壳聚糖-阿拉伯胶布洛芬缓释微囊制备工艺研究

本文以壳聚糖和阿拉伯胶为囊材,利用复凝聚法将布洛芬微囊化。以微囊的药物包封率为制备工艺优化指标,通过正交实验得出微囊的最佳制备工艺条件为：壳聚糖浓度为0．2％、成囊pH为4．5、成囊温度为45℃、搅拌速度为200rpm。以最佳制备工艺条件制备含药微囊,重现性好,工艺稳定,同时体外溶出实验表明,该微囊具有较好的缓释作用。     

免疫球蛋白缓释微囊的制备、结构表征与性能研究

微囊化是实现生物药物制剂缓控释放的最重要方法之一。以乙基纤维素(EC)为囊材,采用物理化学方法制备了免疫球蛋白乙基纤维素微囊。用扫描电镜(SEM)考察了微囊的孔结构和形貌特征,并通过体外溶出实验考察了微囊的缓释效果。结果表明,在给定制备条件下制得的微囊圆整度好,孔径分布范围较窄,在模拟条件下具有良好的缓释性能。微囊最佳制备工艺条件如下:囊心囊材比2.5∶1,30℃下反应6h,搅拌速率250r/min,吐温80用量8ml。     

壳聚糖-海藻酸钠靛玉红自微乳缓释微囊制备、评价及体外释放的研究

以靛玉红自微乳为囊心物,壳聚糖和海藻酸钠为囊材,采用复凝聚法制备壳聚糖-海藻酸钠靛玉红自乳化缓释微囊,通过正交实验和单因素考察确定壳聚糖-海藻酸钠靛玉红缓释微囊的最佳制备工艺。并以载药量、包封率为评价指标对其进行质量评价,同时以体外释放度评价其释药性能。壳聚糖-海藻酸钠靛玉红缓释微囊的最佳工艺是海藻酸钠的浓度为1.5%,靛玉红自微乳体积、海藻酸钠体积、壳聚糖质量三者比例为1∶1∶0.5,氯化钙浓度的最佳浓度为2.0%。采用该工艺制备的微囊载药量为0.0416%、包封率为79.2%,体外释放24 h累积释放率为(97.1±2.68)%。该微囊的释放符合Higuchi方程和一级释药模型,具有较好的缓释作用。     

茶多酚微胶囊化工艺及其缓释研究

本文利用单因素与正交实验,对影响茶多酚微胶囊化包埋效果的因素进行了分析,确定了茶多酚微胶囊化的最佳工艺条件。结果表明:茶多酚微囊化包埋的最佳工艺条件为:采用3%的海藻酸钠(海藻酸钠:茶多酚=3:1),1%的壳聚糖和4%的氯化钙体系,用一步法可制备茶多酚微胶囊,该微胶囊在体外模拟胃、肠液中约2 h中达到茶多酚释放峰值,表现出较好的缓释效果。     

萘普生缓释微球制备工艺及性能研究

本文利用壳聚糖和海藻酸钠通过复凝聚法将萘普生制成微球,研究成球的最佳制备工艺条件及载药微球性能,制备了可生物相容,自然降解无毒的载药微球。实验中,以微球的药物包封率为制备工艺优化指标,通过正交实验得出微球的最佳制备工艺条件为:壳聚糖浓度∶海藻酸钠浓度为1:1,pH值为4.0,搅拌速度为300rpm,反应温度为35℃。以最佳制备工艺条件制备的含药微球,重现性好,工艺稳定,同时体外溶出实验表明,该微球具有较好的缓释作用。     

葡萄糖基聚合物的酶催化合成及其在制备缓释微球中的应用

以脂肪酶Novozym-435催化葡萄糖和10-十一碳烯酸合成了6-O-(10-十一碳烯酸)-葡萄糖酯,在K2S2O8引发下合成了葡萄糖基聚合物.采用复凝聚法以葡萄糖基聚合物和海藻酸钠为基质材料,将非诺洛芬钙包裹制成缓释微球.通过L9(34)正交实验得出微球的最佳制备工艺条件,结果是葡萄糖基聚合物:海藻酸钠质量比=1:2,pH 3.0,搅拌速度400 r/min,反应成球温度45℃.在最佳工艺条件下制备的非诺洛芬钙缓释微球,粒径范围是10～20μm,平均药物包封率(73.74±3.12)%.同时,体外溶出试验表明,该微球具有较好的缓释作用.     

