Preparation, Characterization and in Vitro Release of Ciprofloxacin Polylactic Acid Microspheres

Aim Ciprofloxacin polylactic acid microspheres (CFX-PLA-MS) were preparedusing solvent evaporation method from a solid-in-oil-in-water emulsion system. Methods Orthogonalexperiment was used to optimize the method of CFX-PLA-MS preparation. Microspheres werecharacterized in terms of morphology, size, encapsulation efficiency, drug loading and in vitro drugrelease. Results The physical state of CFX-PLA-MS was determined by scanning electron microscopy(SEM) and differential scanning calorimetry (DSC) . Microspheres formed were spherical with smoothsurfaces. Drug was enveloped in microspheres without mixing physically with PLA. The averageparticle size was 280.80 ± 0.15 μm, with over 90% of microspheres falling in the range of 250 -390 μm. The encapsulation efficiency was 65.8% ± 0.58% and the drug loading was 34.1% ± 0.51% .In vitro release study revealed a profile of sustained release of Ciprofloxacin from CFX-PLA-MS. Theaccumulated release percentage and half-life (T_(1/2) of Ciprofloxacin microspheres were 84.0% in53.2 h, and 31.9 h, respectively. Higuchi equation was Q= -0.0043 + 0.003 9 t^(1/2), r = 0.9941.Conclusion Ciprofloxacin microspheres have been successfully prepared and sustained release of CFXfrom microspheres is achieved.

Preparation and Effectiveness of Slow-release Polymeric Fertilizer Containing Multiple Nutrients Special for Maize

Slow-release polymeric fertilizer containing multiple nutrients was synthesized through condensation polymerization from raw materials of homemade low-molecular urea-formaldehyde and the compounds of potassium dihydrogen phosphate and phosphoric acid. Adjustment of the proportion of raw materials makes the ingredients of the fertilizer are N:P_2O_5:K_2O =1:0.75:0.13, which satisfy the nutritional requirement for maize growth. Field-experiment results prove that the yield of maize increases by 16.56% when using the polymeric fertilizer special for maize alone, by 56.51% when applying the polymeric fertilizer special for maize plus farmyard manure, and by 49.11% when applying the SV fertilizer special for maize plus manure.

Preparation and Characterization of Potassium Monopersulfate/Ethyl Cellulose Microcapsules and Their Sustained Release Performance

Environmental cleaning is an important aspect of bacteria control.Ethyl cellulose microcapsules containing potassium monopersulfate(PMCM)were prepared by emulsified solvent diffusion method.The chemical structure and microstructure of the obtained PMCM was characterized by methods of Fourier transform infrared spectroscopy(FT-IR),optical microscopy,scanning electron microscopy and X-ACT energy dispersive X-ray spectroscopy.The SEM micrographs of the PMCM containing 21.6%of C,46.8%of O,10.7%of S and 19.4%of K was relatively smooth.Thermal stability,sustained release performance,and antimicrobial activity of PMCM were investigated.The results showed that the drug loading and encapsulation efficiency of PMCM were 30.3%and 42.6%respectively.Potassium monopersulfate was fully released after 8 h,following a Fickian diffusion mechanism.Results showed that the microcapsules prepared with a high concentration of potassium monopersulfate solution showed a good antimicrobial effect.The microcapsule wall of the resulting PMCM increased with increasing ethyl cellulose content and had high thermal stability from the data of 69%residue rate.The excellent thermal stability and high sustained release performance of PMCM showed high application value.

The preparation and the in-vitro pharmacodynamics study of the intracapsular sustained-release preparations for the prevention of posterior capsule opacification

