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1.
Abstract

The motive behind present work was to discover a solution for overcoming the problems allied with a deprived oral bioavailability of salbutamol sulfate (SS) due to its first pass hepatic metabolism, shorter half-life, and systemic toxicity at high doses. Pulmonary delivery provides an alternative route of administration to avoid hepatic metabolism of SS, moreover facilitated diffusion and prolonged retention can be achieved by incorporation into liposomes. Liposomes were prepared by thin film hydration technique using 32 full factorial design and formulation was optimized based on the vesicle size and percent drug entrapment (PDE) of liposomes. Optimized liposomal formulation exhibited an average size of about 167.2?±?0.170?nm, with 80.68?±?0.74% drug entrapment, and 9.74?±?1.10?mV zeta potential. The liposomal dispersion was then spray dried and further characterized for in-vitro aerosol performance using Andersen Cascade Impactor. Optimized liposomal formulation revealed prolonged in-vitro drug release of more than 90% up to 14?h following Higuchi’s controlled release model. Thus, the proposed new-fangled liposomal formulation would be a propitious alternative to conventional therapy for efficient and methodical treatment of asthma and alike respiratory ailments.  相似文献   

2.
Miconazole nitrate is a widely used antifungal agent, but its use in topical formulations is not efficacious because deep seated fungal infections are difficult to treat with conventional topical formulation. Miconazole nitrate loaded ultraflexible liposomes have been prepared and their topical performance has been compared with conventional liposomes containing miconazole nitrate. Various ultraflexible liposomal formulations were prepared and extensively characterized for vesicular shape, size, entrapment efficiency, degree of deformability and in-vitro skin permeation through rat skin. Higher rate of drug transfer across the skin with ultraflexible liposomal formulations of miconazole nitrate suggests that the drug in its lipo-solubilized state might have gained facilitated entry into the tough barrier consisting of subcutaneous. In-vivo study showed better antifungal activity as compared to traditional liposomes and plain drug solution. This was confirmed through fluoroscence microscopy. It is concluded that prepared ultraflexible liposomes can facilitate improved and localized drug action in the skin, thus providing a better option to deal with deep seated skin problems.  相似文献   

3.
The effects of the liposome form of isoniazide (IN) and liposomes without IN on the growth of Mycobacterium smegmatis were studied. Fluorescent assay demonstrated that the fraction of liposomes that interacted with M. smegmatis amounted to 1–3%. It was shown that the IN efficiency in a liposomal form decreased depending on the liposome composition and concentration as compared with the IN in water solution. A preincubation of mycobacteria with liposomes led to a decrease in their sensitivity to IN. An analogous effect was observed when incubating M. smegmatis with oleic acid. It was postulated that the relative resistance of M. smegmatis to the antibiotic when using lipids as a carbon substrate appeared due to a change in the agent’s metabolism and should be taken into account when testing in vitro the liposomal forms of antibiotics.  相似文献   

4.
The objective of this study was to investigate the potential of liposomes as an ophthalmic delivery system for brinzolamide (Brz) to enhance the local glaucomatous therapeutic effect. The liposomes of Brz (Brz-LPs) were produced by the thin-film dispersion method with a particle size of 84.33?±?2.02 nm and an entrapment efficiency of 98.32?±?1.61%. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) analysis proved that Brz was successfully entrapped into Brz-LPs. Brz-LPs displayed a biphasic release pattern in vitro with burst release initially and sustained release afterwards. The corneal permeability was measured using modified Franz-type diffusion cells, and Brz-LPs showed 6.2-fold increase in the apparent permeability coefficient when compared with the commercial available formulation (B rz-Sus). Moreover, Brz-LPs (1 mg/mL Brz) showed a more sustained and effective intraocular pressure reduction (5–10 mmHg) than Brz-Sus (10 mg/mL Brz) in white New Zealand rabbits. Therefore, Brz-LPs were a hopeful formulation of Brz for glaucoma treatment and worthy of further investigation.  相似文献   

