N-trimethyl chitosan-modified liposomes as carriers for oral delivery of salmon calcitonin

Therapeutic peptide and protein drugs have high specificity and activity in their functions but present challenges in their administration route, requiring development of new delivery systems to improve their bioavailability. The aim of this work was to investigate the role of N-trimethyl chitosan- (TMC-) coated liposomes in the oral administration of calcitonin. TMC with a degree of quaternization around 78% was synthesized and its mucoadhesive properties were examined in vitro using the mucin-particle method, which confirmed that TMC showed mucoadhesion comparable to that of chitosan. TMC-coated liposomes containing calcitonin were prepared and characterized as having a particle size of 262?nm, zeta potential of 35.8 mV and high entrapment efficiency (89.1%). The in vivo evaluation of mucoadhesion was carried out using confocal laser microscopy to observe the residence time and permeation extent after intragastric administration. The results showed that TMC-coated liposomes prolonged the residence time and increased the penetration effect of the liposomal system compared to non-coated liposomes. The study of pharmacological effects confirmed that TMC-coated liposomes increased the area above the blood calcium concentration-time curves (AAC) from 3.13?±?20.50 to 448.84?±?103.56 compared to the calcitonin solution. These results support the feasibility of TMC-coated liposomes as a new oral delivery system for peptide and protein drugs.     

盐酸环丙沙星栓剂的处方改进及质量控制

目的改进盐酸环丙沙星栓的处方并建立其质量控制方法。方法采用热熔法制备栓剂,采用高效液相色谱法测定环丙沙星的含量。结果以醋酸缓冲液制备的盐酸环丙沙星栓处方较好,含量合格。结论改进的处方及制备工艺合理,质量控制方法简单、快速、准确。     

紫外分光光度法测定盐酸环丙沙星滴眼液的含量

采用紫外分光光度法测定盐酸环丙沙星滴眼液的含量,测定波长为277nm,平均回收率为99.4%,CV=0.09%。     

荧光分光光度法测定盐酸环丙沙星片的含量

采用荧光分光光度法测定盐酸环丙沙星片的含量简便、快速、灵敏度高。线性范围为０．１～０．５μｇ／ｍｌ，平均回收率为１００．０４％，相对标准差为０．６０％。     

盐酸吡硫醇脂质体在大鼠体内药动学研究

目的 研究盐酸吡硫醇脂质体注射液在大鼠体内的药动学行为,并与盐酸吡硫醇注射液进行比较,评价盐酸吡硫醇脂质体药动学特征。方法 采用大鼠股静脉给药,眼眶取血,UPLC/MS/MS法测定大鼠血浆中盐酸吡硫醇的浓度,运用MasslynxTM NT4.1软件进行数据采集;运用QuanLynxTM program进行数据分析。结果 脂质体及溶液剂的AUC0-t分别为（1817.093±197.832）、（2592.349±303.194）μg/(L?h);Cmax分别为（6080.502±549.12）、（9525.987±531.813）μg/L;t1/2分别（1.512±0.387）、（0.732±0.388）h。两制剂的药时过程均符合三隔室模型,两者药动学行为相似。结论 运用DAS2.0进行生物等效性评价,脂质体组与溶液剂组药动学参数均在等效置信区间内,两制剂生物等效。     

Utilization of propranolol hydrochloride mucoadhesive invasomes as a locally acting contraceptive: in-vitro,ex-vivo,and in-vivo evaluation

It was found that propranolol hydrochloride (PNL), which is a beta-blocker used for hypertension treatment, has a potent spermicidal activity through local anesthetic activity or beta-blocking effect on sperm cells subsequently it could be used as a contraceptive remedy. This study aimed to entrap PNL into invasomes (INVs) and then formulate it as a locally acting contraceptive gel. PNL-loaded mucoadhesive INVs were prepared via the thin-film hydration technique. The D-optimal design was utilized to fabricate INVs employing lipid concentration (X₁), terpenes concentration (X₂), terpenes type (X₃), and chitosan concentration (X₄) as independent variables, while their impact was observed for entrapment efficiency percent (Y₁; EE%), particle size (Y₂; PS), zeta potential (Y₃; ZP), and amount of drug released after 6 h (Y₄; Q6h). Design Expert® was bestowed to nominate the desired formula. The selected INV was subjected to further studies and formulated into a mucoadhesive gel for ex-vivo and in-vivo investigations. The optimum INV showed a spherical shape with EE% of 65.01 ± 1.24%, PS of 243.75 ± 8.13 nm, PDI of 0.203 ± 0.01, ZP of 49.80 ± 0.42 mV, and Q6h of 53.16 ± 0.73%. Differential scanning calorimetry study asserted the capability of INVs to entrap PNL. Permeation studies confirmed the desired sustained effect of PNL-loaded INVs-gel compared to PNL-gel, INVs, and PNL solution. Sperm motility assay proved the potency of INVs-gel to inhibit sperm motility. Besides, the histopathological investigation verified the tolerability of the prepared INVs-gel. Taken together, the gained data justified the efficacy of PNL-loaded INVs-gel as a potential locally acting contraceptive.     

