Design of antihistaminic transdermal films based on alginate–chitosan polyelectrolyte complexes: characterization and permeation studies

The purpose of this study was to develop suitable matrix-type transdermal drug delivery systems of Ketotifen fumarate (KF) as antiasthmatic drugs. Chitosan–alginate polyelectrolyte complex (PEC) films were used as drug release regulators for KF. Antihistaminic films with variable PEC compositions were prepared using different ratios of chitosan (CTS) to sodium alginate (ALG). Propylene glycol (PG) was used as plasticizer; Tween 80 (T₈₀) and Span 20 (S₂₀) were used as permeability enhancers. Nine formulations were obtained by film casting method and characterized in terms of weight uniformity, thickness, folding endurance, moisture lost, and moisture absorption. In addition, drug release and permeation through rat abdominal skin mounted in Franz cell were investigated. All formulations were found to be suitable in terms of physicochemical characteristics, and there was no significant interaction between the used drug and polymers. It was noticed that when T₂₀ is used as permeation enhancer, a satisfactory drug release pattern was found where 99.88% of drug was released and an amount of 2.121?mg/cm² of KF was permeated after 24?h. For the optimal formulation, a permeability coefficient of 14.00?±?0.001?cm h^?1 and a latency time of 0.35?±?0.02?h were found. The in-vitro analysis showed controlled release profile which was fitted by Korsmeyer–Peppas model (R²?=?0.998). The obtained results suggested that new controlled release transdermal formulations of asthmatic drugs could be suitably designed as an alternative to the common forms.     

氧化海藻酸钠交联壳聚糖载药复合体系的制备及其药物缓释初步研究

为获得一种新型的药物释放复合体系,本实验首先通过乳化交联法制备壳聚糖(CS)包载四环素(TC)微球,然后利用氧化海藻酸钠交联聚磷酸钙/壳聚糖(CPP/CS)复合材料,用冷冻干燥法制备了载药微球复合体系.并用傅立叶红外光谱仪(IR)、扫描电镜(SEM)及药物的体外释放等方法对该载药微球复合体系进行分析和表征.结果显示,经...     

自修复氧化海藻酸钠-羧甲基壳聚糖水凝胶的制备及药物缓释性能

本研究基于动态亚胺键合成了一种具有自修复性能的氧化海藻酸钠-羧甲基壳聚糖水凝胶(OSA-CMCS).通过海藻酸钠的糖醛酸,合成了OSA,并通过与CMCS的席夫碱反应制备了具有不同交联度的自修复OSA-CMCS水凝胶,研究了OSA-CMCS水凝胶的微观形态、黏弹性能、溶胀性能、自修复性能、酶促降解性能和体外药物释放性能....     

pH-sensitive sodium alginate/calcined hydrotalcite hybrid beads for controlled release of diclofenac sodium

Objective: The aim of this study was to prepare pH-sensitive sodium alginate/calcined hydrotalcite (SA/CHT) hybrid bead with improved the burst release effect of the drug.

Materials and methods: A series of pH-sensitive SA/CHT hybrid beads were prepared by using Ca²⁺ cross-linking in the presence of diclofenac sodium (DS) and SA. The structure and drug loading of the beads were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. The swelling and the drug release of the fabricated beads were investigated by the pH of test medium and CHT content.

Result: The formed positively charged hydrotalcite layers were adsorbed on the negatively charged SA polymer chains through electrostatic interaction and act as inorganic cross-linkers in the three-dimensional network. Compared to pure SA beads, the incorporation of CHT enhanced the drug encapsulation efficiency, improved the swelling behaviors and slowed the drug release from the hybrid beads.

Discussion and conclusions: The electrostatic interaction between hydrotalcite and SA has restricted the movability of the SA polymer chains, and then slowed down swelling and dissolution rates in aqueous solutions. The results provided a simple method to moderate drug release and matrix degradation of the SA beads.     

海藻酸钠阳离子交换膜的改性及表征

以海藻酸钠(SA)为原料,以羧基化多壁碳纳米管(cMWCNTs)为改性剂,再通过涂敷浸渍的方法与热塑性聚氨酯(TPU)导电无纺布复合得到改性SA阳离子交换膜。利用热失重分析仪(TG)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)、绝缘电阻测试仪和万能材料试验机对SA阳离子膜的结构和性能进行表征。结果表明:与SA阳离子交换膜相比,经cMWCNTs和TPU导电无纺布改性后膜的电阻率显著降低,导电能力提高;改性SA阳离子膜的表面平整、光滑,未出现气泡等缺陷,TPU导电无纺布与SA膜间界面结合力较强;改性后,膜的热稳定性和力学性能得到显著提高。     