壳聚糖的特性对吲哚美辛微囊性能的影响

本研究利用自制的壳聚糖与阿拉伯胶为壁材,以戊二醛为固化交联剂,通过复凝法制备吲哚美辛载药微囊;研究了不同分子量、不同脱乙酰度的壁材壳聚糖对所形成微囊的性能的影响.结果表明:不同脱乙酰度与不同分子量的壳聚糖所制的载药微囊包封率、载药量、粒径、吸水溶胀性能等都有一定差别,体外溶出实验表明他们缓释与控释性能也有不同.     

薰衣草精油缓释固体分散体的制备及其体外释药性能研究

目的：优化薰衣草精油（LEO）缓释固体分散体的制备工艺,并探讨体外释药模型。方法：以芳樟醇及乙酸芳樟酯为指标,建立气相-色谱质谱联用（GC-MS）技术测定溶出度的方法;选用硬脂酸、聚乙二醇6000(PEG 6000)和单硬脂酸甘油酯为辅料,优化辅料配比,采用熔融法制备LEO缓释固体分散体,考察其体外释药性能。结果：LEO缓释固体分散体的最佳处方配比为硬脂酸∶PEG 6000∶单硬脂酸甘油酯：LEO=3∶5∶1∶1,该条件下所制备的固体分散体在体外能够持续释药12 h,体外释药符合一级动力学模型。结论：所优选的处方配比工艺稳定可靠,所得缓释固体分散体能显著改善药物溶出,缓释效果令人满意。     

阿莫西林微囊的制备及临床应用研究

目的:研究阿莫西林微囊的制备及临床应用。方法选取乙基纤维素作为包囊材料,使用液中干燥法对阿莫西林微囊进行制备,进而对微囊的含量、粒度分布以及临床应用进行研究。结果:利用液中干燥法制备阿莫西林微囊,其粒度分布在150um到850um之间,收率高达85%以上。结论:通过临床应用研究,阿莫西林微囊的缓释作用比阿莫西林粉末更为显著。     

白芨口腔溃疡贴膜的研究

本文研究了白芨口腔溃疡贴膜的制备工艺,并进行了性能测试和人体试验。结果表明,最佳工艺条件:胶液粘度为1 060 mPa.s;膜厚为0.20~0.25 mm;甘油添加量3.0%,60℃下热风干燥3 h。该贴膜有较强的粘贴力、缓释性和局部滞留性;工艺简单、成本低;使用方便、收效甚佳。     

Development of hydrocortisone succinic acid/and 5-fluorouracil/chitosan microcapsules for oral and topical drug deliveries

Recently, we demonstrated the safety use of calendula oil/chitosan microcapsules as a carrier for both oral and topical deliveries. We also reported the improved biological activity towards skin cells and Staphylococcus aureus of phyllanthin containing chitosan microcapsules. However, the possibility of both oral and topical applications was still necessary to be further studied. Here we investigated that both oral and topical applications of chitosan-based microcapsules were tested using hydrocortisone succinic acid (HSA) and 5-fluorouracil (5-FU), respectively. The drug loading efficiency, particle size, surface morphology and chemical compositions of both drug loaded microcapsules were confirmed by UV-vis spectrophotometer, particle size analyzer, scanning electron microscope and Fourier transform infrared spectroscopy. The in vitro release studies revealed that both HSA and 5-FU could be released form chitosan microcapsules. The mean adrenocorticotropic hormone concentration in HSA loaded microcapsule mice plasma was detected to be lower than that of water control. One hundred micrograms per milliliter of 5-FU containing microcapsules exhibited a stronger growth inhibition towards skin keratinocytes than that of free 5-FU. In vitro drug delivery model demonstrated the delivery of 5-FU from microcapsule treated textiles into nude mice skin. Further uses of the drug loaded microcapsules may provide an efficiency deliverable tool for both oral and topical applications.     