5.
Piroxicam is used in the treatment of rheumatoid arthritis, osteoarthritis, and other inflammatory diseases. Upon oral administration, it is reported to cause ulcerative colitis, gastrointestinal irritation, edema and peptic ulcer. Hence, an alternative delivery system has been designed in the form of transethosome. The present study describes the preparation, optimization, characterization, and ex vivo study of piroxicam-loaded transethosomal gel using the central composite design. On the basis of the prescreening study, the concentration of lipids and ethanol was kept in the range of 2–4% w/v and 0–40% v/v, respectively. Formulation was optimized by measuring drug retention in the skin, drug permeation, entrapment efficiency, and vesicle size. Optimized formulation was incorporated in hydrogel and compared with other analogous vesicular (liposomes, ethosomes, and transfersomes) gels for the aforementioned responses. Among the various lipids used, soya phosphatidylcholine (SPL 70) and ethanol in various percentages were found to affect drug retention in the skin, drug permeation, vesicle size, and entrapment efficiency. The optimized batch of transethosome has shown 392.730 μg cm?2 drug retention in the skin, 44.312 μg cm?2 h?1 drug permeation, 68.434% entrapment efficiency, and 655.369 nm vesicle size, respectively. It was observed that the developed transethosomes were found superior in all the responses as compared to other vesicular formulations with improved stability and highest elasticity. Similar observations were noted with its gel formulation.  相似文献   

6.
长循环紫杉醇纳米脂质体的合成及其活性评估   总被引:1,自引:0,他引:1  
孟淑燕  周彩存  粟波  李玮 《生物磁学》2009,(13):2407-2409
目的:研制甲氧基聚乙二醇二硬脂酰磷脂酰乙醇胺(mPEG2000-DSPE)修饰的长循环紫杉醇纳米脂质体(PEG-PTX-LP),减少市售紫杉醇制剂的不良反应并增强疗效。方法:采用薄膜超声分散法制备PEG-PTX-LP,采用激光散射粒度分析仪和透射电镜观察其物理性状,超滤法检测药物包封率,透析法检测药物缓释能力,通过细胞摄取试验观察人脐静脉内皮细胞(Human Umbilical Vein Endothelial Cells,HUVEC)、A549肺癌细胞对PEG-PTX-LP的摄取能力。结果:透射电镜显示长循环紫杉醇纳米脂质体呈圆形囊泡样结构,粒径检测其平均粒径为99.1 nm,制备后第2、7、14、21、30天的紫杉醇包封率均大于99%,在血清中的缓释能力优于泰素溶液,HUVEC、A549细胞对PEG-PTX-LP中紫杉醇的摄取量明显高于泰素溶液(Taxol)。结论:采用mPEG2000-DSPE修饰的PEG-PTX-LP具有更高的稳定性和缓释能力,对肿瘤细胞和血管内皮细胞有一定的特异性,是一种更有效的紫杉醇新剂型。  相似文献   

7.
Liposomes are potential drug carriers for pulmonary drug delivery: They can be prepared from phospholipids, which are endogenous to the respiratory tract as a component of pulmonary surfactant, and at an appropriate dose liposomes do not pose a toxicological risk to this organ. Among the various categories of drug that benefit from liposomal entrapment is the anti-inflammatory enzyme superoxide dismutase, thus prolonging its biological half-life. The delivery of liposomes by nebulization is hampered by stability problems, like physical and chemical changes that may lead to chemical degradation and leakage of the encapsulated drug. Here we present data of liposomes aerosolized with a novel electronic nebulizer based on a vibrating membrane technology (PARI eFlow?), which amends drawbacks like liposomes degradation and product release. The data acquisition included aerosol properties such as aerodynamic particle size, nebulization efficiency, and liposome leakage upon nebulization. In conclusion, this study shows the ability of the PARI eFlow? to nebulize high amounts of liposomal recombinant human superoxide dismutase with reduced vesicle disruption tested in an enclosing experimental protocol.  相似文献   