Docetaxel-loaded sustained-release preparation based on 2-Hydroxyethyl methacrylate(HEMA)and Methyl methacrylate(MMA)cross-linked copolymer(P(HEMA-co-MMA))was prepared to examine the potential use for preventing posterior capsule opacification(PCO).The preparations were prepared by polymerizing the mixture of HEMA,MMA,cross-linking agent(EGDMA),initiator(AIBN)and docetaxel.The influence factors and mechanism of drug release were studied in the experiments.FT-IR,X-RD and SEM methods were used to characterize the polymer(P(HEMA-co-MMA))and docetaxel-loaded sustained-release preparations.Biocompatibility of P(HEMA-co-MMA)and in-vitro effect of docetaxel-loaded sustained-release preparations were also evaluated.The results showed that docetaxel could release sustainedly from these preparations prepared by cross-linking polymerization.And the release rate could be accelerated by increasing the MMA ratio or EGDMA ratio of the polymer.Release mechanism of docetaxel fitted the Higuchi model well.The results of IR and X-RD showed that only a hydrogen bond was formed between docetaxel and P(HEMA-co-MMA).Docetaxel dispersed in P(HEMA-co-MMA)in amorphous form.The elution test showed that P(HEMA-co-MMA)had good biocompatibility and the in-vitro pharmacodynamics study proved that docetaxel could release stably from the preparations and inhibit HLECs’proliferation.The docetaxel-loaded sustained-release preparations proved to be a promising therapy for preventing PCO.These results also lay a theoretical and experimental foundation for the future.

Preparation and evaluation of tamsulosin hydrochloride sustained-release pellets modified by two-layered membrane techniques

The aim of the present study was to develop tamsulosin hydrochloride sustained-release pellets using two-layered membrane techniques.Centrifugal granulator and fluidizedbed coater were employed to prepare drug-loaded pellets and to employ two-layered membrane coating respectively.The prepared pellets were evaluated for physicochemical characterization,subjected to differential scanning calorimetry(DSC)and in vitro release of different pH.Different release models and scanning electron microscopy(SEM)were utilized to analyze the release mechanism of Harnual■ and home-made pellets.By comparing the dissolution profiles,the ratio and coating weight gain of Eudragit■ NE30D and Eudragit■ L30D55 which constitute the inside membrane were identified as 18:1 and 10%-11%.The coating amount of outside membrane containing Eudragit■ L30D55 was determined to be 0.8%.The similarity factors(f_(2))of home-made capsule and commercially available product(Harnual■)were above 50 in different dissolution media.DSC studies confirmed that drug and excipients had good compatibility and SEM photographs showed the similarities and differences of coating surface between Harnual■ and self-made pellets before and after dissolution.According to Ritger-Peppas model,the two dosage form had different release mechanism.

Preparation of ozagrel-magnetoliposomes and investigation on the release in vitro under AC-magnetic field

To reduce the first-pass effect and increase the targeting of ozagrel(OZ),the ozagrel -magnetoliposomes(OZ-MLs)were prepared in this study.Here,we described the preparation and characterization of OZ-MLs.It had a diameter of around 0.2μm.To prevent the aggregation of particles,the magnetite was treated with a surfactant,resulting in a stable ferrofluid suspension. The cumulative release of OZ from OZ-MLs could be up to 64.5%in 30 min in vitro under AC-magnetic field.However,it was only 24.0%for OZ-MLs without AC-magnetic field.

Starch Modification for Slow Release of Herbicide Encapsulated with Concentrated Starch Paste

An attempt on starch modification has been made to increase the paste concentration of potato starch for reducing the energy consumption required for the encapsulation of herbicide within starch matrix by encapsulating 2, 4-D as model herbicide. The matrix behaviors were evaluated in terms of the herbicide content, capability of swelling in water, encapsulation efficiency, and the rate of herbicide released from the matrix. To increase paste concentration of starch for decreasing the energy consumption in dry process, potato starch was acidified before the encapsulation. However, the matrix prepared in such a way showed that it weakened the control to the herbicide encapsulated, which increased the rate of herbicide released from the matrix. By introducing covalent bonds among starch molecules, the problem with the control and release rate can be completely solved. Moreover, the effects of formaldehyde amount, medium pH, herbicide content, and particle size on the matrix behaviors and release rate were also investigated. The newly developed matrix shows low capability of swelling and slow release, and reduces water evaporation in dry process by about 40% during matrix preparation.