Development of In Situ Gelling and Bio Adhesive 5-Fluorouracil Enema

In this study, a novel 5-Fluorouracil (5-FU) enema with good bio adhesion and temperature sensitivity was developed using in situ gelling technology. The preparation was formulated as a free-flowing liquid before use, while a layer of gel film was quickly formed when administered in the rectum, with a large contact surface area. It also demonstrated good biocompatibility, appropriate gel strength and bio adhesive force with excellent adhesion to rectal mucosa and prolonged action time, allowing more effective drug absorption and diffusion to surrounding tissues. Poloxamer 407 and poloxamer 188 were applied to adjust the gelling temperature. With the addition of carbopol and polycarbophil (bio adhesive substances), the solubility of 5-FU and gel strength increased, the temperature of gelation and the surface area of drug contact on mucous epithelium decreased. Decreased adhesive force between the preparation and the mucous membrane of the rectum was demonstrated with improving carbopol and polycarbophil’s concentration. In vitro release demonstrated that 5-FU in situ gelling enema with different bases had a rapid and almost complete drug release. We used an optimized formulation of P407/P188/polycarbophil/5-FU (17/2.5/0.2/1.0) for animal experiments. The result showed that the drug evenly covered the surface of the rectum and there was no leakage in 6 hours. The in situ gelling enema showed significantly higher rectal tissue levels of 5-FU compared with suppository and intravenous administration, indicating that 5-FU could be well absorbed due to the enlarged releasing area, longer retention time and larger amount of dissolved active ingredients. Systemically, 5-FU levels in the enema group were similar to those in the suppository group and significantly lower than the intravenous group. The enema was not associated with morphological damage to rectal tissue. These results suggest that the bio adhesive and in situ gelling enema could be a more effective rectal delivery system of 5-FU.     

Short oligonucleotide prodrug having 5-fluoro and 5-iodouracil inhibits the proliferation of cancer cells in a photo-responsive manner

Photo-induced C1′ hydrogen abstraction of 5-fluoro-2′-deoxyuridine was adopted as the key reaction for releasing 5-fluorouracil (5-FU) anticancer drug from oligonucleotide strands. After photoirradiation following 5-FU release, anticancer activity was expected. We demonstrated that oligonucleotide tetramer, d(A^FU^IUA), can release 5-FU under physiological conditions in a photo-responsive manner thorough photo-induced C1′ hydrogen abstraction, and that the 5-FU released from d(A^FU^IUA) having a phosphorothioate backbone clearly suppresses the proliferation of HeLa cells in a photo-responsive manner.     

Simple and sensitive determination of 5-fluorouracil in plasma by high-performance liquid chromatography: Application to clinical pharmacokinetic studies

5-Fluorouracil (5-FU) is an antineoplastic agent widely employed in the treatment of many types of cancer. Recent studies have proved the need for individual adjustment of 5-FU dosage based on pharmacokinetics. A simple and sensitive high-performance liquid chromatographic method for the determination of 5-FU in plasma and their preliminary clinical pharmacokinetics is described. After sample acidification with 20 μl of orthophosphoric acid (5%), the drug is extracted from plasma using n-propanol–diethyl ether (16:84). The organic layer is evaporated to dryness, the residue dissolved in 100 μl of mobile phase and 20 μl of this mixture is injected into a LiChrospher 100RP-18 (5 μm, 250×4.0 mm) analytical column. Mobile phase consisted of potassium dihydrogenphosphate (0.05 M, adjusted to pH 3). The limit of quantitation was 2 ng/ml. The method showed good precision: the within-day relative standard deviation (RSD) for 5-FU (10–20 000 ng/ml) was 3.75% (2.57–5.93); the between-day RSD for 5-FU, in the previously described range, was 5.74% (4.35–7.20). The method presented here is accurate, precise and sensitive and it has been successfully applied for 5-FU pharmacokinetic investigation and therapeutic drug monitoring.     