Hypoglycemic efficacy of chitosan-coated insulin liposomes after oral administration in mice

INTRODUCTION In the past two decades the potential usefulnessof liposomes as drug carriers for improving enteral ab-sorption of poorly absorbed drugs including peptidedrugs such as insulin has attracted considerable interest.These phospholipid vesicles are capable of encapsulat-ing both hydrophobic and hydrophilic drugs; they arebiodegradable and are not toxic in vivo. The drugsencapsulated in liposomes are sufficiently protectedfrom enzymatic attack and immune recognition[1]. Li-po…     

Ocular application of chitosan

Introduction: A major problem in ocular therapeutics with classical formulations is the maintenance of an effective drug concentration at the site of action for a long period of time. Enhancement of ocular bioavailability with increased dose penetration and longer retention time at desired sites can be achieved by recent formulations. Chitosan stands out with its unique structural advantageous characteristics for different types of formulations like in situ gelling systems, micro- and nanoparticles, inserts, etc.

Areas covered: In this review, the authors focus on ocular therapeutics and the characteristics that make chitosan more acceptable in ocular applications.

Expert opinion: Chitosan seems to be one of the most promising polymeric carriers for both hydrophilic and lipophilic drugs for ocular application.     

In vitro and in vivo evaluation of targeting efficiency of Adriamycin hydrochloride magnetic microspheres

The objective of this study was to prepare magnetic microspheres as a targeting drug delivery system and to specifically evaluate its targeting efficiency. The magnetic microspheres were prepared by emulsion cross-linking techniques. Targeting efficiency was specifically investigated by experiments of biodistribution on rats and histological study. Adriamycin hydrochloride (ADR)-loaded magnetic microspheres were successfully prepared with the mean diameter of 3.853 μm (± 1.484 μm), and had its speciality of superparamagnetism. The results of the targeting efficiency study showed that application of the external magnetic field significantly increased the ADR concentration from 40.28 μg/ml to 100.70 μg/ml at 10?min, 36.99 μg/ml to 91.16 μg/ml at 60?min, and 13.71 μg/ml to 28.30 μg/ml at 180?min in liver as the targeting tissue. The relative uptake efficiencies in liver by injection treatment of ADR magnetic microspheres with external magnetic field were 3.87, 5.59, and 3.34 at 10?min, 60?min, and 180?min after administration, respectively. In conclusion, distinguished targeting efficiency was displayed, which indicated that the magnetic microspheres could be applied as a novel targeting drug delivery system.     

N-三甲基壳聚糖包衣阿霉素脂质体与普通脂质体的抗肿瘤活性比较

目的:比较N-三甲基壳聚糖(TMC)包衣的盐酸阿霉素(ADM)脂质体与普通ADM脂质体的抗肿瘤活性。方法:采用硫酸铵梯度法制备ADM脂质体,以不同取代度的TMC进行包衣,采用动物移植性肿瘤实验法,用小鼠H22肝癌细胞接种于小鼠右侧腋下皮下形成实体瘤,考察TMC包衣ADM脂质体和普通脂质体给药后对实体瘤的瘤重抑制率。结果:TMC60、TMC40、TMC20包衣ADM脂质体对小鼠H22肝癌移植瘤的抑瘤率分别为64.3%,57.0%和54.8%,显著高于ADM脂质体组和游离ADM组(36.4%、42.7%)(P<0.05)。结论:TMC包衣ADM脂质体具有较好的抗肿瘤活性。     