Innovative color jet 3D printing of levetiracetam personalized paediatric preparations

3D printing is a promising technology used in the fabrication of complex oral dosage delivery pharmaceuticals.This study first reports an innovative color jet 3D printing(CJ-3DP)technology to produce colorful cartoon levetiracetam pediatric preparations with high accuracy and reproducibility.For this study,the ideal printing ink consisted of 40%(v/v)isopropanol aqueous solution containing 0.05%(w/w)polyvinylpyrrolidone and 4%(w/w)glycerin,which was satisfied with scale-up of the production.The external and internal spatial structures of the tablets were designed to control the appearance and release,and cartoon tablets with admirable appearances and immediate release characteristics were printed.The dosage model showed a good linear relationship between the model volume and the tablet strength(r>0.999),which proved the potential of personalized administration.The surface roughness indicated that the appearance of the CJ-3DP tablets was significantly better than the first listed 3D printed drug(Spritam R).Moreover,the scanning electron microscopy and porosity results further showed that the tablets have a structure of loose interior and tight exterior,which could ensure good mechanical properties and rapid dispersion characteristics simultaneously.In conclusion,the innovative CJ-3DP technology can be used to fabricate personalized pediatric preparations for improved compliance.Due to the stable formulation and fabrication process,this technology has the potential in scale-up production.

Preparation and quality evaluation of vincristine sulfate-loaded PEG-PLGA nanoparticles

Objective To prepare the PEG-PLGA nanoparticles loaded with vincristine sulfate(VCR-loaded PEG-PLGA-NPs) and evaluate their quality.Methods VCR-loaded PEG-PLGA-NPs were prepared by the double emulsion solvent evaporation method.The main experimental factors,which influenced the physical and chemical properties of the nanoparticles,were investigated and optimized.Results Under optimal conditions,the VCR-loaded PEG-PLGA-NPs had an average diameter of 135.9 nm with narrow size distribution.The encapsulation efficiency was 68.2%,while the drug loading capacity was 8.34%.In vitro,VCR was released from the PEG-PLGA-NPs sustainedly for more than 13 days with the total amount of 81%.Moreover,the VCR-loaded PEG-PLGA-NPs were relatively stable,which was confirmed by the stability testing.Conclusion The VCR-loaded PEG-PLGA-NPs are a promising nano drug with controlled release,which can be applied widely.

Preparation, optimization and in vitro–in vivo investigation for capsules of the choline salt of febuxostat

The objective of the present study was to exhibit the enhanced water-solubility and in vivo oral absorption when febuxostat(FXT) became the salt formation of choline. The formation of the choline salt of febuxostat was confirmed by X-ray powder diffraction, infrared spectroscopy analysis and differential scanning calorimetry. The direct filling method was used to develop a capsule formulation. Cellactose 80 was used as the filler due to its good fluidity, while cross-linked polyvinylpyrrolidone(PVPP) and magnesium stearate(MS) were used as the disintegrant and lubricant, respectively. Then the in vitro release of the formulation was carried out in five different dissolution media including HCl solution(pH 1.2),acetate buffer(pH 4.5), phosphate buffer(pH 6.8 and pH 7.2) and water. Evident improvement of release for choline febuxostat(CXT) was presented in water while the dissolution degree was decreased for CXT in the medium of phosphate buffer(pH 6.8) in comparison with FXT. Furthermore, the pharmacokinetics of CXT was studied in rats using UPLC-MS/MS compared with FXT. The data acquired illustrated that AUC0-24 h of CXT and FXT were22,245.96 ± 7342.92 μg·h/l and 12,249.70 ± 2024.04 μg·h/l, respectively. The relative bioavailability of CXT to FXT was about 181.6% and the P value of AUC0-24 h was less than 0.05. It showed significant difference between the two drugs after oral administration. In conclusion, the water-solubility and oral bioavailability were both improved remarkably for the choline salt of febuxostat and choline salinization was proved an effective way to increase the in vivo absorption for FXT.

Correction: Spontaneous apoptosis of cells in therapeutic stemcell preparation exert immunomodulatory effects throughrelease of phosphatidylserine

After online publication of the article1,the authors noticed one inadvertent mistake in Fig.5a that needs to be corrected.In detail,the pathological picture of PBS group in Fig.5a is inadvertently duplicated as the image of PBS group in Fig.7b in the main text.This duplication is a result of errors in figure assembly,and the correct Fig.5 is provided as follows.The key findings of the article are not affected by these corrections.