氧化海藻酸钠/聚丙烯酰胺水凝胶的制备与表征

通过水-乙醇和水-正丙醇两种不同的溶剂体系制备高分子量和不同氧化度的氧化海藻酸钠(OSA),然后引入聚丙烯酰胺(PAM)交联网络结构,通过二步法获得OSA/PAM复合水凝胶。探讨了不同反应体系下,HCl体积分数对OSA分子量的影响以及氧化剂(高碘酸钠NaIO_4)添加量、反应时间对OSA氧化度的影响规律。结果表明:在水-正丙醇体系下,HCl体积分数为24vol%时,氧化海藻酸钠的分子量达到170 000;调节NaIO_4的添加量和反应时间可以控制OSA的氧化度在10%~85%范围内变化。在此基础上对OSA/PAM复合水凝胶的溶胀率和力学性能进行了探讨,发现氧化度10%的复合水凝胶48h后的溶胀率达1 777%,断裂强度为0.11MPa,随着OSA氧化度的增大,OSA/PAM复合水凝胶的溶胀率增大,而拉伸强度逐渐减小。     

双氯灭痛壳聚糖水凝胶微球的制备及其性能研究

在Span80与植物油形成的反相胶束体系中,通过戊二醛交联制备出壳聚糖水凝胶微球(CHM)。采用红外光谱和透射电镜等方法对CHM结构及粒子形态进行了研究。同时对CHM的溶胀度及其对模型药物双氯灭痛的体外释放行为进行了考察。结果表明,CHM具有较好的控制药物释放的作用。交联程度对微球粒径、溶胀度及药物释放性能影响较大。     

海藻酸钠/碳纳米管复合凝胶球的制备及其吸附性能

提出一种安全简单污水处理的方法,以物理共混的方法利用海藻酸钠分散未经任何处理的原始多壁碳纳米管,得到均匀分散的海藻酸钠/碳纳米管(SA/MWNTs)水溶液,以CaCl2作为凝固浴,制备SA-Ca和SA/MWNTs-Ca复合凝胶球,利用凝胶球对甲基橙(MO)溶液进行吸附脱色研究。试验结果表明:海藻酸钠凝胶球对甲基橙去除率较低,随着碳纳米管含量的增加,当MWNTs增加到2.5g/L,SA/MWNTs-Ca凝胶球的吸附性能提高了3倍;并且随着凝胶球量的增加,去除率迅速增加,当凝胶球质量浓度从1～50g/L时,去除率有显著提高,增加近10倍;溶液pH值对吸附性能的研究还表明,溶液的pH值对SA/MWNTs-Ca凝胶球的吸附性能有较大的影响,pH值较低时有利于SA/MWNTs-Ca凝胶球对MO的吸附。     

Preparation and characterization of oxidized alginate covalently cross-linked galactosylated chitosan scaffold for liver tissue engineering

Liver tissue engineering (LTE) requires a perfect extracellular matrix (ECM) for hepatocytes culture to maintain high level of liver-specific functions. Here, we reported a LTE scaffold derived from oxidized alginate covalently cross-linked galactosylated chitosan via Schiff base reaction, without employing any extraneous chemical cross-linking agent. The structure of galactosylated chitosan (GC) and oxidized alginate was confirmed by Fourier transformed infrared (FTIR) spectra, proton nuclear magnetic resonance (¹H-NMR) spectroscopy, X-ray diffraction (XRD) or thermogravimetric (TG) analysis. The structure and properties of a series of the scaffolds were characterized by FTIR, XRD, scanning electron microscopy (SEM), porosity, equilibrium swelling, mechanical properties, thermal stability and in vitro degradation. FTIR spectra confirmed the characteristic peak of Schiff base groups in the scaffolds and XRD indicated the scaffolds could be amorphous. SEM analysis showed that the scaffolds displayed highly porous surfaces with average pore size of 50-150 μm and interconnected pore structure in the internal structure with average pore size of 100-250 μm. Porosity measurement suggested the scaffolds had a porosity of about 70%. The compressive modulus of the scaffolds (hydrated) was in the range of 4.2-6.3 kPa. Further studies showed that, with the increase of the oxidized alginate content, the equilibrium swelling and in vitro degradation rate of the scaffolds decreased and the thermal stability slightly increased, which might mainly attribute to the difference of the degree of cross-linking and the nature properties of the raw materials. Additionally, the biocompatibility of the scaffolds was evaluated in vitro. The results showed that the hepatocytes cultured on the scaffolds had a typical spheroidal morphology, formed multi-cellular aggregates and presented perfect integration with the scaffolds, which suggested that the scaffolds may be potential candidates for LTE strategies.     