盐酸莫西沙星脂质体的制备及包封率测定方法研究

目的：制备盐酸莫西沙星脂质体,建立盐酸莫西沙星脂质体包封率测定方法。方法：乙醇注入法制备盐酸莫西沙星脂质体,正交试验优选脂质体的最佳处方。采用葡聚糖凝胶柱法、超滤离心法分离脂质体与游离药物,并进行方法学考察,优选出测定盐酸莫西沙星脂质体包封率的方法。结果：盐酸莫西沙星脂质体的最佳处方为：卵磷脂与胆固醇比为 3：1,药脂比为 1：7,水合介质中聚山梨酯20的用量为1%,优化后的包封率为90.73%。葡聚糖凝胶柱法和超滤离心法都能将脂质体与游离药物分离,葡聚糖凝胶柱法的平均柱加样回收率为85.54%~88.15%,超滤离心法的平均加样回收率为94.40%~97.35%。结论：盐酸莫西沙星脂质体的制备工艺稳定,包封率较高。葡聚糖凝胶柱法不适于盐酸莫西沙星脂质体的包封率测定,超滤离心法可高效、准确、方便地测定盐酸莫西沙星脂质体包封率。     

盐酸环丙沙星壳聚糖纳米粒原位凝胶的制备与评价

目的 制备盐酸环丙沙星壳聚糖纳米粒原位凝胶,并评价其抑菌及创面愈合效果。方法 采用复乳法制备盐酸环丙沙星壳聚糖纳米粒,采用2因素2水平全因子析因实验设计考察了壳聚糖相对分子质量（X₁）和壳聚糖质量浓度（X₂）对壳聚糖纳米粒的药物包封率（Y₁）、粒径分布（Y₂）、多分散系数（Y₃）和Zeta电位（Y₄）的影响;并以泊洛沙姆407作为凝胶基质制备盐酸环丙沙星壳聚糖纳米粒原位凝胶。通过抑菌圈实验比较盐酸环丙沙星乳膏和盐酸环丙沙星壳聚糖纳米粒原位凝胶对金黄色葡萄球菌和铜绿假单胞菌的抑菌活性;使用无菌活检穿刺针在大鼠背部造成直径为5 mm的皮肤全切除的圆形人工创面,并使用金黄色葡萄球菌和铜绿假单胞菌的培养基感染24 h,建立大鼠创面模型,将模型大鼠随机分为模型组、盐酸环丙沙星乳膏组和盐酸环丙沙星壳聚糖纳米粒原位凝胶组,模型组大鼠创面未接受任何处理,给药组大鼠每2天给药1次,每次给药量均约为1 mg,观察并记录每组大鼠创面脱痂时间和愈合时间。结果 选择低相对分子质量壳聚糖、壳聚糖质量浓度为2.0 mg·mL^-1制备盐酸环丙沙星壳聚糖纳米粒,其中盐酸环丙沙星质量浓度为50.0 mg·mL^-1,其包封率为（85.3±0.9）%,平均粒径为（354.7±15.7）nm,PDI为0.357±0.014,Zeta电位为（22.2±0.5）mV,呈球状分布;盐酸环丙沙星壳聚糖纳米粒原位凝胶和盐酸环丙沙星乳膏对金黄色葡萄球菌的抑菌圈直径分别为（38.4±0.2）、（29.2±0.3）mm,对铜绿假单胞菌抗菌圈直径分别为（41.3±0.6）、（32.1±0.1）mm;大鼠创面给予盐酸环丙沙星壳聚糖纳米粒原位凝胶后,其脱痂时间和愈合时间均较模型组和盐酸环丙沙星乳膏组显著缩短（P<0.05）。结论 成功制备盐酸环丙沙星壳聚糖纳米粒原位凝胶,其可以抑制创面细菌繁殖、加速伤口愈合。     

Muco-adhesive multivesicular liposomes as an effective carrier for transmucosal insulin delivery

Considering limitations of conventional insulin therapies, the present study characterizes usefulness of novel mucoadhesive multivesicular liposomes as a mucoadhesive sustained release carrier of insulin via nasal and ocular routes, thus attempts to develop non-invasive carrier system for the controlled release of bioactives. Multivesicular liposomes (MVLs) of 26–34 μm were prepared with a high protein loading (58–62%) and were coated with chitosan and carbopol. These mucoadhesive carriers were characterized by zeta potential studies, in vitro mucoadhesion test and insulin protective ability against nasal aminopeptidase. In vitro, mucoadhesive carriers released insulin for a period of 7–9 days compared to 24 h of conventional liposomes. After intranasal administration to STZ induced diabetic rats, the mucoadhesive MVLs (chitosan coated MVLs) effectively reduced plasma glucose level up to 2 days (35% reduction), compared to non-coated MVLs (32% at 12 h) and conventional liposomes (34% at 8 h). Although the differences are statistically insignificant, chitosan coated formulation has shown a better hypoglycemic profile as the effects were prolonged compared to carbopol coated formulation. When compared to ocular route, chitosan formulation after nasal administration has shown better therapeutic profile as the hypoglycemic effects were prolonged until 72 h. The effectiveness of this chitosan coated MVLs was further demonstrated by the significant quantities of ELISA detectable insulin levels after nasal (334.6 μIu/ml) and ocular (186.3 μIu/ml) administration. These results demonstrate that mucoadhesive carrier is a viable option for a sustained release transmucosal insulin carrier, and open an avenue to develop a non-invasive carrier platform for the controlled release of bioactives.     

