( THC) and provide references for formulating effective policy. Methods:238 cases of doctors were sampled from Shandong, Anhui and Shaanxi provinces. Using a discrete choice experiment, we analyzed the data with a conditional logit model. Results:The most important job attribution was salary, followed by education for children, permanent post, work location, training opportunity, and years before promotion. The OR value of the monthly income of 8 000 yuan is 7. 0 compared to 2 000 yuan. Doctors will pay 3 857 yuan and 3 294 yuan respectively for better education for children and perma-nent posts. Monthly income increasing to 8 000 yuan will reduce the quitting rate from 35% to 8%, and providing better education for children and permanent posts will reduce 5%. The permanent posts at township health center and non-permanent posts in county hospital have the same appeal to the doctor. Conclusion:When choosing a job, doc-tors at THCs valued salary the most. Improving the education level for children can be beneficial for attracting and re-taining doctors at THCs. A permanent post is more attractive to doctors than non-permanent posts at THCs.

Objective To investigate the synergistic effects of 9-cis-retinoic acid(9-cis-RA) and 8-cl-cAMP on growth inhibition and apoptosis induction in H460 and H292 cell lines of non-small-cell lung cancer(NSCLC). Methods Experimental groups included 9-cis-RA groups(1,5,10 and 20 ?mol/L),8-cl-cAMP groups(5,10,20 and 50 ?mol/L),9-cis-RA(5 and 10 ?mol/L) combined with 8-cl-cAMP(10 ?mol/L) groups and blank control group.The cell growth inhibition rates were detected by trypan blue staining,and the apoptosis of H460 and H292 cells were observed by Hoechst33258 fluorescence microscope,DNA gel electrophoresis and flow cytometer(FCM). Results 9-cis-RA inhibited the growth of H460 cells in a time-and dose-dependent manner,and induced the apoptosis of H460 cells(P

An ultra-performance liquid chromatography-quadrupole/time of flight mass spectrometry (UPLC-Q-TOF-MS/MS) combined with reference herb method was developed to rapidly screen commercial sulfur-fumigated ginseng. Sufur-fumigated ginseng reference herb was prepared using genuine ginseng by conventional procedure. Then the reference sulfur-fumigated ginseng sample was analyzed by UPLC-Q-TOF-MS/MS to identify characteristic marker components. 25-hydroxyl-Re sulfate with higher abundance was se- lected as marker compound from 8 characteristic components identified in sulfur-fumigated ginseng reference herb. The fragmentation of 25-hydroxyl-Re sulfate was extensively investigated, fragment ion m/z 879.44 with higher intensity was chosen as the characteristic ion of sulfur-fumigated ginseng. The response of ion m/z 879. 44 was improved by optimizing the MS conditions so that this ion could be used as the characteristic marker ion for screening purpose in ion extracting screening mode. The established approach was successfully applied to inspect 21 commercial ginseng samples collected from different cities in China It was found that the chemical profiles of 9 samples were similar to that of sulfur-fumigated ginseng reference herb, and the characteristic ion m/z 879. 44 of 25-hydroxyl-Re sulfate was also detected in these samples, suggesting that there were nearly 43% ginseng samples analyzed being sulfur-fumigated. This findng agreed well with the results of sulfur dioxide residues of these 21 commercial ginseng samples determined with the method documented in Chinese Pharmacopeia Compared with the method documented in Chinese Pharmacopeia, the proposed approach is more rapid and specific for screening sulfur-fumigated ginseng. SFDA of China should strengthen the enforcement to prohibit ginseng being sulfur-fumigated, so that ginseng and it preparations could be effectively and safely benefit to the health of human beings.
Chromatography, High Pressure Liquid ; methods ; standards ; Drug Contamination ; Drugs, Chinese Herbal ; chemistry ; Fumigation ; Panax ; chemistry ; Quality Control ; Reference Standards ; Sulfur ; chemistry ; Sulfur Dioxide ; analysis ; Tandem Mass Spectrometry ; methods ; standards ; Time Factors