8.
To evaluate the possibility of improved drug delivery of quetiapine fumarate (QTP), a nanoemulsion system was developed for intranasal delivery. Effects of different HLBs of Emalex LWIS 10, PEG 400 and Transcutol P, as co-surfactants, were studied on isotropic region of pseudoternary-phase diagrams of nanoemulsion system composed of capmul MCM (CPM) as oil phase, Tween 80 as surfactant and water. Phase behaviour, globule size, transmission electron microscope (TEM) photographs and brain-targeting efficiency of quetiapine nanoemulsion were investigated. In vitro dissolution study of optimised nanoemulsion formulation, with mean diameter 144?±?0.5 nm, showed more than twofold increase in drug release as compared with pure drug. According to results of in vivo tissue distribution study in Wistar rats, intranasal administration of QTP-loaded nanoemulsion had shorter T max compared with that of intravenous administration. Higher drug transport efficiency (DTE%) and direct nose-to-brain drug transport (DTP%) was achieved by nanoemulsion. The nanoemulsion system may be a promising strategy for brain-targeted delivery of QTP.  相似文献   

9.
Silymarin, a known extract, is used in the treatment of liver diseases with various origins, but its current administration form cannot target the liver because of its poor oral bioavailability. A new type of oral silymarin proliposome aimed at improving silymarin’s poor bioavailability and hepatoprotective effects, is introduced in this work. Silymarin-loaded liquid proliposome were prepared using a simple dissolving process. The morphology, particle size, zeta potential, and entrapment efficiency of the silymarin liposomes were analysed. The everted gut sac transport model was used to measure the intestinal transport of liposomes. The liposomal hepatoprotective activity was evaluated in three types of experimental hepatitis animal models. After staining with haematoxylin and eosin, the livers were microscopically examined to analyse any pathological changes. The prepared silymarin proliposome formed silymarin liposomes with a multilayer liposome structure and improved intestinal transport. In an injured liver, the silymarin liposomes produced a stronger hepatoprotective effect through a significant decrease in both the aminotransferase and MDA levels and a significant increase in the SOD and GSH-PX levels compared to orally administered silymarin tablets. This effect was also confirmed histopathologically. In a word, incorporation of silymarin into a liposomal carrier system increased intestinal absorption and showed better hepatoprotective effects compared to silymarin tablets.  相似文献   

10.
Various dressings are available to heal chronic wounds which many times fail to achieve the expected results. To overcome some of their drawbacks, formulation of a novel dressing; lyophilized liposomal wafers having better wound healing potential has been proposed in the present study. The drug incorporated in the formulation is gatifloxacin (GTX) which is a fourth-generation fluoroquinolone antibiotic having in vitro activity against both Gram-negative and Gram-positive bacteria. The formulation was designed in three stages where at first liposomes were prepared, the liposomes were converted to gel using chitosan and lastly this gel was lyophilized to form liposomal wafers. Liposomes were prepared by varying the concentration of lipid and cholesterol and evaluated for particle size, entrapment efficiency, in vitro cumulative release, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Liposomes were converted to liposomal gel using chitosan and evaluated for texture, clarity, viscosity, spreadibility and in vitro drug release. Finally, this liposomal batch was subjected to lyophilization to convert it to liposomal wafers and subjected to SEM, differential scanning calorimetric, X-ray diffraction and drug release studies. The in vivo studies were carried out on Wistar rats where wound healing potential of the wafers was confirmed by histopathological evaluation.  相似文献   

11.
Although liposomal nanoparticles are one of the most versatile class of drug delivery systems, stable liposomal formulation of small neutral drug molecules still constitutes a challenge due to the low drug retention of current lipid membrane technologies. In this study, we evaluate the encapsulation and retention of seven nucleoside analog-based drugs in liposomes made of archaea-inspired tetraether lipids, which are known to enhance packing and membrane robustness compared to conventional bilayer-forming lipids. Liposomes comprised of the pure tetraether lipid generally showed improved retention of drugs (up to 4-fold) compared with liposomes made from a commercially available diacyl lipid. Interestingly, we did not find a significant correlation between the liposomal leakage rates of the molecules with typical parameters used to assess lipophilicity of drugs (such logD or topological polar surface area), suggesting that specific structural elements of the drug molecules can have a dominant effect on leakage from liposomes over general lipophilic character.  相似文献   

