超临界流体技术制备微细颗粒的方法及装置

综述三种重要的超临界流体技术制备微细颗粒的方法:超临界流体快速膨胀法、超临界流体抗溶剂法及气体饱和溶液沉析法,对这三种颗粒制备方法的工艺原理、装置及其各自的特点进行了比较,并对超临界流体技术制备微细颗粒中存在的问题和发展前景进行了分析和展望。     

气体抗溶剂结晶技术的初步研究

建立气体抗溶剂结晶实验装置，并用该套实验装置对柠檬酸(CA)的气体抗溶剂结晶进行了研究。考察了不同操作条件下(温度、水含量、进料浓度)压力对柠檬酸丙酮溶液的溶解度的影响规律，并得到了晶体，对比了条件变化对晶体颗粒的粒径大小和分布的影响。试验证明气体抗溶剂结晶技术在制备微细颗粒领域内具有广阔的应用前景。     

超临界过程参数对药物微粉化的影响

概述了超临界溶液快速膨胀(RESS)法和超临界抗溶剂(SAS)过程及其衍生方法的基本原理,以及工艺参数对药物微粉化的影响.介绍了RESS、SAS及其衍生技术在制备固体药物细微颗粒方面的应用前景.     

超临界CO2抗溶剂法制备谷维素/PVP-K30固体分散体

目的制备谷维素/PVP-K30固体分散体,提高谷维素的体外溶出度。方法采用超临界CO2抗溶剂法,以回收率为主要评价指标,在单因素试验的基础上设计正交试验优选制备谷维素/PVP-K30固体分散体的工艺,对最优工艺下得到的复合物进行红外光谱(IR)及扫描电镜(SEM)的表征,并测定其体外溶出度。结果制备谷维素/PVP-K30的最优工艺为:谷维素质量浓度14 mg/m L,结晶压力14 MPa,结晶温度55℃,溶液体积流量0.9 m L/min。此条件下产品平均回收率为88.22%,IR和SEM表明固体分散体中谷维素可能与PVP-K30发生氢键作用并以无定型形式存在,体外溶出度实验表明谷维素/PVP-K30固体分散体能显著提高谷维素的体外溶出度。结论超临界CO2抗溶剂法制备维素/PVP-K30固体分散体工艺可行,谷维素溶出度显著提高。     

超临界流体技术在抗生素类药物微粒制备中的应用

综述了超临界流体技术在抗生素行业中的新研究成果和应用概况：不论在抗生素类药物微粒制备或在其提取工艺中都应重视溶解度的基础研究。着重介绍了超临界溶液快速膨胀和超临界抗溶剂工艺在抗生物微粒制备中的进展。所得实例显示出超临界流体技术在抗生索微粒制备中的潜在优势和进一步拓展其应用的良好前景。     

超临界流体抗溶剂结晶技术在药物制粒领域中的应用

概述超临界流体的物性及其结晶操作特性和超临界流体抗溶剂过程的机制与操作方式以及在药物制粒领域中的应用，其中包括生物药品和抗生素药品的制粒及药物复合微球和微囊的制备。     

超临界CO2抗溶剂法制备布洛芬/EC-PVP缓释复合微粒

采用超临界CO2抗溶剂法制备具有缓释效果的布洛芬/乙基纤维素(EC)-聚乙烯醇吡咯烷酮(PVP)复合微粒。以载药量为主要评价指标,采用正交试验设计优选布洛芬/EC-PVP复合微粒的制备工艺,并对优选的工艺组合进行了包封率、粒径分布、电镜分析、红外光谱(IR)、差示扫描量热法(DSC)以及体外溶出等实验分析。正交试验得到的优选工艺为:结晶温度40℃,结晶压力12 MPa,PVP质量浓度4 mg.mL/1,动态CO2流出速度3.5 L.min?1。此工艺条件下,制备得到的复合微粒的载药量和包封率分别为12.14%和52.21%,平均粒径为27.621μm;IR与DSC分析表明PVP与EC可能发生了络合反应;体外溶出实验表明布洛芬/EC-PVP复合微粒具有良好的缓释效果。实验表明,超临界CO2抗溶剂法可制备具有缓释效果的布洛芬/EC-PVP复合微粒。     

超临界流体技术在药学领域制备微粒中的应用

超临界流体在体系中可分别作为溶剂、抗溶剂、溶质，本文综述了近年来超临界流体技术用于制备微粒（如纳米粒、微球、脂质体、固体分散体等）的装置原理、工艺以及在药学领域中的研究进展。     

