Thermosensitive mucoadhesive gel formulation loaded with 5-Fu: cyclodextrin complex for HPV-induced cervical cancer

Human Papilloma Virus (HPV) infections are the major cause of cervical cancers. To achieve a better therapeutic efficacy and patient compliance in the treatment for HPV-induced cervical cancers, anticancer agent 5-fluorouracil has been formulated in a vaginal gel using the thermosensitive polymer Pluronic^® F127 together with alternative mucoadhesive polymers e.g., hyaluronic acid, Carbopol 934 and hydroxypropylmethylcellulose. To increase its aqueous solubility and to achieve the complete release of 5-FU from the gel, the drug was incorporated as its inclusion complex with 1:1 molar ratio with either β-cyclodextrin or hydroxypropyl-β-cyclodextrin. Following the characterization of drug:CD complexes, thermosensitive gel formulations containing different mucoadhesive polymers and the drug in free or complexed form were characterized in vitro by determining the gelation temperature and the rheological behavior of different formulations along with the in vitro release profiles of these formulations in pH 5.5 citrate buffer. It was observed that complexation with cyclodextrin accelerated the release of 5-FU with the exception of formulation containing Carbopol 934 as mucoadhesive polymer. As far as rheological properties are concerned, favorable thermosensitive in situ gelling properties were obtained with formulations containing HPMC as mucoadhesive polymer. Complete release of 5-FU from gels were obtained with both complexes of β-CD and HP-β-CD and cytotoxicity studies against HeLa human cervical carcinoma cells demonstrated that 1% 5-FU:CD complexes were equally effective as 1% free 5-FU indicating better therapeutic efficacy with lower dose.     

抗肿瘤药物在金属有机骨架中的装载及体外释放

以三乙胺直接加入法制备金属-有机骨架MOF-5, 采用X射线粉末衍射(XRD), 红外光谱(IR)和热重分析(TG)对所得样品进行表征. 分别以辣椒素和5-氟尿嘧啶(5-Fluouourail, 5-FU)为模型药物, 研究了MOF-5对2种药物的载药及体外释药性能. 通过将所得样品的XRD和IR谱图与标准谱图比对确定了样品的结构. TG结果表明, 所制备的MOF-5热稳定性良好. MOF-5对辣椒素的最高载入量达0.592 g/g载体, 对5-FU的最高载入量为0.315 g/g载体, 两种载药体系的体外释药均为明显的两相模式. 体外细胞毒性实验结果表明, MOF-5具有良好的生物相容性.     

PDTC和5-氟尿嘧啶对人鼻咽癌细胞株CNE1、CNE - GL、CNE2Z的联合作用

为观察PDTC和5-氟尿嘧啶在体外对人鼻咽癌细胞株CNE1、CNE - GL、CNE2Z的联合抑制效应,采用MTT法测定了5- FU组、PDTC组、5- FU联合PDTC组、先5- FU后PDTC组、先PDTC后5- FU组、阴性对照组和空白对照组对CNE1、CNE - GL、CNE2Z三种细胞的生长抑制率;采用直线回...     

New solid mucoadhesive systems for benzydamine vaginal administration

The aim of this work was the realization of new formulations for vaginal application to improve the pharmacological effect of benzydamine, displaying both anti-inflammatory and antiseptic activities. For this reasons, this drug was formulated in solid dispersions, by using the mucoadhesive polymers HPMC and/or Carbopol(?), then compressed. Tablets were characterized by studies of friability, hardness, hydration, DSC, mucoadhesion and in vitro release. Kinetics, responsible for drug delivery, was investigated as well. Tablets prepared by using only HPMC showed the best results in terms of swelling and mucoadhesion (time and force) together with prolonged and complete drug release, by diffusive mechanism, through gelled layer. Despite the good mucoadhesive properties, Carbopol(?) does not represent a good excipient because, after the contact with water, it generates a spongy gel layer, not homogeneous, stiff, brittle and with breaking tendency when highly swelled. This kind of gel does not guarantee a linear drug release and could provoke discomfort because of fragment release. HPMC mucoadhesive tablets could be a proper delivery system for benzydamine administration representing a good alternative to traditional dosage forms for vaginal topical therapy.     