12.
Liposomes are potential drug carriers for pulmonary drug delivery: They can be prepared from phospholipids, which are endogenous to the respiratory tract as a component of pulmonary surfactant, and at an appropriate dose liposomes do not pose a toxicological risk to this organ. Among the various categories of drug that benefit from liposomal entrapment is the anti-inflammatory enzyme superoxide dismutase, thus prolonging its biological half-life. The delivery of liposomes by nebulization is hampered by stability problems, like physical and chemical changes that may lead to chemical degradation and leakage of the encapsulated drug. Here we present data of liposomes aerosolized with a novel electronic nebulizer based on a vibrating membrane technology (PARI eFlow), which amends drawbacks like liposomes degradation and product release. The data acquisition included aerosol properties such as aerodynamic particle size, nebulization efficiency, and liposome leakage upon nebulization. In conclusion, this study shows the ability of the PARI eFlow to nebulize high amounts of liposomal recombinant human superoxide dismutase with reduced vesicle disruption tested in an enclosing experimental protocol.  相似文献   

13.
The objective of this study was to develop an ocular drug delivery system built on the cationic liposomes, a novel bioadhesive colloidal system, which could enhance the precorneal residence time, ocular permeation, and bioavailability of ibuprofen. The optimal formulation of cationic liposomes prepared by ethanol injection method was ultimately confirmed by an orthogonal L9 (33) test design. In addition, γ-scintigraphic technology and the microdialysis technique were utilized in the assessment of in vivo precorneal retention capability and ocular bioavailability individually. In the end, we acquired the optimal formulation of ibuprofen cationic liposomes (Ibu-CL) by orthogonal test design, and the particle size and entrapment efficiency (EE%) were 121.0 ± 3.5 nm and 72.9 ± 3.4%, respectively. In comparison to ibuprofen eye drops (Ibu-ED), Ibu-CL could significantly prolong the T max to 100 min and the AUC to 1.53-folds, which indicated that the Ibu-CL could improve the precorneal retention time and bioavailability of ibuprofen. Consequently, these outcomes designated that the ibuprofen cationic liposomes we researched probably are a promising application in ocular drug delivery system.  相似文献   

14.
The pharmacokinetics (PK), biodistribution (BD), and therapeutic activity of pegylated liposomal doxorubicin formulations with different drug release rates were studied in an orthotopic 4T1 murine mammary carcinoma model. The focus of these experiments was to study the effects of different release rates on the accumulation of liposomal lipid and doxorubicin (DXR) into the tumor and cutaneous tissues of mice (skin and paws). These tissues were chosen because the clinical formulation of pegylated liposomal doxorubicin (Caelyx)/Doxi) causes mucocutaneous reactions such as palmar-plantar erythrodysesthesia (PPE). Liposomes with different doxorubicin (DXR) leakage rates were prepared by altering liposome fluidity through changing the fatty acyl chain length and/or degree of saturation of the phosphatidylcholine component of the liposome. Liposomes with fast, intermediate, and slow rates of drug release were studied. The plasma PK of the liposomal lipid was similar for all formulations, while the plasma PK of the DXR component was dependent on the liposome formulation. Liposomal lipid accumulated to similar levels in tumor and cutaneous tissues for all three formulations tested, while the liposomes with the slowest rates of DXR release produced the highest DXR concentrations in both cutaneous tissues and in tumor. Liposomes with the fastest drug release rates resulted in low DXR concentrations in cutaneous tissues and tumor. The formulation with intermediate release rates produced unexpected toxicity that was not related to the lipid content of the formulation. The liposomes with the slowest rate of drug leakage had the best therapeutic activity of the formulations tested.  相似文献   