Gastroretentive mucoadhesive tablet of lafutidine for controlled release and enhanced bioavailability

Abstract

Lafutidine a newly developed histamine H2-receptor antagonist having biological half-life of 1.92?±?0.94?h due to its selective absorption from upper part of gastrointestinal tract the development of mucoadhesive sustained release drug delivery system is recommended in order to enhance the bioavailability. A mucoadhesive tablets was developed using the natural polymer, sodium alginate, xanthan gum and karaya gum. Mucoadhesion is a complex phenomenon which involves wetting, adsorption and interpenetration of polymer chains. The prepared tablets of various formulations were evaluated for a total mucoadhesion time, buoyancy lag time and percentage drug released. The formulation with xanthan gum showed better results. Thus, it may be useful for prolonged drug release in stomach to improve the bioavailability and reduced dosing frequency. Non-fickians release transport was confirmed as the drug release mechanism from the optimized formulation by Korsmeyer–Peppas. The optimized formulation (B3) showed a mucoadhesive strength >35?g. In vivo study was performed using rabbits by X-ray imaging technique. Radiological evidences suggest that, a formulated tablet was well adhered for >10?h in rabbit’s stomach. Optimized lafutidine mucoadhesive tablets showed no significant change in physical appearance, drug content, mucoadhesive properties and in vitro dissolution pattern after storage at 40?°C temperature 75?±?5% relative humidity for 3 months.     

盐酸利多卡因多囊脂质体的制备和质量评价

目的:制备具有缓释特性的盐酸利多卡因多囊脂质体,考察其理化性质。方法:以卵磷脂和胆固醇为膜材,采用复乳法制备盐酸利多卡因多囊脂质体,用透射电镜观察其外观形态,用激光粒度分析仪测定粒径,检测包封率和体外释药特性。结果:盐酸利多卡因多囊脂质体的外观形态圆整、规则,粒径分布在300～700nm及1～6μm两区域,包封率为(27.10±0.66)%。多囊脂质体在pH 7.4的磷酸盐缓冲液中,24h的累积释药百分率为(92.7±3.6)%。结论:盐酸利多卡因多囊脂质体具有一定的缓释特性。     

Preparation of chitosan-coated liposomes as a novel carrier system for the antiviral drug Triazavirin

Abstract

Novel method for the coating of positively charged liposomes with modified chitosan was elaborated. Liposomes were prepared by stepwise extrusion through inorganic membranes (Anotop) of 0.2 and 0.1?μm pore sizes. Chitosan derivatives were synthesized via the Ugi multicomponent reaction. Several series of liposomal compositions were produced and their properties were compared in terms of particle size, polydispersity index (PDI), zeta potential and stability. The effect of various additives was investigated and the optimal composition of the lipid film was determined. The addition of the uncharged fatty esters allowed the diameter of the liposomes obtained by extrusion to be reduced to 145–150?nm with a PDI of 0.13–0.15. The prepared liposomes were loaded with the novel antiviral drug Triazavirin and used to determine the release profile. Triazavirin was included into liposome layer as a salt with biocompatible choline derivatives of limiting fatty acids. The appropriate lipid composition was used for the preparation of a larger quantity of liposomes coated by modified chitosan. It was shown that an appropriate combination of liposomes and polysaccharide layer potentially extended colloidal stability by up to 3 months and exhibited broad functional capabilities for surface modification.     

