药物超细微粒制备技术的概述

超细微粒制备技术已在药物制剂领域被广泛深入地研究和应用。本文重点介绍了喷雾干燥、冷冻真空干燥、超微粉碎研磨、超声粉碎、高压均质技术及超临界CO2技术的原理及在药物细化方面的应用。     

The preparation of sustained release erythropoietin microparticle

Purpose: Protein microencapsulation in biodegradable polymers is a promising route to provide for sustained release. The erythropoietin (EPO) microparticles are using human serum albumin (HSA) and poly-L-lysine (PK) as the protection complex to increased EPO integrity, entrapped efficiency and active EPO release by w/o/w solvent evaporation techniques. The optimum formulation development process was also reported by using FITC-OVA as a model protein.

Methods: The model protein FITC-ovalbumin and EPO are protected by human serum albumin and poly-L-lysine complex and encapsulated in 50:50 poly(DL-lactide-co-glycolide) by a w/o/w solvent evaporation method. Protein active integrity and degradation compound is measured by size-exclusion chromatography. Protein-loaded microparticle physical properties and in vitro active and degradation compounds release profile are characterized.

Results: High active integrity protein loading efficiency and particle yield of EPO or OVA-HSA/PK-loaded PLG microparticles are successfully produced by a w/o/w solvent evaporation method. Varied protection protein complex formulations and encapsulation processes are investigated. The high OVA model protein loading efficiency (80.2%), FITC-OVA content (0.24?µg?mg^?1) and yield (72.4%) are obtained by adding 100?µg?mL^?1 FITC-OVA complex with 10% HSA/0.05% PK (Mw 1.5–3?kD) in the initial solution to protect the model protein. In vitro release profiles show more active OVA release from HSA/PK OVA-loaded than OVA-loaded only microparticles and also the amount of degraded protein that comes out after 3 weeks incubated in the PBS medium for OVA-loaded only microparticles is observed. The same formulation and preparation process resulted in EPO loading efficiency (68.4%), EPO content (0.23?µg?mg^?1) and yield (76.1%) for HSA/PK EPO-loaded microparticles. In vitro release profiles show active EPO sustained release over 7 days. Using HSA/PK as carried in the primary emulsion of EPO-loaded microparticles resulted in less burst release% than EPO-loaded only microparticles.     

The preparation of sustained release erythropoietin microparticle

PURPOSE: Protein microencapsulation in biodegradable polymers is a promising route to provide for sustained release. The erythropoietin (EPO) microparticles are using human serum albumin (HSA) and poly-L-lysine (PK) as the protection complex to increased EPO integrity, entrapped efficiency and active EPO release by w/o/w solvent evaporation techniques. The optimum formulation development process was also reported by using FITC-OVA as a model protein. METHODS: The model protein FITC-ovalbumin and EPO are protected by human serum albumin and poly-L-lysine complex and encapsulated in 50:50 poly(DL-lactide-co-glycolide) by a w/o/w solvent evaporation method. Protein active integrity and degradation compound is measured by size-exclusion chromatography. Protein-loaded microparticle physical properties and in vitro active and degradation compounds release profile are characterized. RESULTS: High active integrity protein loading efficiency and particle yield of EPO or OVA-HSA/PK-loaded PLG microparticles are successfully produced by a w/o/w solvent evaporation method. Varied protection protein complex formulations and encapsulation processes are investigated. The high OVA model protein loading efficiency (80.2%), FITC-OVA content (0.24 microg mg(-1)) and yield (72.4%) are obtained by adding 100 microg mL(-1) FITC-OVA complex with 10% HSA/0.05% PK (Mw 1.5-3 kD) in the initial solution to protect the model protein. In vitro release profiles show more active OVA release from HSA/PK OVA-loaded than OVA-loaded only microparticles and also the amount of degraded protein that comes out after 3 weeks incubated in the PBS medium for OVA-loaded only microparticles is observed. The same formulation and preparation process resulted in EPO loading efficiency (68.4%), EPO content (0.23 microg mg(-1)) and yield (76.1%) for HSA/PK EPO-loaded microparticles. In vitro release profiles show active EPO sustained release over 7 days. Using HSA/PK as carried in the primary emulsion of EPO-loaded microparticles resulted in less burst release% than EPO-loaded only microparticles.     