超临界流体制备超细微粒技术及其在药物制剂方面的应用

介绍了超临界溶液快速膨胀法，超临界流体抗溶剂法，超临界流反应法，超临界逆向结晶法及超临界干燥法等制细技术的基本原理，以及它们在药物制剂方面的应用。     

超临界抗溶剂技术在药物微粒制备领域中的应用

超临界抗溶剂(SAS)技术是一种新型的微粒制备技术。本文介绍了SAS技术的基本原理和操作方式,综述了近年来SAS技术在药物微粒制备领域中包括制备药物超细微粒和药用复合微粒两个方面的应用,并展望了SAS技术在药物微粒制备领域中的主要研究前景。     

Characteristics of Rofecoxib-Polyethylene Glycol 4000 Solid Dispersions and Tablets Based on Solid Dispersions

The aim of this work was to report the properties of rofecoxib-PEG 4000 solid dispersions and tablets prepared using rofecoxib solid dispersions. Rofecoxib is a poorly water soluble nonsteroidal anti-inflammatory drug with a poor dissolution profile. This work investigated the possibility of developing rofecoxib tablets, allowing fast, reproducible, and complete rofecoxib dissolution, by using rofecoxib solid dispersion in polyethylene glycol (PEG) 4000. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the solid state of solid dispersions. The effect of PEG 4000 concentration on the dissolution rate of rofecoxib from its solid dispersions was investigated. The dissolution rate of rofecoxib from its solid dispersions increased with an increasing amount of PEG 4000. The extent of dissolution rate enhancement was estimated by calculating the mean dissolution time (MDT) values. The MDT of rofecoxib decreased significantly after preparing its solid dispersions with PEG 4000. The FTIR spectroscopic studies showed the stability of rofecoxib and absence of well-defined rofecoxib-PEG 4000 interaction. The DSC and XRD studies indicated the amorphous state of rofecoxib in solid dispersions of rofecoxib with PEG 4000. SEM pictures showed the formation of effective solid dispersions of rofecoxib with PEG 4000 since well-defined change in the surface nature of rofecoxib and solid dispersions were observed. Solid dispersions formulation with highest drug dissolution rate (rofecoxib: PEG 4000 1:10 ratio) was used for the preparation of solid dispersion–based rofecoxib tablets by the direct compression method. Solid dispersion–based rofecoxib tablets obtained by direct compression, with a hardness of 8.1 Kp exhibited rapid drug dissolution and produced quick anti-inflammatory activity when compared to conventional tablets containing pure rofecoxib at the same drug dosage. This indicated that the improved dissolution rate and quick anti-inflammatory activity of rofecoxib can be obtained from its solid dispersion–based oral tablets.     

A calorimetric investigation into the interaction between paracetamol and polyethlene glycol 4000 in physical mixes and solid dispersions.

The solubility, heat of solution and dissolution rate of paracetamol and polyethyelene glycol 4000 (PEG 4000) systems have been studied in order to clarify the nature of the interaction between the two components during dissolution of solid dispersions. The logarithmic solubility of paracetamol demonstrated a non-linear increase with concentration of PEG 4000, while linear relationships between heat of solution in water and concentration were seen for both individual components. However, the heat of solution of paracetamol was found to decrease with increasing concentrations of PEG 4000. Similarly, the heats of solution in water of physical mixes and solid dispersions prepared using two manufacturing protocols were found to be lower than the theoretical values calculated from those corresponding to the individual components. Drug release studies showed a marked increase in paracetamol dissolution rate when prepared as a solid dispersion, with behaviour consistent with carrier controlled dissolution observed at low drug contents which was ascribed to enhanced dissolution of the drug into the diffusion layer of the PEG 4000. The implications of the understanding of this mechanism for the choice of carrier and manufacturing protocol for solid dispersion products is discussed.     

Preparation and characterization of solid dispersions of Quercetin with PEG4000

Objective To enhance the solubility,quicken the speed of digesting and absorption,and increase the bioavailability of quercetin(3,3',4',5,7-pentahydroxyflavone).Methods A series of Quercetin-PEG4000 solid dispersions were prepared by fusion method.The configuration and property of solid dispersion were characterized by solubility tests,dissolution tests,FTIR spectra,differential scanning calorimetry(DSC)and microphotograph.Results 1.According to solubility tests the the mass ratio of quercetin to PEG4000 affected strongly on the solubility of solid dispersions,on the whole,the relation of the solubility of solid dispersions to the mass ratio presented linear relationship.The preparation temperature had little effect on the solubility of solid dispersions.The surface-active agent,polysorbate80 increased strongly the solubility of solid dispersions.2.According to the dissolution tests,the mass ratio of quercetin to PEG4000 affected strongly on the dissolution of solid dispersions,the preparation temperature had little effect on the dissolution of solid dispersions.The surface-active agent,polysorbate80 increased strongly the dissolution of solid dispersions,and after addition polysorbate80,the dissolution of solid dispersions was two times of the dissolution of solid dispersions without polysorbate80.3.According to the DSC results,except that a little of quercetin molecular existed as crystalline state in the solid dispersion with the mass ratio was qu:PEG=1:2,quercetin existed as amorphous phase in other mass ratio solid dispersion.4.According to the FTIR spectra and microphotograph results,the relation of quercetin and PEG4000 was mainly physical mixing in quercetin-PEG4000 solid dispersion.Quercetin was just like solute in solution,and PEG4000 was just like solvent in solution.The force between quercetin and PEG4000 was mainly hydrogen bonding,so the biological activity of quercetin would not be influenced greatly after the formation solid dispersion.Conclusions These results suggest that quercetin existed mainly as amorphous phase in solid dispersion;the solubility and the dissolution in water were increased obviously after formation the solid dispersion.     

