丙烯酸-Pluronic(R) F127接枝共聚物的流变学性质

目的研究丙烯酸Pluronic F127接枝共聚物的流变学性质。方法用同轴圆筒流变仪测定共聚物溶液的流变参数。结果共聚物溶液在较低浓度下具有温度敏感的原位凝胶特性。结论丙烯酸-Pluronic F127接枝共聚物作为一种具有温度敏感原位凝胶性质的材料，具有广泛的应用前景。     

沙棘油静脉乳联合环磷酰胺抗肿瘤实验研究

目的:探讨沙棘油静脉乳对化疗药物环磷酰胺(cyclophosphamide,CTX)抗S180小鼠的增效减毒作用。方法:将接种S180瘤细胞的小鼠分为荷瘤对照组、CTX组、沙棘油静脉乳组(20,10,5mL.kg-1)、沙棘油静脉乳(20,10,5mL.kg-1)+CTX组。给药10d,进行抑瘤率计算,以及外周血常规、骨髓有核细胞计数、脾脏、胸腺质量、网状内皮系统对血流中惰性碳粒的吞噬廓清能力等的检测。结果:沙棘油静脉乳联合CTX各剂量组,肿瘤生长明显低于荷瘤对照组(P<0.01或P<0.05),沙棘油静脉乳+CTX组肿瘤生长低于CTX组(P<0.05)。与荷瘤对照组相比,CTX组骨髓有核细胞数、WBC、胸腺指数、脾指数明显下降。与CTX组相比,沙棘油静脉乳中、高剂量组联合CTX组可使骨髓有核细胞数、外周血白细胞数、脾指数明显升高(P<0.01或P<0.05);沙棘油静脉乳20mL.kg-1的吞噬系数明显高于正常对照组(P<0.05),显著提高正常小鼠的碳粒廓清能力。结论:沙棘油静脉乳对化疗药物CTX抗S180小鼠具有增效减毒的作用。沙棘油静脉乳能明显提高非特异性免疫功能。     

丙烯酸-Pluronic~ F127接枝共聚物的流变学性质

目的研究丙烯酸Pluronic F127接枝共聚物的流变学性质。方法用同轴圆筒流变仪测定共聚物溶液的流变参数。结果共聚物溶液在较低浓度下具有温度敏感的原位凝胶特性。结论丙烯酸-Pluronic F127接枝共聚物作为一种具有温度敏感原位凝胶性质的材料,具有广泛的应用前景。     

Functionalized and graft copolymers of chitosan and its pharmaceutical applications

Introduction: Chitosan is the second most abundant natural polysaccharide. It belongs a family of polycationic polymers comprised of repetitive units of glucosamine and N-acetylglucosamine. Its biodegradability, nontoxicity, non-immunogenicity and biocompatibility along with properties like mucoadhesion, fungistatic and bacteriogenic have made chitosan an appreciated polymer with numerous applications in the pharmaceutical, comestics and food industry. However, the limited solubility of chitosan at alkaline and neutral pH limits its widespread commercial use. This can be circumvented by fabrication of chitosan by graft copolymerization with acyl, alkyl, monomeric and polymeric moieties.

Areas covered: Modifications like quarterization, thiolation, acylation and grafting result in copolymers with higher mucoadhesion strength, increased hydrophobic interactions (advantageous in hydrophobic drug entrapment), and increased solubility in alkaline pH, the ability for adsorption of metal ions, protein and peptide delivery and nutrient delivery. Insights on methods of polymerization, including atomic transfer radical polymerization and click chemistry are discussed. Applications of such modified chitosan copolymers in medical and surgical, and drug delivery, including nasal, oral and buccal delivery have also been covered.

Expert opinion: Despite a number of successful investigations, commercialization of chitosan copolymers still remains a challenge. Further advancements in polymerization techniques may address the unmet needs of the healthcare industry.     

Design of nanoparticles composed of graft copolymers for oral peptide delivery

The development of a dosage form that improves the absorption of peptide and protein drugs via the gastrointestinal tract is one of the greatest challenges in the pharmaceutical field. Many researchers have taken up the challenge, using approaches including mucoadhesive drug delivery, colon delivery, particulate drug delivery such as nanoparticles, microcapsules, liposomes, emulsions, micelles, and so on. The objective of this article is to provide the reader with outlines of novel nanoparticle technologies for oral peptide delivery based on polymer chemistry. The physicochemical properties of nanoparticles and their behavior on exposure to physiological media are greatly dominated by their chemical structures and surface characteristics. We will especially focus on the design of nanoparticles composed of novel graft copolymers having a hydrophobic backbone and hydrophilic branches as drug carriers.     

氯分析仪测定氯化钠含量的方法验证

目的 验证CL925型氯分析仪测定氯化钠含量的方法.方法 进行线性试验、精密度试验、准确性试验及专属性试验比较仪器法和法定方法测定氯化钠含量的结果.结果 线性关系良好,决定系数为0.9999,精密度好,平均回收率为100.4％.两种方法测得的氯化钠含量结果的差异无统计学意义(t =0.515,P=0.5).结论 CL9...     