缓控释肥硅基膜材的制备与表征

以钙镁磷肥、硅丙树脂为主要原料,加入甲基硅酸钠作粘结剂,制备了缓控释肥硅基膜材,并采用撒粉离心包衣、底喷式流化床工艺制备了密封型硅钙镁磷肥、粘结型硅钙镁磷肥、改性硅丙树脂3种包膜尿素,通过静水试验研究了此3种包膜尿素的释放特征。结果表明,3种包膜尿素的释放周期分别为60、79、96 d,在水中均能保持完整球形,耐水性较好。通过扫描电镜、红外光谱、X-射线衍射法对膜材形貌特征和结构进行表征,发现钙镁磷肥和硅丙树脂为成膜材料;甲基硅酸钠作为密封剂和防水剂参与了成膜反应,有效增加了膜材的塑性和韧性,此复合材料可用作缓控释肥的胶结剂和包膜剂。

基于反溶剂结晶法制备姜黄素纳米微粉

为了研究和确定反溶剂结晶法制备姜黄素纳米微粉的处方及工艺,文章以粒径、释放曲线、收率等为考察指标,确定溶剂种类、溶液浓度、搅拌方式、溶剂反溶剂体积比、反应温度、喷液速度、表面活性剂种类、放置时间等参数,通过正交试验对处方进行优化,并进行高温、高湿及光照试验,验证纳米微粉的稳定性。结果显示最佳工艺是姜黄素乙醇溶液浓度为5 mg/mL,以Poloxamer188的水溶液作为反溶剂,溶剂与反溶体积比为1:5,反溶剂55℃,以1.0 mL/min喷入姜黄素溶液,以超声振荡器进行混合,混匀后放置8h,分离,减压干燥;稳定性试验结果表明,纳米微粉在高温及光照条件下性状及释放性能稳定,高湿条件下易结块,释放度显著降低。

眼用曲安奈德微球的制备工艺优化及体外释放研究

目的:研究眼用曲安奈德微球的制备工艺优化及体外释放方法。方法:采用超声乳化、减压蒸发、冷冻干燥法制备聚乳酸-羟基乙酸共聚物(PLGA)/曲安奈德(TA)微球,优化制备工艺并进行体外药物释放研究。结果:TA/PLGA投料比为30∶70,二氯甲烷/乙酸乙酯为50∶50,PLGA比例(分子量a∶b)为75∶25,PLGA投料量为1500 mg,乳化剂浓度为1%是最佳工艺参数。PLGA-TA微球释放的实时药物浓度和累积释放率低于TA原料药,差异有统计学意义(P<0.05)。结论:与TA原料药相比,PLGA-TA微球的药物释放速率较慢,表现出良好的缓释性能,为后续开展体内研究提供了体外数据支持。

抗晕动病药物及其缓控释制剂的研究进展

晕动病是指机体在异常运动下受到刺激而引起的一系列生理反应,常见症状有头晕、呕吐等。目前,抗晕动病药物主要有抗组胺药、抗胆碱药、钙拮抗药、拟交感神经药、胃动力药,且多数为普通制剂,而缓控释制剂的研发及应用较少。本文对晕动病的发病机制、治疗药物分类以及抗晕动病药物缓控释制剂,如透皮制剂、鼻用制剂和口服制剂的研究进展进行综述,分析目前晕动病防治研究过程中存在的问题,为抗晕动病药物新剂型的研发提供新思路。

白屈菜总生物碱缓释片制备工艺研究

目的:以羟丙基甲基纤维素为缓释材料制备白屈菜总生物碱缓释薄膜衣片解决白屈菜有效成分药物浓度不稳定的缺点,并建立可靠的含量测定方法。方法:采用单因素实验对白屈菜总碱缓释薄膜衣片制备工艺进行筛选,以释放度为依据;采用高效液相色谱法(HPLC)建立了白屈菜总碱缓释薄膜衣片中血根碱的含量测定方法。结果:优化的缓释片工艺处方:30%白屈菜总碱提取物、30%HPMC、20%可压性淀粉、10%乳糖、10%微晶纤维素,挤压制粒,加1%硬脂酸镁,压片,即得。结论:该工艺制得白屈菜总碱缓释片释药曲线平缓,缓释效果良好,方法简单易行,所得薄膜衣片外观和可压性良好。