Characteristics of rofecoxib-polyethylene glycol 4000 solid dispersions and tablets based on solid dispersions

The aim of this work was to report the properties of rofecoxib-PEG 4000 solid dispersions and tablets prepared using rofecoxib solid dispersions. Rofecoxib is a poorly water soluble nonsteroidal anti-inflammatory drug with a poor dissolution profile. This work investigated the possibility of developing rofecoxib tablets, allowing fast, reproducible, and complete rofecoxib dissolution, by using rofecoxib solid dispersion in polyethylene glycol (PEG) 4000. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the solid state of solid dispersions. The effect of PEG 4000 concentration on the dissolution rate of rofecoxib from its solid dispersions was investigated. The dissolution rate of rofecoxib from its solid dispersions increased with an increasing amount of PEG 4000. The extent of dissolution rate enhancement was estimated by calculating the mean dissolution time (MDT) values. The MDT of rofecoxib decreased significantly after preparing its solid dispersions with PEG 4000. The FTIR spectroscopic studies showed the stability of rofecoxib and absence of well-defined rofecoxib-PEG 4000 interaction. The DSC and XRD studies indicated the amorphous state of rofecoxib in solid dispersions of rofecoxib with PEG 4000. SEM pictures showed the formation of effective solid dispersions of rofecoxib with PEG 4000 since well-defined change in the surface nature of rofecoxib and solid dispersions were observed. Solid dispersions formulation with highest drug dissolution rate (rofecoxib: PEG 4000 1:10 ratio) was used for the preparation of solid dispersion-based rofecoxib tablets by the direct compression method. Solid dispersion-based rofecoxib tablets obtained by direct compression, with a hardness of 8.1 Kp exhibited rapid drug dissolution and produced quick anti-inflammatory activity when compared to conventional tablets containing pure rofecoxib at the same drug dosage. This indicated that the improved dissolution rate and quick anti-inflammatory activity of rofecoxib can be obtained from its solid dispersion-based oral tablets.     

An investigation into the production of paracetamol solid dispersions in PEG 4000 using hot stage differential interference contrast microscopy

The melting and crystallisation behaviour of paracetamol dispersions in polyethylene glycol (PEG) 4000 has been studied using differential interference contrast microscopy fitted with a hot stage. The effects of thermally cycling physical mixes of the two components have been studied with particular reference to the effects of the presence of molten PEG 4000 on the melting behaviour of the model drug. The effects of the drug particle size, the maximum temperature of heating and the holding time at the maximum temperature on the solid dispersion structure have been investigated, with profound changes in structure being observed depending on the manufacturing protocol used. In particular, higher maximum temperatures and holding times with lower drug particle sizes promoted greater dissolution of the drug into the molten PEG. In the majority of systems observed, the remaining paracetamol particles simply persisted as the system was cooled. However, for certain systems, involving high drug loadings and extended holding times and temperatures in the liquid state, the drug recrystallised over a 24-h period to form a fine dispersion within the carrier. The study has therefore demonstrated the usefulness of hot stage microscopy as a method of directly observing the processes involved during the manufacture of solid dispersions and has also indicated that changing the manufacturing protocol may have a profound effect on the structure of the dispersion.     

Preparation of esomeprazole zinc solid dispersion and study on its pharmacokinetics

Esomeprazole zinc (EZ) is a poorly water-soluble substance. In order to increase its dissolution rate and bioavailability, solid dispersions of esomeprazole zinc (SDEZ) in polyethylene glycol 4000 (PEG4000) with different EZ to PEG4000 ratios were prepared by solvent method. Our studies showed that dissolution rate of EZ were distinctively increased in the solid dispersion system compared to that in pure EZ or physical mixtures. The increase of dissolution rate was obviously related to the ratio of EZ to PEG4000. The solid dispersion system (EZ/PEG4000=1/8, w/w) gave the highest dissolution rate: about 14.7-fold higher than that of the pure EZ. EZ was proved to be in amorphous state in this solid dispersion by using differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) techniques. In vivo administration studies, SDEZ in enteric capsule (SDEZ-EC) has a lower Cmax and a longer Tmax than that of esomeprazole magnesium enteric-coated tablet (Nexium), and the differences of Cmax and Tmax between SDEZ-EC and Nexium are significant. This result suggests SDEZ-EC has a lower absorption rate than Nexium and corresponds with the in vitro dissolution.     