Electrosteric stealth Rivastigmine loaded liposomes for brain targeting: preparation,characterization, ex vivo,bio-distribution and in vivo pharmacokinetic studies

Being one of the highly effective drugs in treatment of Alzheimer’s disease, Rivastigmine brain targeting is highly demandable, therefore liposomal dispersion of Rivastigmine was prepared containing 2?mol% PEG-DSPE added to Lecithin, Didecyldimethyl ammonium bromide (DDAB), Tween 80 in 1:0.02:0.25 molar ratio. A major challenge during the preparation of liposomes is maintaining a stable formulation, therefore the aim of our study was to increase liposomal stability by addition of DDAB to give an electrostatic stability and PEG-DSPE to increase stability by steric hindrance, yielding what we called an electrosteric stealth (ESS) liposomes. A medium nano-sized liposome (478?±?4.94?nm) with a nearly neutral zeta potential (ZP, ?8?±?0.2?mV) and an entrapment efficiency percentage of 48?±?6.22 was prepared. Stability studies showed no major alteration after three months storage period concerning particle size, polydispersity index, ZP, entrapment efficiency and in vitro release study confirming the successful formation of a stable liposomes. No histopathological alteration was recorded for ESS liposomes of the sheep nasal mucosa. While ESS liposomes showed higher % of drug permeating through the sheep nasal mucosa (48.6%) than the drug solution (28.7%). On completing the in vivo pharmacokinetic studies of 36 rabbits showed 424.2% relative bioavailability of the mean plasma levels of the formula ESS compared to that of RHT intranasal solution and 486% relative bioavailability of the mean brain levels.     

聚中性红薄膜修饰电极测定盐酸环丙沙星含量

目的 研究聚中性红薄膜修饰电极（PNRE）对盐酸环丙沙星（CPLX）的电催化作用，建立一种定量检测CPLX的电化学分析方法。方法 利用循环伏安法（CV）电聚合制备PNRE，在0．2mol／LNaN03＋0．0Gmol／LCH3COOH-CH3COONa体系中，研究PNRE对盐酸环丙沙星氧化的电催化作用及其定量测定CPLX的最佳条件。结果在7．5×10^-7～7．5×10^-5mol／L范围内，催化氧化峰电流与CPLX的浓度呈良好的线性关系，γ=-0．9999，检测限达3．5×10^-8mol／L，平行测定的RSD小于2.4％（n=8），样品回收率为95．6~103．6％。结论 该法灵敏度高、准确可靠，用于CPLX眼药水及片剂样品的测定取得满意结果。     

齐多夫定棕榈酸酯脂质体的制备及在小鼠体内的药物分布

目的制备齐多夫定棕榈酸酯脂质体并考察其在小鼠体内的分布情况。方法采用乙醇注入法制备齐多夫定棕榈酸酯脂质体;采用HPLC法测定静脉注射后小鼠体内齐多夫定的质量浓度。结果脂质体包封率为95.2%,粒径为(75.6±42.2)nm。小鼠尾静脉分别注射齐多夫定棕榈酸酯脂质体30.0mg.kg-1和齐多夫定溶液15.85mg.kg-1后,体内消除半衰期脂质体组为16.4min,溶液组为5.74min;30min内脂质体组肝、脾、肾和脑(15min内)中齐多夫定的AUC值分别为溶液组的1.6倍、1.19倍、80%、1.8倍。结论采用乙醇注入法制备的齐多夫定棕榈酸酯脂质体包封率高,粒径均匀;可延长药物体内消除半衰期,提高了其在肝和脑的靶向性。齐多夫定棕榈酸酯脂质体有望成为一种理想的抗艾滋病制剂,值得进一步深入研究。     

Absorption-improving effects of chitosan oligomers based on their mucoadhesive properties: a comparative study on the oral and pulmonary delivery of calcitonin

Effects of chitosan oligomers with different types and varying concentrations on the intestinal and pulmonary absorptions of calcitonin were investigated in rats by an in situ closed loop method and an in vivo pulmonary absorption experiment, respectively. Various chitosan oligomers demonstrated different efficiencies in improving the intestinal and pulmonary absorptions of calcitonin, and chitosan hexamer with the optimal concentration of 0.5% (w/v) showed the greatest absorption enhancing effect. Moreover, pharmacodynamic parameters of calcitonin after its coadministration intrapulmonarily with various chitosan oligomers were consistently larger than that in the intestinal delivery, indicating the superior potential of pulmonary administration for systemic delivery of calcitonin. Furthermore, various chitosan oligomers neither obviously increased release amounts of protein nor activities of lactate dehydrogenase (LDH) in bronchoalveolar lavage fluid (BALF), revealing the safety of these chitosan oligomers to lung tissue. In addition, bioadhesions of various chitosan oligomers were well consistent with their absorption enhancing effects in the absorption experiment, suggesting the contribution of mucoadhesive properties of chitosan oligomers to their absorption improving effects. Taken together, chitosan oligomers, especially chitosan hexamer, can effectively improve the intestinal and pulmonary absorptions of calcitonin partly due to the mucoadhesion between positive chitosan oligomers and negative mucus in the membrane.