15.
The aim of the present study was to evaluate the effectiveness of iontophoretic co-delivery of curcumin and anti-STAT3 siRNA using cationic liposomes against skin cancer. Curcumin was encapsulated in DOTAP-based cationic liposomes and then complexed with STAT3 siRNA. This nanocomplex was characterized for the average particle size, zeta-potential, and encapsulation efficiency. The cell viability studies in B16F10 mouse melanoma cells have shown that the co-delivery of curcumin and STAT3 siRNA significantly (p < 0.05) inhibited the cancer cell growth compared with either liposomal curcumin or STAT3 siRNA alone. The curcumin-loaded liposomes were able to penetrate up to a depth of 160 μm inside the skin after iontophoretic (0.47 mA/cm2) application. The in vivo efficacy studies were performed in the mouse model of melanoma skin cancer. Co-administration of the curcumin and STAT3 siRNA using liposomes significantly (p < 0.05) inhibited the tumor progression as measured by tumor volume and tumor weight compared with either liposomal curcumin or STAT3 siRNA alone. Furthermore, the iontophoretic administration of curcumin-loaded liposome-siRNA complex showed similar effectiveness in inhibiting tumor progression and STAT3 protein suppression compared with intratumoral administration. Taken together, cationic liposomes can be utilized for topical iontophoretic co-delivery of small molecule and siRNA for effective treatment of skin diseases.  相似文献   

16.
Although most fungal spores are transported by wind, some remain on lamellae even after fungal fruiting bodies start to decay. This raises the question: are these remaining spores useless or instead transported by other means? In this study, we accordingly investigated whether adult dipteran insects transport fungal spores. Our examination revealed that fungal spores were present in intestines of most drosophilid adults but almost completely absent from those of other dipteran adults. At least some spores excreted by Drosophila angularis and D. brachynephros retained the capacity to germinate. Structural damage to spores that passed through the digestive tract of these two drosophilid species varied among fungal species, with a greater number of colorless spores generally damaged than colored ones. These results suggest that adult drosophilid flies, but not other dipterans, can transport fungal spores.  相似文献   

17.
A scalable and safe method was developed to prepare liposomal carriers for entrapment and delivery of genetic material. The carrier systems were composed of endogenously occurring dipalmitoylphosphatidylcholine (DPPC), negatively charged dicetylphosphate (DCP), cholesterol (CHOL) and glycerol (3%, v/v). Liposomes were prepared by a modified and improved version of the heating method in which no harmful chemical or procedure is involved. Anionic lipoplexes were formed by incorporating plasmid DNA (pCMV-GFP) to the liposomes by the mediation of calcium ions. Transfection efficiency and toxicity of the lipoplexes were evaluated in CHO-K1 cells using flow cytometry and MTT assay, respectively. Controls included DNA-Ca(2+) complexes (without lipids), anionic liposome-DNA complexes (with no Ca(2+)), and a commercially available cationic liposomal formulation. Results indicated fast and reproducible formation of non-toxic lipoplexes that possess long-term stability, high DNA entrapment capacity (81%) and high transfection efficiency. The lipoplex preparation method has the potential of large-scale manufacture of safe and efficient carriers of nucleic acid drugs.  相似文献   