Investigating preparation and characterisation of diphtheria toxoid‐loaded on sodium alginate nanoparticles

This paper aims to investigate the preparation and characterisation of the alginate nanoparticles (NPs) as antigen delivery system loaded by diphtheria toxoid (DT). For this purpose, both the loading capacity (LC) and Loading efficiency (LE) of the alginate NPs burdened by DT are evaluated. Moreover, the effects of different concentrations of sodium alginate and calcium chloride on the NPs physicochemical characteristics are surveyed in addition to other physical conditions such as homogenization time and rate. To do so, the NPs are characterised using particle size and distribution, zeta potential, scanning electron microscopy, encapsulation efficiency, in vitro release study and FT‐IR spectroscopy. Subsequently, the effects of homogenization time and rate on the NPs are assessed. At the meantime, the NPs LC and efficiency in several DT concentrations are estimated. The average size of the NPs was 400.7 and 276.6 nm for unloaded and DT loaded, respectively. According to the obtained results, the zeta potential of the blank and DT loaded NPs are estimated as −23.7 mV and −21.2 mV, respectively. Whereas, the LC and LE were >80% and >90%, in that order. Furthermore, 95% of the releasing DT loaded NPs occurs at 140 h in the sustained mode without any bursting release. It can be concluded that the features of NPs such as morphology and particle size are strongly depended on the calcium chloride, sodium alginate concentrations and physicochemical conditions in the NPs formation process. In addition, appropriate concentrations of the sodium alginate and calcium ions would lead to obtaining the desirable NPs formation associated with the advantageous LE, LC (over 80%) and sustained in vitro release profile. Ultimately, the proposed NPs can be employed in vaccine formulation for the targeted delivery, controlled and slow antigen release associated with the improved antigen stability.     

磷虾蛋白/海藻酸钠/聚乙烯醇复合纳米纤维的制备及表征

以磷虾蛋白(AKP)、海藻酸钠(SA)、聚乙烯醇(PVA)为纺丝原料,通过静电纺丝制备AKP/SA/PVA复合纳米纤维,系统研究了纺丝液浓度和纺丝电压对纤维形貌的影响。通过FT-IR分析复合纤维的结构,结果表明SA与AKP间存在化学反应,而与PVA是物理共混,通过红外的二阶导数和拟合分峰研究共混纤维间的氢键作用,结果表明氢键的类型及含量与纤维构成有关。通过DSC和TGA测试纳米纤维的热性能,表明纤维在250℃左右开始熔融并伴随着分解。     

海藻酸钠-胰蛋白酶微球的制备及药物释放性能

通过离子凝胶法制备出球形完好的海藻酸钠-胰蛋白酶微球.红外分析表明,微球中凝胶基质通过海藻酸钠的-COO-与Ca2+发生静电作用交联形成.SEM观察显示微球中存在蛋格结构及孔洞.考察了不同因素对微球载药率、包封率和体外释药率的影响.结果表明,海藻酸钠水溶液浓度越高释药率越低,当海藻酸钠与胰蛋白酶质量比为4,海藻酸钠水溶...     

Preparation of chitosan–sodium alginate microcapsules containing ZnS nanoparticles and its effect on the drug release

Chitosan–sodium alginate microcapsules were prepared in the presence of ZnS nanoparticles via the W/O/W emulsification solvent-evaporation method. Microscopy showed that the microsphere was about 150 nm and by the absorption spectra, ZnS nanoparticles incorporated was 4 nm. Aspirin was chosen to investigate the effect of microcapsules on the drug release. It reveals that comparing with the microsphere without nanoparticles, the release speed of microsphere containing ZnS nanoparticles is significantly decreased from complete release at 10 h to 50% release by 50 h. The data of release kinetics for the microcapsules can be well fitted by the classic Higuchi model.     

海藻酸钠/聚乙烯醇共混膜的制备及表征

用溶液共混法制备海藻酸钠/聚乙烯醇(SA/PVA)共混膜,并对其进行了IR、DSC表征和吸水率、透气率、力学性能等测定.结果表明,在这种由两种可生物降解的高聚物共混而成的共混膜中,PVA与SA分子链间有一定的相互作用,相容性好;共混膜有较高的抗水性和较好的综合力学性能.     

In Situ Gelling Pectin Formulations for Oral Sustained Delivery of Paracetamol

The purpose of this study was to evaluate the potential of a pectin formulation with in situ gelling properties for the oral sustained delivery of paracetamol (acetaminophen). The formulations consisted of dilute aqueous solutions (1% to 2% w/v) of low methoxy pectin containing calcium ions in complexed form, which on release in the acidic environment of the stomach caused gelation of the pectin. In vitro studies demonstrated diffusion‐controlled release of paracetamol from the gels over a period of 6 h. A bioavailability of approximately 96% of that of a paracetamol solution could be achieved from gels containing an identical dose of drug formed in situ in the stomachs of rats, with appreciably lower peak plasma levels and a sustained release of drug over a period of at least 6 h.     