Chitosan microparticle preparation for controlled drug release by response surface methodology

The objectives were to investigate the effects of formulation variables on the release of drug and to optimize the formulation of chitosan microparticles loaded with drug for controlled release using response surface methodology. Chitosan microparticles were prepared by dropping a chitosan solution into sodium tripolyphosphate (TPP) through ionic cross-linking. The release behaviour of felodipine as a model drug was affected by preparation variables. A central composite design was used to evaluate and optimize the effect of preparation variables, chitosan concentration (X1), the pH of the TPP solution (X2) and cross-linking time (X3) on the cumulative per cent drug release (Y) in 24 h. Chitosan concentration and cross-linking time affected negatively the release of felodipine, while the pH of the TPP did so positively and was the highest influential factor. The optimum rate of drug release, 100% in 24 h, was achieved at 1.8% chitosan concentration, a pH 8.7 for the TPP solution and 9.7 min cross-linking time.     

Chitosan microparticle preparation for controlled drug release by response surface methodology

The objectives were to investigate the effects of formulation variables on the release of drug and to optimize the formulation of chitosan microparticles loaded with drug for controlled release using response surface methodology. Chitosan microparticles were prepared by dropping a chitosan solution into sodium tripolyphosphate (TPP) through ionic cross-linking. The release behaviour of felodipine as a model drug was affected by preparation variables. A central composite design was used to evaluate and optimize the effect of preparation variables, chitosan concentration (X₁), the pH of the TPP solution (X₂) and cross-linking time (X₃) on the cumulative per cent drug release (Y) in 24 h. Chitosan concentration and cross-linking time affected negatively the release of felodipine, while the pH of the TPP did so positively and was the highest influential factor. The optimum rate of drug release, 100% in 24 h, was achieved at 1.8% chitosan concentration, a pH 8.7 for the TPP solution and 9.7 min cross-linking time.     

Electromembrane extraction: a new technique for accelerating bioanalytical sample preparation

The recent societal requirements to explore more environmentaly friendly solutions in the field of sample preparation have gained increasing focus during recent years. A reduction in the consumption of hazardous organic solvent owing to environmental and cost perspectives, small amounts of sample available and time reduction, have been major incentives for scientists to miniaturize existing sample preparation methods. Some of these challenges were addressed by the introduction of electromembrane extraction (EME), a totally new extraction principle where a potential difference is applied across a thin organic membrane immobilized in the pores in the wall of a porous polypropylene membrane. The potential difference is utilized to extract charged analytes of interest from the sample, across the organic membrane, and into an aqueous acceptor solution present inside the lumen of the hollow fiber. This article focuses on the potential of EME in bioanalysis, including discussions of EME performance.     

Horizontal diffusion elutriation: a new size-separation technique for preparation of rodent-respirable fibers for animal testing

Short-and long-term animal experiments are used to examine the toxicology and biopersistence of various types of fibers. In order to ensure an adequate exposure dose for testing, modern experimental protocols specify that the exposure aerosol (in an inhalation test) or the fibers (in an intratracheal instillation [IT] test) must contain at least a minimum concentration of long (> 20 mum) rodent-respirable fibers. As produced and handled, most fibers contain a distribution of diameters and lengths, only some of which are both long and rodent-respirable. Therefore, it is necessary to size-separate the fibers to enrich the proportion of long, rodent-respirable fibers in the material to be tested. This article presents a new and relatively simple method for size separation that avoids some of the difficulties associated with other methods. The method, termed horizontal diffusion elutriation (HDE), is illustrated by size-separating refractory ceramic fiber (RCF) and four polycrystalline alumina (PCA) fibers.     