马铃薯淀粉膜制备工艺优化及活性包装中百里香酚释放动力学

为提高食品包装中抑菌剂百里香酚(thymol,THY)的生物利用率以延长食品的货架期,该研究采用介孔二氧化硅(mobil composition of matter No. 41,MCM-41)作为THY的控释载体(THY-MCM-41),以马铃薯淀粉为原料制备马铃薯淀粉活性包装膜。利用L_(9)(3^(4))正交试验探究马铃薯淀粉、甘油、氯化钙和THY-MCM-41质量浓度对包装膜机械、物理以及水蒸气阻隔性能的交互影响,优化马铃薯淀粉活性包装膜最佳制备工艺参数,并在不同储存环境下对最优组合活性包装膜中百里香酚的释放动力学进行研究,构建百里香酚释放预测模型。结果表明,当马铃薯淀粉质量浓度为0.04 g/mL,甘油质量浓度为0.015 g/mL,氯化钙质量浓度为0.005 g/mL,THY-MCM-41质量浓度为0.005 g/mL时,制备的包装膜A综合性能最优,其抗拉强度、溶胀度、水蒸气透过率、透氧性和不透明度分别为7.16 MPa、89.23%、1.42×10^(-10)g/(m·s·Pa)、1.02×10^(-15)cm^(2)/(s·Pa)和1.16 mm^(-1)。电子扫描电镜和傅里叶红外光谱分析均证实了THY-MCM-41均匀地分散在马铃薯淀粉膜中,与马铃薯淀粉之间具有良好的相容性。马铃薯淀粉活性包装膜可控制百里香酚的释放速率,将百里香酚的有效作用时间延长到10 d。其中,百里香酚的释放规律符合一级释放模型(R^(2)> 0.980),其释放行为遵循菲克扩散定律。该研究为智能活性包装膜中活性物质的精准控释提供了理论基础。

叶酸修饰的粉防己碱壳聚糖-硬脂酸纳米胶束的制备、表征及体外抗炎活性考察

目的制备叶酸(FA)修饰的粉防己碱(TET)壳聚糖(CS)-硬脂酸(SA)纳米胶束(简称“FA-CS-SA/TET纳米胶束”),并进行表征和体外抗炎活性考察。方法采用超声法制备FA-CS-SA/TET纳米胶束,以包封率(EE)、载药量(DL)、粒径的综合评分为评价指标,FA-CS-SA与TET质量比、超声功率和超声次数为考察因素,根据正交实验确定最优制备工艺并验证;对以最优工艺制备的FA-CS-SA/TET纳米胶束进行表征,并考察其体外释放性能。以RAW264.7细胞为实验对象,考察其体外抗炎活性。结果最优制备工艺为FA-CS-SA与TET质量比2∶1,超声功率200W,超声200次。以最优工艺制备的FA-CS-SA/TET纳米胶束的EE为(98.86±0.30)%,DL为(28.57±0.34)%,平均粒径为(227.0±9.4)nm,多分散性指数为0.42±0.04,Zeta电位为(12.6±2.3)mV;该纳米胶束呈类圆形且分布均匀,其在0.5%十二烷基硫酸钠溶液中释放较快,72h内的累积释放度为(79.49±3.43)%,且其抗炎作用强于TET原料药。结论本研究成功制备了FA-CS-SA/TET纳米胶束,其载药性能良好,粒径均匀,且具有较好的体外抗炎活性。

缓释氧材料在河湖水体污染修复中的应用研究进展

投加增氧剂作为一种提升水体溶解氧的重要手段常用于城市水环境的治理与修复,研发具有缓释效果的增氧材料可使增氧剂在实际工程中更持久、更稳定地发挥作用.本文梳理了近年来缓释氧材料的制备方法和释氧性能,综述了投加缓释氧材料对河湖沉积物和上覆水中营养盐等污染物赋存形态与迁移转化的影响及作用机制,最后对缓释氧材料在河湖水体污染修复中的应用研究提出了展望和建议.

大黄素甲醚微囊缓释剂的制备及表征

制备一种大黄素甲醚微囊缓释剂,将大黄素甲醚制成微乳液,提高其溶解度,进一步采用原位聚合法,以密胺树脂作为囊壁,将大黄素甲醚微乳液微囊化。微乳液中大黄素甲醚的溶解度约为5 g/L,明显高于在其他溶剂中溶解度。当囊芯为微乳液(含水量30%),密胺树脂为囊壁,芯壁比(质量比)为3∶1时,所制大黄素甲醚微囊缓释剂的载药量和包封率最高,在水中14 d累积释放率为72.0%,土壤中35 d累积释放率为51.9%。该微囊缓释剂分布均匀、载药量高、释药缓慢持久,用于病害防控可减少给药次数,具有重要的实际应用价值。