18.
Plasmodium falciparum malaria is responsible for nearly one million annual deaths worldwide. Because of the difficulty in monitoring the pathogenesis of cerebral malaria in humans, we conducted a study in various mouse models to better understand disease progression in experimental cerebral malaria (ECM). We compared the effect on the integrity of the blood brain barrier (BBB) and the histopathology of the brain of P. berghei ANKA, a known ECM model, P. berghei NK65, generally thought not to induce ECM, P. yoelii 17XL, originally reported to induce human cerebral malaria-like histopathology, and P. yoelii YM. As expected, P. berghei ANKA infection caused neurological signs, cerebral hemorrhages, and BBB dysfunction in CBA/CaJ and Swiss Webster mice, while Balb/c and A/J mice were resistant. Surprisingly, PbNK induced ECM in CBA/CaJ mice, while all other mice were resistant. P. yoelii 17XL and P. yoelii YM caused lethal hyperparasitemia in all mouse strains; histopathological alterations, BBB dysfunction, or neurological signs were not observed. Intravital imaging revealed that infected erythrocytes containing mature parasites passed slowly through capillaries making intimate contact with the endothelium, but did not arrest. Except for relatively rare microhemorrhages, mice with ECM presented no obvious histopathological alterations that would explain the widespread disruption of the BBB. Intravital imaging did reveal, however, that postcapillary venules, but not capillaries or arterioles, from mice with ECM, but not hyperparasitemia, exhibit platelet marginalization, extravascular fibrin deposition, CD14 expression, and extensive vascular leakage. Blockage of LFA-1 mediated cellular interactions prevented leukocyte adhesion, vascular leakage, neurological signs, and death from ECM. The endothelial barrier-stabilizing mediators imatinib and FTY720 inhibited vascular leakage and neurological signs and prolonged survival to ECM. Thus, it appears that neurological signs and coma in ECM are due to regulated opening of paracellular-junctional and transcellular-vesicular fluid transport pathways at the neuroimmunological BBB.  相似文献   

19.
A liposomal delivery system that coordinates the release of irinotecan and floxuridine in vivo has been developed. The encapsulation of floxuridine was achieved through passive entrapment while irinotecan was actively loaded using a novel copper gluconate/triethanolamine based procedure. Coordinating the release rates of both drugs was achieved by altering the cholesterol content of distearoylphosphatidylcholine (DSPC)/distearoylphosphatidylglycerol (DSPG) based formulations. The liposomal retention of floxuridine in plasma after intravenous injection was dramatically improved by decreasing the cholesterol content of the formulation below 20 mol%. In the case of irinotecan, the opposite trend was observed where increasing cholesterol content enhanced drug retention. Liposomes composed of DSPC/DSPG/Chol (7:2:1, mole ratio) containing co-encapsulated irinotecan and floxuridine at a 1:1 molar ratio exhibited matched leakage rates for the two agents so that the 1:1 ratio was maintained after intravenous administration to mice. The encapsulation of irinotecan was optimal when copper gluconate/triethanolamine (pH 7.4) was used as the intraliposomal buffer. The efficiency of irinotecan loading was approximately 80% with a starting drug to lipid molar ratio of 0.1/1. Leakage of floxuridine from the liposomes during irinotecan loading at 50 °C complicated the ability to readily achieve the target 1:1 irinotecan/floxuridine ratio inside the formulation. As a result, a procedure for the simultaneous encapsulation of irinotecan and floxuridine was developed. This co-encapsulation method has the advantage over sequential loading in that extrusion can be performed in the absence of chemotherapeutic agents and the drug/drug ratios in the final formulation can be more precisely controlled.  相似文献   

20.
Thymoquinone, the major constituent of Nigella sativa oil has been found to have a promising topical anti-inflammatory activity; however, exaggerated heat and photo-sensitivity and lipophilicity prevent the best use of this promising product. The present work aimed to formulate an ideal thymoquinone liposomal system for topical delivery. Different liposomal systems were developed using thin film hydration method by applying different cholesterol molar concentrations, different total lipid molar concentrations, and different drug-to-lipid ratios. Morphological characterization of the prepared formulae was performed using polarized light, scanning electron microscope, and transmission electron microscope. The optimized formula (F12) was selected on the basis of enhanced permeation through the skin and was incorporated into chitosan gel for topical application. The gel formulation was clear with suitable skin permeation and exhibited acceptable rheological properties. Using carrageenan-induced paw edema in rats, the developed chitosan gel (F12) showed significant superior in vivo anti-inflammatory activity over the chitosan gel of the TQ (p?<?0.05) and comparable effect to the marketed indomethacin gel. As a conclusion, results revealed the potential of formulating thymoquinone as liposomal formulation in enhancing the anti-inflammatory effect compared to the TQ solution.  相似文献   

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