脱乙酰甲壳质的制备工艺改进

目的对从虾蛄壳中提取制备脱乙酰甲壳质的传统工艺进行改进。方法通过改变制备条件和步骤,改进工艺,并与传统工艺进行比较。结果改进的制备工艺较传统工艺操作条件更温和,所得产品质量有明显提高。结论改进的制备工艺值得推广     

Understanding reflection behavior as a key for interpreting complex signals in FBRM monitoring of microparticle preparation processes

This study aimed at combining the hen's egg test-chorioallantoic membrane (HET-CAM), bovine corneal opacity and permeability (BCOP) test and histological examination of excised corneas to evaluate the conjunctival and corneal toxicity of niosomes and their ingredients. Various surfactant/lipid combinations and concentrations (1-10%, w/v) were investigated for the ocular delivery of an ambitious drug (naltrexone hydrochloride) for treatment of diabetic keratopathy. Four niosomal formulations were investigated and found to be non irritant to the 10 days old HET-CAMs (an acceptable conjunctival model). Only one of the tested ingredients (sodium cholate - CH) showed moderate irritation, however such an effect was diminished when incorporated into niosomes. Corneal opacity and fluorescein permeability scores for the test substances correlated well with the HET-CAM test results. Corneal erosion and stromal thickness were found to be in agreement with the HET-CAM and BCOP results, which discriminated well between moderately and mildly irritant test substances. Corneal histological examination revealed toxicity signs included epithelial erosion, stromal condensation and stromal vacuolisation, which allowed better discrimination between strong and moderate irritants. It is concluded that the prepared niosomes possess good ocular tolerability and minimal ocular tissue irritation. They can be further investigated as ocular delivery systems using appropriate animal models.     

Critical properties of lactide-co-glycolide polymers for the use in microparticle preparation by the aerosol solvent extraction system.

The Aerosol Solvent Extraction System (ASES) process uses supercritical carbon dioxide for the production of microparticles. Since the critical temperature for this gas is at 304 K, polymers that are used in this process must fulfil certain requirements in crystallinity, and thermal behavior. This can be achieved by the use of blocked copolymers and thus the presence of semicrystalline microdomains in the polymers. However, changing the sequences of the comonomers dilactide and lactide often leads to polymers of low solubility due to long glycolide blocks. In this study, the critical properties of two blocked co-polymers were investigated, such as the blocked structure itself by (1)H-NMR and (13)C-NMR, the thermal behavior by differential scanning calorimetry (DSC), and the crystallinity by powder diffraction. The impact of these properties on microparticles formed by those polymers was also object of these studies. Additionally, two different model drugs, albumin and estriolm were embedded to investigate the impact of different polymer properties on drug content and release.     

Pharmacological modulation of microparticle release: new strategies for the management of atherothrombotic vascular disorders

Microparticles (MPs) are submicron vesicles (0.1-1 μm) shed from the membrane of platelets, monocytes, endothelial cells and other cell types. Abundant clinical evidence relates increased plasma levels of MPs with several cardiovascular and inflammatory diseases, being a topic of tremendous interest in recent years. MPs have been proposed as potential effectors in thrombosis, inflammation, vascular injury or angiogenesis. Although MPs were traditionally considered noxious actors, recent scientific advances revealed another layer of complexity with their diverse roles in the pathophysiology of thrombotic disorders. Therefore, whilst their impact on the evolution of the disease is indisputable, the milieu of factors regulating MP release is still an intriguing field. Since MPs have been shown to be involved in thrombosis and inflammatory diseases, modulation of their release might have important therapeutic applications and provide further insights into their (patho)physiological roles. In this regard, increasing clinical attention has been devoted to the effects of pharmacological agents on MP circulating levels and antigenic composition. This trend led to many recent studies with special focus on the pharmaceutical options to inhibit formation of procoagulant MPs. Thus, this review aims to summarize available clinical and in vitro literature on mechanisms triggering MP release and modulating their activity.     

Progress involving new techniques for liposome preparation

The article presents a review of new techniques being used for the preparation of liposomes. A total of 28 publications were examined. In addition to the theories, characteristics and problems associated with traditional methods, the advantages and drawbacks of the latest techniques were reviewed. In the light of developments in many relevant areas, a variety of new techniques are being used for liposome preparation and each of these new technique has particular advantages over conventional preparation methods. However, there are still some problems associated with these new techniques that could hinder their applications and further improvements are needed. Generally speaking, due to the introduction of these latest techniques, liposome preparation is now an improved procedure. These applications promote not only advances in liposome research but also the methods for their production on an industrial scale.     

Evaluation of the potential of air jet milling of solid protein-poly(acrylate) complexes for microparticle preparation.