Solid dispersion of meloxicam: factorially designed dosage form for geriatric population

The objective of the present work was to improve the dissolution properties of the poorly water-soluble drug meloxicam by preparing solid dispersions with hydroxyethyl cellulose (HEC), mannitol and polyethylene glycol (PEG) 4000 and to develop a dosage form for geriatric population. Differential scanning calorimetry, X-ray diffractometry, Fourier transform infrared spectroscopy and scanning electron microscopy were used to investigate the solid-state physical structure of the prepared solid dispersions. Higher in vitro dissolution of solid dispersions was recorded compared to their corresponding physical mixtures and the pure drug. PEG 4000 in 1: 9 drug to carrier ratio exhibited the highest drug release (100.2%), followed by mannitol (98.2%) and HEC (89.5%) in the same ratio. Meloxicam-PEG 4000 solid dispersion was formulated into suspension and optimization was carried out by 23 factorial design. Formulations containing higher levels of methyl cellulose and higher levels of either sodium citrate or Tween 80 exhibited the highest drug release.     

替硝唑固体分散体的制备及其体外释放特性研究

目的:利用固体分散技术制备替硝唑固体分散体,增加替硝唑溶解度和溶出速度。方法:以聚乙二醇(PEG)为载体材料,采用溶剂-熔融法制成固体分散体,测定表观溶解度,进行体外溶出试验,并采用差示扫描量热(DSC)法鉴别药物在固体分散体中的存在状态。结果:替硝唑的溶出度和表观溶解度随PEG的比例不同而不同,且溶出度随载体用量增加而增加。固体分散体的DSC曲线中替硝唑药物的特征熔融峰消失。结论:所制得的固体分散体能明显提高替硝唑的溶出度和表观溶解度。     

Relating solubility data of parabens in liquid PEG 400 to the behaviour of PEG 4000-parabens solid dispersions

The solid state behaviour of polyethylene glycol 4000 (PEG 4000) and dispersions of a homologous series of parabens (methyl- (MP), ethyl- (EP), propyl- (PP) and butyl- (BP)) were examined and compared to the paraben solubility in liquid PEG 400. Dispersions were prepared by co-melting different amounts of paraben (5–80% (w/w)) and PEG 4000 and were studied using a combination of differential scanning calorimetry (DSC) and small and wide angle X-ray diffraction (SAXD/WAXD). Depending on the concentration of parabens in the dispersions, DSC showed melting peaks from folded and unfolded forms of PEG, a eutectic melting and melting of pure parabens. The fraction of folded PEG increased and the melting temperatures of both PEG forms decreased with increasing paraben content. In an apparent phase diagram of PP–PEG dispersions a eutectic mixture appeared above 5% PP. In addition, a melting peak corresponding to the paraben appeared for dispersion containing more than 60% PP. Similar phase diagrams were shown for the other parabens. The SAXD data and a 1D correlation function analysis revealed that MP and BP were incorporated into the amorphous domains of the lamellae of solid PEG to a higher degree than EP and PP. In addition, the lamellae thickness of PEG and the fraction of amorphous domains increased more for MP and BP compared to EP and PP. BP showed the highest solubility of the parabens followed by MP, EP and PP in both liquid and solid PEG. Furthermore, the thickness of the amorphous domains of the PEG in the different parabens–PEG dispersions could be correlated to the solubility in liquid PEG 400.     

Physical Stability of Solid Dispersions Containing Triamterene or Temazepam in Polyethylene Glycols

The effect of storage on the physical stability of solid dispersions of triamterene or temazepam in polyethylene glycols was studied using differential scanning calorimetry (DSC), particle-size analysis and dissolution methods. The enthalpies of fusion of the carriers, without included drug and previously fused and crystallized, increased on storage. Analysis of similarly treated solid dispersions, containing either 10% temazepam or 10% triamterene, showed that each drug influenced the morphology of the polyethylene glycol (PEG). The enthalpies and melting points of the solidus components of the dispersions' carriers were initially reduced after preparation, but on storage these increased. The particle sizes of the drugs dispersed in the PEGs increased on storage. The changes in dissolution after storage of triamterene or temazepam dispersions were smaller for dispersions in PEG 1500 than for dispersions in PEGs of higher molecular weight (PEG 2000, PEG 4000 or PEG 6000) in which the reduction in dissolution was particularly marked during the first month of storage. The rank order of changes in dissolution were PEG 1500 ? PEG 2000 < PEG 4000 ～ PEG 6000.