β-cyclodextrin/alginate nanoparticles encapsulated 5-fluorouracil as an effective and safe anticancer drug delivery system

Although 5-Fluorouracil (5-FU) is one of the most frequently used cytotoxic chemotherapy drugs in the treatment of cancer, it possesses a short biological half-life and toxic side effects against normal healthy cells. In this work, β-cyclodextrin/alginate (β-CD/Alg) nanoparticles loaded with 5-fluorouracil (5-FU) were prepared to evaluate release properties and bioactivity in different pH media. Stable nanocomposites with the best loading efficiency (36%) and encapsulation efficiency (90%) were successfully fabricated. The size of the nanocomposite solution was determined via dynamic light scattering (DLS) to be in the range 30–120 nm with a mean size of 70 nm, while TEM images showed the particle size of the nanocomposite to be in the range 30–80 nm with a mean size of 50 nm. The release profile of 5-FU in a simulated gastric fluid (pH 1.2) was much lower than in a simulated colorectal fluid (pH 7.4). The release behaviour of 5-FU from the nanocomposite was confirmed by the change in morphology in the pH media. A cytotoxicity assay indicated that the nanocomposite is an effective delivery system for 5-FU with strong antiproliferative activity against MCF-7 cells and negligible effects on normal healthy cells.     

Modified PLA nano in situ gel: a potential ophthalmic drug delivery system

A novel nano in situ gel forming system of 5-Fluorouracil (5-FU) was investigated for its potential use for conjunctival/corneal squamous cell carcinoma (CCSC). The study was conducted in two steps, in the first step PLA nanoparticles were prepared and characterized; in the second step the drug loaded PLA nanoparticles were dispersed in sodium alginate solution yielding the modified nano in situ system, which were evaluated in rabbit eye. Size and morphology of prepared PLA particles were verified by using dynamic light scattering (DLS), atomic force microscope (AFM) and scanning electron microscope (SEM). In vitro and in vivo study of free 5-FU, PLA nanoparticles and modified nano in situ system were conducted in simulated tear fluid and in rabbit eye respectively. PLA nanoparticles were in size range of 128-194 nm with spherical shape and smooth surface with narrow size distribution. No polymer drug interaction was found as confirmed by FTIR, NMR and DSC. XRD of PLA nanoparticles confirmed that 5-FU was present in the crystalline state. In vitro experiments indicated a diffusion controlled release of 5-FU from both PLA nanoparticles and modified nano in situ system with high burst effect. Modified nano in situ gel system (MNS) significantly increased the Cmax and AUC0-8 in aqueous humor as compared to 5-FU solution and PLA nanoparticles. Higher 5-FU level in aqueous humor was possibly because of increased retention time of gel matrix-embedded drug loaded nanoparticles. Overall results showed the potential of MNS for ophthalmic delivery in the therapy of CCSC.     

聚乳酸包载5-氟尿嘧啶靶向超微粒子对人胃癌转移瘤的靶向性和控制释放研究

使用w／o／w复乳法制备聚乳酸载5-氟尿嘧啶超微粒子,使用透射电镜、激光粒度仪和紫外分光光度计对超微粒子进行表征,并考察其体外释药性质。将^99mTc标记的连有VEGF121单克隆抗体的超微粒子通过尾静脉注射到SCID裸鼠体内,观察它对胃癌转移瘤的靶向效果和治疗效果。结果显示超微粒子成圆球形,平均粒径为195.2nm,多分散系数为0.148,靶向载药超微粒子的载药率为8．23％,包封率为24．71％。聚乳酸载5-Fu超微粒子在PBS缓冲溶液中具有较好的控释效果,累积释放量Q与时间平方根t^1/2基本呈线性关系．尾静脉注射靶向超微粒子两小时以后可看到大部分超微粒子集中到肿瘤部位。在所有的实验组中,含5-Fu靶向载药超微粒子组的疗效最好,说明本靶向载药超微粒子具有抑制肿瘤的血管生成并在肿瘤组织释放化疗药物抑制肿瘤生长的双重作用。     

