1.Establishment and evaluation of a dynamic in vitro intestinal absorption model of lipid formulations.
Ying LIU ; Tao YI ; Huan DI ; Lu XIAO ; Jikui HE
Acta Pharmaceutica Sinica 2011;46(8):983-9
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.
2.Optimization of novel self-microemulsifying mouth dissolving films by response surface methodology.
Lu XIAO ; Tao YI ; Ying LIU ; Di HUAN ; Jikui HE
Acta Pharmaceutica Sinica 2011;46(5):586-91
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.
3.Influence of silica on intestinal absorption of solid self-microemulsifying drug delivery systems.
Di HUAN ; Tao YI ; Ying LIU ; Lu XIAO ; Jikui HE
Acta Pharmaceutica Sinica 2011;46(4):466-71
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.
4.Use of an in vitro lipolysis model to evaluate type I lipid formulations.
Ying LIU ; Tao YI ; Di HUAN ; Lu XIAO ; Jikui HE
Acta Pharmaceutica Sinica 2010;45(10):1307-11
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.
5.Job preferences of doctors at township health center:A discrete choice experiment in three provinces of China
Di YAN ; Huan ZHANG ; Jie CHANG ; Yang ZHAO ; Xiaoyun LIU
Chinese Journal of Health Policy 2014;(4):44-48
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.
6.Development of UPLC-Q-TOF-MS/MS combined with reference herb approach to rapidly screen commercial sulfur-fumigated ginseng.
Shan-Shan ZHOU ; Jin-Di XU ; Hong SHEN ; Huan-Huan LIU ; Song-Lin LI
China Journal of Chinese Materia Medica 2014;39(15):2807-2813
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
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methods
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standards
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Drug Contamination
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Drugs, Chinese Herbal
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chemistry
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Fumigation
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Panax
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chemistry
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Quality Control
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Reference Standards
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Sulfur
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chemistry
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Sulfur Dioxide
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analysis
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Tandem Mass Spectrometry
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methods
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standards
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Time Factors
7.The current situation of nursing staff and their turnover in township health centers
Huan ZHANG ; Wen PAN ; Di YAN ; Yang ZHAO ; Minmin ZHANG ; Xiaoyun LIU
Chinese Journal of Health Policy 2015;(8):23-28
Objective:To describe the current situation in the nursing practice and their turnover intention in township health centers, and to analyze the changing potential influence in the nursing practice scope and workloads on their intention to leave those health centers. Methods:By means of a questionnaire, we conducted a survey on 167 nurses and interviewed 44 of them, all from 45 township hospitals within three provinces in China. Results:Since the healthcare system reform, the nursing workload in the township health centers significantly increased. 62% of the re-spondents considered their workload as heavy. Typically, the nursing work accounted for about 60% and the public health service work accounted for only 21% of the working hours. About 30% of the respondents were intended to leave their current job. The participating public health service was associated with intention to leave the job after con-trolling the province, workload, marital status, formal position, educational level and length of nursing service (P<0. 05). Conclusions:Since the healthcare system reform, the nursing practice scope in township health centers has been expanded and the workload increased considerably. But so far, expanding the scope of the nursing work may have potentials in reducing the intention of nurses to leave their current positions.
8.Ethical Reflection on the Technique of Mitochondria Replacement
Chinese Medical Ethics 2018;31(7):873-878
In 2016,the world's first birth by mitochondrial replacement technology was born.In 2017,UK Human Fertilisation & Embryology Authority approved the first application by Newcastle Fertility at Life for the use of mitochondrial replacement to treat patients.The technology has aroused controversy over gene modification of hu-man reproductive system,and some scholars have expressed their concerns and objections from the perspective of ethics.This paper would respond to these ethical concerns from three aspects of technical security,reproductive system gene modification and parenthood,oppose to call the technique of mitochondria replacement as the term"three parent test-tube baby technology",and clear that the application of mitochondrial replacement technology can be justified by ethics on the premise of ensuring safety and effectiveness.
9.Optimization of novel self-microemulsifying mouth dissolving films by response surface methodology.
Lu XIAO ; Tao YI ; Ying LIU ; Di HUAN ; Ji-kui HE
Acta Pharmaceutica Sinica 2011;46(5):586-591
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.
Administration, Oral
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Biological Availability
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Cellulose
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analogs & derivatives
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chemistry
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Drug Compounding
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methods
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Drug Delivery Systems
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methods
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Emulsifying Agents
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chemistry
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Emulsions
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Hypromellose Derivatives
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Indomethacin
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administration & dosage
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Methylcellulose
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analogs & derivatives
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chemistry
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Particle Size
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Solubility
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Surface Properties
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Tensile Strength
10.Influence of silica on intestinal absorption of solid self-microemulsifying drug delivery systems.
Di HUAN ; Tao YI ; Ying LIU ; Lu XIAO ; Ji-kui HE
Acta Pharmaceutica Sinica 2011;46(4):466-471
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.
Animals
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Biological Availability
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Drug Delivery Systems
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methods
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Emulsions
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Indomethacin
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administration & dosage
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pharmacokinetics
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Intestinal Absorption
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Lipolysis
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Rats
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Rats, Sprague-Dawley
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Silicon Dioxide
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administration & dosage
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chemistry
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Solubility