Oral sustained delivery of paracetamol from in situ gelling xyloglucan formulations

The purpose of this study was to evaluate the potential of a xyloglucan formulation with in situ gelling properties for the oral sustained delivery of paracetamol. Gelation of dilute aqueous solutions of the polysaccharide xyloglucan occurred in rabbit and rat stomachs as the orally administered chilled solutions attained body temperature. In vitro studies demonstrated diffusion-controlled release of paracetamol from the gels over a period of 6 hr. The bioavailabilities of paracetamol from the xyloglucan gels formed in situ in the stomachs of rabbits after oral administration of the liquid formulations were similar to that of a commercially available suspension containing an identical dose of paracetamol.     

In situ gelling pectin formulations for oral sustained delivery of paracetamol

The purpose of this study was to evaluate the potential of a pectin formulation with in situ gelling properties for the oral sustained delivery of paracetamol (acetaminophen). The formulations consisted of dilute aqueous solutions (1% to 2% w/v) of low methoxy pectin containing calcium ions in complexed form, which on release in the acidic environment of the stomach caused gelation of the pectin. In vitro studies demonstrated diffusion-controlled release of paracetamol from the gels over a period of 6 h. A bioavailability of approximately 96% of that of a paracetamol solution could be achieved from gels containing an identical dose of drug formed in situ in the stomachs of rats, with appreciably lower peak plasma levels and a sustained release of drug over a period of at least 6 h.     

反应pH值对原位水热沉积法制备纳米羟基磷灰石/壳聚糖复合材料的影响

为避免羟基磷灰石(HA)在壳聚糖(CS)基体中分子出现分布不均的现象,在结合原位沉析法和水热法二者优点的基础上,发展了原位水热沉析法来制备HA/CS复合材料,并深入研究不同的反应pH值对该复合材料的影响。研究表明,在不同反应pH值下制备的复合材料,均由CS晶体和低结晶度的纳米HA晶体所组成,2种晶体均出现沿c轴方向上的择优生长。随着反应pH值的增大,复合材料中HA和CS分子的结晶度均增大,HA晶体尺寸增大,CS分子排列有序化程度增高,且二者之间发生较强的化学键合作用。当反应pH值增大到12时,复合材料中纳米HA的晶体尺寸约为27.63 nm,且均匀地分布在CS分子中;CS分子为高结晶度的α晶型,且分子排列规整,有序化程度高;存在于HA与CS分子间的化学键合作用最强。     

海藻酸钠/纤维素水凝胶球的制备与应用

利用基于p H值反转的落球法制备出不同质量分数的纤维素和海藻酸钠复合水凝胶球,并采用扫描电子显微镜(SEM)和傅里叶变换红外光谱(FTIR)对凝胶样品的形貌和化学态进行表征。结果表明海藻酸钠含量≤50%时凝胶球可以保持稳定的球形结构,内部为纤维链交叉聚集的三维网络多孔结构。复合凝胶球对亚甲基蓝、金胺O和臧红T等阳离子染料有着良好的吸附效果,含有50%海藻酸钠凝胶球对亚甲基蓝的吸附量为163.36 mg/g,吸附过程满足准二阶动力学方程,经过5次吸附脱附实验后仍然保持初始81%的吸附量。因此,该复合凝胶球可以作为一种低成本的生物吸附剂用于染料处理领域。     

A novel wet-spinning method of manufacturing continuous bio-inspired composites based on graphene oxide and sodium alginate

Nacre is a lightweight, strong, stiff, and tough material, which makes it a mimicking object for material design. Many attempts to mimic nacre by various methods resulted in the synthesis of artificial nacre with excellent properties. However, the fabrication procedure was very laborious and time-consuming due to the sequential steps, and only limited-sized materials could be obtained. Hence, a novel design enabling scalable production of high-performance artificial nacre with uniform layered structures is urgently needed. We developed a novel wet-spinning assembly technique to rapidly manufacture continuous nacremimic graphene oxide (GO, brick)-sodium alginate (SA, mortar) films and fibers with excellent mechanical properties. At high concentrations, the GO-SA mixtures spontaneously produced liquid crystals (LCs) due to the template effect of GO, and continuous, 6 m long nacre-like GO-SA films were wet-spun from the obtained GO-SA liquid crystalline (LC) dope with a speed of up to 1.5 m/min. The assembled macroscopic GO-SA composites inherited the alignment of the GO sheets from the LC phase, and their mechanical properties were investigated by a joint experimental-computational study. The tensile tests revealed that the maximum strength (σ) and Young’s modulus (E) of the obtained films reached 239.6 MPa and 22.4 GPa, while the maximum values of σ and E for the fibers were 784.9 MPa and 58 GPa, respectively. The described wet-spinning assembly method is applicable for a large-scale and fast production of high-performance continuous artificial nacre.

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