丙烯酸-Pluronic(R) F127接枝共聚物的流变学性质

目的 研究丙烯酸Plurinic(R) F127接枝共聚物的流变学性质.方法 用同轴圆筒流变仪测定共聚物溶液的流变参数.结果 共聚物溶液在较低浓度下具有温度敏感的原位凝胶特性.结论 丙烯酸-Pluronic(R) F127接枝共聚物作为一种具有温度敏感原位凝胶性质的材料,具有广泛的应用前景.     

应用动物活体生物发光技术观察紫杉醇混合胶束的抑瘤效果

活体动物成像技术是近年来发展成熟并得到认可的一种新型影像检测技术,其突出优越性是可以对活体病灶的形态大小进行在体无损伤直观准确检测[1]。活体动物成像技术的基本原理是透过体表,接     

吲哚美辛乳剂对皮肤刺激性和过敏性研究

目的考察吲哚美辛乳剂的皮肤刺激性和皮肤过敏性,为临床安全用药提供依据。方法采用新西兰白兔进行皮肤刺激性实验,分为完整皮肤组和破损皮肤组,每组8只。采用同体左、右侧自身对比法,左侧给予吲哚美辛乳剂0.5g,右侧给予等量空白乳剂,连续给药14d。实验期间观察皮肤刺激反应,每组6只于末次给药后72h处死,取皮肤做组织病理检查,剩余2只于末次给药后14d取皮肤做病理检查。采用豚鼠进行皮肤过敏实验,于第0、7、14天给予吲哚美辛0.5g局部诱导,第28天在未给药豚鼠的肋腹部皮肤给予吲哚美辛0.4g以局部激发。结果吲哚美辛乳剂对兔正常皮肤和破损皮肤均有轻微刺激性,但停药后可恢复,对豚鼠皮肤无过敏反应。结论吲哚美辛乳剂在临床上不宜长期使用,需重点观察皮肤刺激性。     

Self-assembled amphiphilic hyaluronic acid graft copolymers for targeted release of antitumoral drug

Polymeric micelles obtained by self-assembling of amphiphilic hyaluronic acid (HA) graft copolymers have been prepared and characterized. In particular, hyaluronic acid (HA) has been grafted to polylactic acid (PLA) and polyethylenglycol chains (PEG), then the copolymers able to form micelles in aqueous medium have been chosen to entrap the antitumoral drug Doxorubicin. The critical aggregation concentration of HA-g-PLA or HA-g-PLA-g-PEG micelles has been determined by using pyrene as a fluorescent probe, whereas their shape and size have been evaluated by light scattering measurements, scanning and transmission electron microscopies. The selective cytotoxicity of drug loaded micelles toward the CD-44 over-expressing HCT-116 cells compared to receptor deficient human derm fibroblasts has been demonstrated. Pegylated micelles showed better stability and drug loading capacity and they were able to escape from macrophage phagocytosis.     

Shape-controlled fabrication of zein and peach gum polysaccharide based complex nanoparticles by anti-solvent precipitation for curcumin-loaded Pickering emulsion stabilization

Owing to the high desorption energy of colloidal particles, Pickering emulsions can effectively protect the encapsulated bioactives. In this study, zein and peach gum polysaccharide (PGP) based biopolymeric nanoparticles were fabricated to stabilize the Pickering emulsion and deliver curcumin. Effects of the PGP addition order during and after anti-solvent precipitation process (zein-PGP nanoparticles or zein/PGP nanoparticles) on the properties of nanoparticles were discussed. The zein-PGP nanoparticles were spherical with mean size of 172.8 nm, while zein/PGP nanoparticles were rod-like with mean size of 207.5 nm. Both zein-PGP and zein/PGP nanoparticles were negatively charged with the wettability of 93.5° and 90.3°, respectively. Compared to the zein NPs, the zein-PGP and zein/PGP nanoparticles stabilized emulsions had smaller droplet size, better storage and environmental stabilities. The release rates of curcumin in zein-PGP nanoparticles and zein/PGP nanoparticles stabilized emulsions were 23.4% and 26.7% respectively in simulated gastric fluid. The curcumin release rates in zein-PGP nanoparticles and zein/PGP nanoparticles stabilized emulsions were 32.5% and 24.0% respectively in simulated intestinal fluid. These findings might promote an effective delivery system for bioactive food ingredients using zein and PGP based complex nanoparticles.     

Solubilization and stabilization of an investigational antineoplastic drug (NSC no. 278214) in an intravenous formulation using an emulsion vehicle

The use of parenteral fat emulsions for development of an extemporaneous preparation of an intravenous formulation of a poorly water-soluble and unstable investigational anticancer agent (NSC no. 278214) is presented. The incorporation into a commercial fat emulsion of the drug, dissolved in dimethylacetamide-cremophor solution, results in a suitable parenteral formulation in which the drug is approximately 100-fold more stable than in simple aqueous solutions.     