聚乙二醇相对分子质量及用量对温敏型PCL-PEG-PCL水凝胶的制备及释药性研究

采用开环聚合法制备PCL-PEG-PCL共聚物,并将其制成温敏性水凝胶,探究了PEG(聚乙二醇)相对分子质量及质量浓度对水凝胶温敏性的影响.水凝胶的相变温度由翻转小瓶法测定.通过FTIR、热分析仪和SEM等技术对其组成及结构进行表征.以疏水性姜黄素(Cur)为模型药物,制备出载Cur PCL-PEG-PCL水凝胶,并研究其体外释药行为.FTIR结果表明:实验制备的共聚物中含有PCL和PEG的链段.热分析结果表明:在25℃~65℃内水凝胶存在相变过程.SEM结果表明:水凝胶剖面具有疏松多孔.体外释药结果表明:PCL-PEG-PCL水凝胶对Cur具有缓释作用,释药机理符合Higuchi骨架溶蚀模型.     

Preparation and properties of inhalable nanocomposite particles for treatment of lung cancer

Nanoparticles have widely been studied in drug delivery research for targeting and controlled release. The aim of this article is application of nanoparticles as an inhalable agent for treatment of lung cancer. To deposit effectively deep the particles in the lungs, the PLGA nanoparticles loaded with the anticancer drug 6-{[2-(dimethylamino)ethyl]amino}-3-hydroxyl-7H-indeno[2,1-c]quinolin-7-one dihydrochloride (TAS-103) were prepared in the form of nanocomposite particles. The nanocomposite particles consist of the complex of drug-loaded nanoparticles and excipients. In this study, the anticancer effects of the nanocomposite particles against the lung cancer cell line A549. Also, the concentration of TAS-103 in blood and lungs were determined after administration of the nanocomposite particles by inhalation to rats.TAS-103-loaded PLGA nanoparticles were prepared with 5% and 10% of loading ratio by spray drying method with trehalose as an excipient. The 5% drug-loaded nanocomposite particles were more suitable for inhalable agent because of the sustained release of TAS-103 and higher FPF value. Cytotoxicity of nanocomposite particles against A549 cells was higher than that of free drug.When the nanocomposite particles were administered in rats by inhalation, drug concentration in lung was much higher than that in plasma. Furthermore, drug concentration in lungs administered by inhalation of nanocomposite particles was much higher than that after intravenous administration of free drug.From these results, the nanocomposite particle systems could be promising for treatment of lung cancer.     

Nasal in situ gel containing hydroxy propyl ��-cyclodextrin inclusion complex of artemether: development and in vitro evaluation

The objective of the present investigation was to explore the formulation and evaluation of in situ gel for the nasal delivery of artemether (ARM), a poorly water-soluble antimalarial agent using temperature induced gelation technique using Pluronic with mucoadhesive polymer Hydroxy Propyl Methyl Cellulose (HPMC) K4M in different ratios. Initially, due to low water solubility, an inclusion complex of the antimalarial artemether (ARM) in hydroxypropyl-??-cyclodextrin (HP??CD) was prepared and characterized. The in situ gels so prepared were characterized for its gelation properties, viscosity, gel strength, mucoadhesion, drug content, drug release rate and for its histopathological studies. Pluronic and HPMC based in situ gel (PLH2) showed the effective gelation, viscosity, gel strength and drug release properties along with good mucoadhesive strength, it is further subjected for stability studies carried out at 30 ± 2 °C and 60 ± 5% RH for 90 days in order to know the influence of temperature and relative humidity on drug content and on drug release profile. Histological examination of formulations did not show any remarkable damage to nasal mucosa. The formulation also retained the good stability at accelerated conditions over the period of 90 days. Owing to these properties it can be used as an effective delivery system for the nasal route. These in situ gelling systems would be definitely useful for cerebral malaria.     

Thermosensitive Gels for the Topical Administration of Diltiazem

In the present work, thermosensitive systems were prepared, characterized, and proposed for diltiazem administration in the topical treatment of anal fissures. Methylcellulose and PluronicF127 were used as gelling polymers. Some low-toxicity molecules, such as sodium glycocholate, citric acid, and lactic acid, were added to gel formulations as counterions to enhance diltiazem lipophilicity. The systems were characterized by sol-gel transition temperature, viscosity, and rheological studies. The resulting data allowed us to determine which systems presented sol-gel transition. A change from Newtonian to plastic behavior at sol-gel transition temperature was observed. An increase in diltiazem pig skin permeability and two-fold skin accumulation was observed in the presence of citric acid.     