Targeted Anticancer Drug Delivery Using Chitosan,Carbon Quantum Dots,and Aptamers to Deliver Ganoderic Acid and 5-Fluorouracil

Breast cancer is a malignancy that affects mostly females and is among the most lethal types of cancer. The ligand-functionalized nanoparticles used in the nano-drug delivery system offer enormous potential for cancer treatments. This work devised a promising approach to increase drug loading efficacy and produce sustained release of 5-fluorouracil (5-FU) and Ganoderic acid (GA) as model drugs for breast cancer. Chitosan, aptamer, and carbon quantum dot (CS/Apt/COQ) hydrogels were initially synthesized as a pH-sensitive and biocompatible delivery system. Then, CS/Apt/COQ NPs loaded with 5-FU-GA were made using the W/O/W emulsification method. FT-IR, XRD, DLS, zeta potentiometer, and SEM were used to analyze NP's chemical structure, particle size, and shape. Cell viability was measured using MTT assays in vitro using the MCF-7 cell lines. Real-time PCR measured cell apoptotic gene expression. XRD and FT-IR investigations validated nanocarrier production and revealed their crystalline structure and molecular interactions. DLS showed that nanocarriers include NPs with an average size of 250.6 nm and PDI of 0.057. SEM showed their spherical form, and zeta potential studies showed an average surface charge of +37.8 mV. pH 5.4 had a highly effective and prolonged drug release profile, releasing virtually all 5-FU and GA in 48 h. Entrapment efficiency percentages for 5-FU and GA were 84.7±5.2 and 80.2 %±2.3, respectively. The 5-FU-GA-CS-CQD-Apt group induced the highest cell death, with just 57.9 % of the MCF-7 cells surviving following treatment. 5-FU and GA in CS-CQD-Apt enhanced apoptotic induction by flow cytometry. 5-FU-GA-CS-CQD-Apt also elevated Caspase 9 and downregulated Bcl2. Accordingly, the produced NPs may serve as pH-sensitive nano vehicles for the controlled release of 5-FU and GA in treating breast cancer.     

Formulation and characterization of nanoliposomal 5-fluorouracil for cancer nanotherapy

A scalable and safe method was developed to prepare nanoliposome carriers for the entrapment and delivery of 5-fluorouracil (5-FU). The carrier systems were composed of endogenously occurring dipalmitoylphosphatidylcholine (DPPC), negatively charged dicetylphosphate (DCP), cholesterol (CHOL) and glycerol (3%, v/v). Nanoliposomes were prepared by the heating method in which no harmful chemical or procedure is involved. Results indicated fast and reproducible formation of non-toxic liposomes that possess high entrapment efficiency (up to 96.9%) and vesicle size range of ca. 530–620?nm. Transmission electron and optical micrographs of the 5-FU liposomes revealed that they were spherical and some were multilayered. There was an increase in the release rate of 5-FU from the liposomes prepared with a high ratio of drug:lipid. The release data showed that the highest release rates were obtained for nanoliposomes containing 5-FU with the drug concentration of 500?mM and that it followed the diffusion model. Nanoliposome preparation method introduced here has the potential of large-scale manufacture of safe and efficient carriers of 5-FU.     

Combinations of 5-fluorouracil with UCN-01 or staurosporine

The action of 5-Fluorouracil (5-FU) is mediated by inhibition of thymidylate synthase (TS), which is regulated by cell cycle proteins controlled by protein phosphorylation. We studied the effects of staurosporine and its analogue UCN-01, inhibitors of protein kinase C (PKC) on 5-FU cytotoxicity in Lovo colon cancer cells. Each drug contributes equally to the cell cycle effects of the 5-FU combinations. In sequential drug administration, the cell cycle distribution was determined by the first drug. Simultaneous 5-FU combinations induced additive effects in induction of apoptosis. When staurosporine was used as the second drug, induction of apoptosis was 2-fold higher than the sum of both drugs alone. Based on induction of apoptosis 5-FU addition prior to the PKC inhibitors seemed preferable.     