离子交换色谱法测定去甲基斑蝥素乳剂的含量

目的:建立离子交换色谱法测定去甲基斑蝥素乳剂含量的方法.方法:采用Hypersil SAX色谱柱(250mm×4.6 mm,5 μm),以0.3%磷酸-甲醇(75:25)为流动相,流速0.6 mL·min-1;检测波长:210 nm;柱温:室温.结果:在本色谱条件下测定去甲基斑蝥素线性范围为2～80 μg·mL-1,相关系数r=0.999 9;高、中、低3个浓度的平均日内精密度RSD值分别为0.41%,0.46%和0.57%,日间精密度RSD分别为4.2%,6.2%和4.5%(n=5),样品测定方法回收率平均为98.9%,最低检测浓度为0.05 μg·mL-1.结论:本方法简便快捷、灵敏度高、重现性好.     

Determination of optical purity by nonenantioselective LC using CD detection

The use of a circular dichroism (CD) based HPLC detection system was recently described by some authors and proposed for a nonenantioselective HPLC enantiomeric purity determination. Indeed the system, measuring both CD and UV signals simultaneously, allows the evaluation of the g anisotropy factor. In order to experimentally support such an analytical procedure as an alternative to the enantioselective chromatographic method currently found in some pharmacopoeial monographs, we have studied its application to the analysis of dexchlorpheniramine maleate, an active substance which exhibits a poor CD signal in the 250–270 nm spectral region with a g value of the order of 10⁻⁴. The results reported indicate that the suitability of the studied procedure for the enantiomeric purity determination is obtained only when the CD-detector reaches high stability; indeed a certain time lag is systematically necessary to obtain stable responses, i.e. adequate precision. The enantioselective HPLC procedure seems to be more precise for enantiomeric purity values ≤2% than the CD based detection system; such a disadvantage might be counterbalanced by the use of non chiral stationary phases.     

Sustained release of bovine serum albumin using implantable wafers prepared by MPEG-PLGA diblock copolymers

MPEG-PLGA diblock copolymers, consisting of methoxy polyethylene glycol (MPEG) and poly(L-lactic-co-glycolic acid) (PLGA), were synthesized by ring-opening polymerization of L-lactide and glycolide in the presence of MPEG as an initiator. Implantable wafers, using diblock copolymers as a drug carrier, were fabricated by direct compression method after freeze milling of the diblock copolymers and bovine serum albumin-fluorescein isothiocyanate (BSA-FITC) as a model protein drug. The wafers prepared with MPEG-PLGA diblock copolymers exhibited initial burst in the release of BSA. The BSA release profiles from the wafers depended on MPEG-PLGA diblock copolymer compositions. The in vitro release of the BSA also correlated with the degradation rate of the PLGA part in the diblock polymers. The wafers prepared from diblock copolymers with an increased MPEG segment showed the more structural metamorphosis of crack form due to higher water absorption of MPEG inside the wafer, and induced faster BSA release. The wafers prepared by using MPEG-PLGA diblock copolymers in the presence of small intestinal submucosa (SIS) as a drug carrier additive exhibited controlled BSA release profiles, although the wafers exhibited release patterns with a lag time at the initial stage as the MPEG segment in diblock copolymer compositions increased. Thus, we confirmed that the MPEG-PLGA diblock copolymers could be used as a protein delivery carrier in implantable wafer form.     

Drug release from a new family of graft copolymers of methyl methacrylate. I.

Hydrophilic matrices are an interesting option when developing an oral drug release device. In this work we have produced hydrophilic matrices tablets by direct compression. Previously graft copolymers were synthesized as an important component of the tablets: hydroxypropyl starch-methyl methacrylate (HS-MMA), carboxymethyl starch-MMA (CS-MMA) and hydroxypropyl cellulose-MMA (HC-MMA). The polymeric component was mixed with Emcompress®, stearic acid and theophylline. All the products fulfilled the requirements for good flow according to literature. L-formulations show lower values of plasticity than O-formulations. However, L-formulations exhibit higher compactibility values than O-formulations. In general, all the formulations with O-polymers show faster release of the drug at three pHs used. On the other hand, these tablets have the capacity to hydrate quickly forming a gelatinous layer, so it is necessary to achieve controlled drug release from hydrophilic matrices. In relation with the dissolution efficiency over 8 h, formulations with HS-MMAL and NaCMC show very similar results, although the release of theophylline from NaCMC tablets at different pHs was always slightly slower than HS-MMAL tablets.     

The control of oil-in-water emulsion consistency using mixed emulsifiers

Mixtures of emulsifiers of the surfactant-fatty alcohol type are widely used to stabilize oil-in-water emulsions and to alter their consistency from fluid to semi-solid. A mechanism, involving the formation of a viscoelastic network in the continuous phase, is proposed to explain this self-bodying action. Evidence has been adduced from published data on a variety of systems. Support for this concept is also provided by the results obtained from a concentric cylinder study of the rheology of liquid paraffin in water emulsions containing a fixed concentration of cetostearyl alcohol and varying amounts of polyoxyethylene sorbitan monooleate, cetomacrogol 1000, sodium dodecyl sulphate or cetrimide.