It was the aim of this study to evaluate the potential of air jet milling for the preparation of protein-loaded microparticles in industrial quantities. The model protein horseradish peroxidase was incorporated via co-precipitation in carbomer (NaC934P) (1:100) and a poly(methacrylate) (Eudragit L100-55) (1:100) used as carrier matrix. Co-precipitation of the model protein and each polymer in aqueous solution was achieved either by a pH-shift or by the addition of various non-solvents. Dried protein/polymer complexes (desiccator under vacuumization at 4 degrees C with silica blue gel) were ground with an air jet mill and resulting microparticles were investigated regarding protein load, remaining protein activity, size distribution and shape. Results of this study showed that the polymer used and the method of co-precipitation has a great impact on protein load. Using carbomer a maximum protein load of 60 +/- 1% was achieved, whereas in case of Eudragit L100-55 the maximum was 78 +/- 5% (means +/- SD; n = 3-4). Using petroleum ether, isopropanol or tetrahydrofurane as non-solvents led to significantly higher protein loads than a pH-shift from 7 to 5, 4 and 3.5, respectively. Determination of the remaining protein activity after milling showed, that the grinding air pressure (GAP) has a major impact on protein stability. In case of Eudragit L100-55 at a GAP of 4.5 bar peroxidase activity was almost completely lost, whereas 42 +/- 1% loss in activity was determined at a GAP of 2.5 bar. The mean particle size of protein/carbomer and protein/poly(methacrylate) particles was determined to be 3.6-5.2 and 4.5-8.7 microm at a GAP of 2.5 bar and 2.7-3.1 and 2.4-3.1 microm at a GAP of 4.5 bar, respectively. Generally, 90% of all particles were in the range of 3-16 microm. All particles were of spherical shape exhibiting a non-porous surface. According to these results, air jet milling seems to represent a novel method for the large-scale production of protein drug loaded microparticles.     

一种新的制备兽药地昔尼尔的方法

目的 采用新的合成路线制备兽药地昔尼尔(dicyclanil).方法 以N-氰亚胺基-S,S-二硫代碳酸二甲酯、丙二腈、盐酸、环丙胺等为基础原料,经过缩合、环合、取代、氧化、氨化等反应步骤得到高品质的地昔尼尔.结果 通过设计的新的合成路线成功得到高品质的地昔尼尔产品,HPLC分析其含量≥99.9％.结论 该合成工艺,工艺操作简单,设备要求低,生产收率高,适于工业生产.     

Bonnecor--a new anti-arrhythmia preparation

The antiarrhythmic properties of a new drug bonnecor being a derivative of dibenzazepine were studied on different models of arrhythmias. Bonnecor proved to be effective in the treatment of both atrial and ventricular arrhythmias of various genesis except rhythm disorders induced by ouabain intoxication. The drug was shown to exert a pronounced antifibrillatory effect and to increase the electrical stability of the intact and ischemic myocardium.     

Long acting porous microparticle for pulmonary protein delivery

This study investigated the porous-microparticle (PM) with low mass density and large size for pulmonary drug delivery. PM was prepared by the water-in-oil-in-water (W(1)/O/W(2)) multi-emulsion method with cyclodextrin derivative as a porogen and a stabilizer of peptide drugs. Herein, sucrose ethyl acetate (SAIB) was incorporated in PM for long acting protein release. In vitro release studies, the rapid release rate of proteins from PM was reduced due to the high viscosity of the added SAIB. As a result, BSA release from PM continued up to 7 days. This result suggests that PM having sustained release characteristics may be successfully applied for long-term pulmonary administration of protein or peptide drug. In addition, it is expected that these particles arrive at a deep lung epithelium due to low density (high porosity) and limit macrophage recognition because of big particle size (more than 5 microm).     

正交实验法优选感冒清热颗粒的制备工艺

目的研究感冒清热颗粒的制备工艺。方法采取水蒸气蒸馏法提取挥发油,正交实验设计确定挥发油β-环糊精(β-CD)包合的最佳工艺,以葛根素转移率为指标,优选提取工艺。结果挥发油提取条件为:加10倍量水提取6h;环糊精最佳包合工艺为:油与β-CD比例为1∶6,恒温40℃搅拌包合1h;煎煮最佳工艺为:加8倍水,煎煮2次,每次1.5h。结论感冒清热颗粒的制备工艺稳定、可行。