The chemotherapeutic drug 5-fluorouracil promotes PKR-mediated apoptosis in a p53-independent manner in colon and breast cancer cells

The chemotherapeutic drug 5-FU is widely used in the treatment of a range of cancers, but resistance to the drug remains a major clinical problem. Since defects in the mediators of apoptosis may account for chemo-resistance, the identification of new targets involved in 5-FU-induced apoptosis is of main clinical interest. We have identified the ds-RNA-dependent protein kinase (PKR) as a key molecular target of 5-FU involved in apoptosis induction in human colon and breast cancer cell lines. PKR distribution and activation, apoptosis induction and cytotoxic effects were analyzed during 5-FU and 5-FU/IFNα treatment in several colon and breast cancer cell lines with different p53 status. PKR protein was activated by 5-FU treatment in a p53-independent manner, inducing phosphorylation of the protein synthesis translation initiation factor eIF-2α and cell death by apoptosis. Furthermore, PKR interference promoted a decreased response to 5-FU treatment and those cells were not affected by the synergistic antitumor activity of 5-FU/IFNα combination. These results, taken together, provide evidence that PKR is a key molecular target of 5-FU with potential relevance in the clinical use of this drug.     

5-Fluorouracil Nanoparticles Inhibit Hepatocellular Carcinoma via Activation of the p53 Pathway in the Orthotopic Transplant Mouse Model

Biodegradable polymer nanoparticle drug delivery systems provide targeted drug delivery, improved pharmacokinetic and biodistribution, enhanced drug stability and fewer side effects. These drug delivery systems are widely used for delivering cytotoxic agents. In the present study, we synthesized GC/5-FU nanoparticles by combining galactosylated chitosan (GC) material with 5-FU, and tested its effect on liver cancer in vitro and in vivo. The in vitro anti-cancer effects of this sustained release system were both dose- and time-dependent, and demonstrated higher cytotoxicity against hepatic cancer cells than against other cell types. The distribution of GC/5-FU in vivo revealed the greatest accumulation in hepatic cancer tissues. GC/5-FU significantly inhibited tumor growth in an orthotropic liver cancer mouse model, resulting in a significant reduction in tumor weight and increased survival time in comparison to 5-FU alone. Flow cytometry and TUNEL assays in hepatic cancer cells showed that GC/5-FU was associated with higher rates of G0–G1 arrest and apoptosis than 5-FU. Analysis of apoptosis pathways indicated that GC/5-FU upregulates p53 expression at both protein and mRNA levels. This in turn lowers Bcl-2/Bax expression resulting in mitochondrial release of cytochrome C into the cytosol with subsequent caspase-3 activation. Upregulation of caspase-3 expression decreased poly ADP-ribose polymerase 1 (PARP-1) at mRNA and protein levels, further promoting apoptosis. These findings indicate that sustained release of GC/5-FU nanoparticles are more effective at targeting hepatic cancer cells than 5-FU monotherapy in the mouse orthotropic liver cancer mouse model.     

Gas chromatographic—mass spectrometric method for routine monitoring of 5-fluorouracil in plasma of patients receiving low-level protracted infusions

A gas chromatographic—mass spectrometric (GC—MS) method is described which quantitates 5-fluorouracil (5-FU) plasma levels ranging from 0.5 to 50 ng/ml. The analysis uses two internal standards, 1,3-[¹⁵N₂]-5-fluorouracil and 5-chlorouracil. Extraction and derivatization of the pyrimidine bases were accomplished in a single step using acetonitrile. Compounds were analyzed as their 1,3-dipentafluorobenzyl derivatives by electron-impact MS, and the GC—MS analysis was automated with respect to sample injection and data reduction. Stability of the analysis was demonstrated by continuous unattended analysis of 5-FU in human plasma for periods of up to three days with no deterioration of the quantitative results. The method is applicable to quantitating 5-FU plasma levels in patients receiving protracted infusions of the drug for colorectal cancer or other malignancies.