Thermosensitive hydrogel coatings: Synthesis and heparin release

The synthesis and drug release properties of crosslinked N-isopropylacrylamide (NiPAAm) copolymer coatings on the surface of a hydrophobic poly(ester-urethane) tubing were examined. A method was designed to coat hydrophobic polymer surface with a thermosensitive gel layer. Crosslinked NiPAAm copolymer coatings were synthesized using UV-initiated polymerization. The feasibility of using NiPAAm based gels as heparin releasing thermosensitive coatings was investigated. Heparin, a high molecular weight hydrophilic solute, was loaded into hydrogels using a simple solution sorption technique. The release of heparin from NiPAAm copolymer gel coatings was compared to that of crosslinked NiPAAm copolymers. The gel coatings demonstrated a more gradual and prolonged heparin release as compared to gel disks of the same composition.     

Structural organization of plasma membrane lipids isolated from cells cultured as a monolayer and in tissue-like conditions

In this paper, folate conjugated poly(ε-caprolactone-co-4-maleate-ε-caprolactone) (P(CL-co-MCL)-folate) was prepared by a carbodiimide coupling reaction, i.e., the vitamin folic acid (FA) was covalently linked to the main chain of the maleate-functionalized polymer, poly(ε-caprolactone-co-4-maleate-ε-caprolactone) (P(CL-co-MCL)). Then the 5-Fluorouracil (5-FU) loaded nanoparticles of P(CL-co-MCL)-folate were achieved by solvent-evaporation method. Their properties were extensively studied by dynamic light scattering (DLS) and scan electron microscopy (SEM). DLS and SEM showed that the nanoparticles were in a well-defined spherical shape with a uniform size distribution. We also investigated the entrapment and in vitro release behavior, which indicated that the release speed of 5-FU could be well controlled and the release half-life period could reach 16.86h, which was 26.4 times longer than that of pure 5-FU. The in vitro targeting test displayed that the 5-FU loaded P(CL-co-MCL)-folate nanoparticles exhibited an enhanced cell inhibition because folate targeting increased the concentration of 5-FU loaded P(CL-co-MCL)-folate nanoparticles in the tumor cells with folate receptor overexpressed. Meanwhile, the tumor inhibition of 5-FU loaded P(CL-co-MCL)-folate nanoparticles was much higher than that of pure 5-FU and that of 5-FU loaded P(CL-co-MCL) nanoparticles. Therefore, P(CL-co-MCL)-folate nanoparticles would be highly beneficial for biomedical and pharmaceutical applications.     

The influence of chitosan on cyclodextrin complexing and solubilizing abilities towards drugs

The present work was performed to investigate the effect of chitosan, a well known hydrophilic polymer with both enhancer and solubilizing properties, on the solubilizing and complexing abilities of cyclodextrins towards drugs. With this aim, phase-solubility studies were carried out with a series of model drugs, both of acid and basic nature and with different water-solubility and lipophilicity values, in the presence of chitosan and cyclodextrin (ß- or hydroxypropyl-ß-cyclodextrin), both separately (binary systems) and in combination (ternary systems). Unexpectedly, differently from the favorable effect reported in literature for various hydrophilic polymers, the addition of chitosan to the cyclodextrin complexation medium caused a decrease in the cyclodextrin complexing power towards all the examined drugs, independent from their very different physicochemical properties. On the contrary, the influence of the polymer on the cyclodextrin solubilizing efficiency was found to be dependent on the type of drug and both positive, or negative or non-significant effects were observed. The overall results are explained in terms of a common basic mechanism due to the presence of chitosan–cyclodextrin interactions, which hindered the drug–cyclodextrin complex formation, thus causing the binding constant reduction; the simultaneous presence of drug–chitosan and/or chitosan–(drug–cyclodextrin complex) interactions, different from drug to drug, were considered responsible for the distinct (and sometimes opposite) effects observed in the drug solubilizing efficiency of ternary systems.     

Preparation and characterization of m PEG grafted chitosan micelles as 5-fluorouracil carriers for effective anti-tumor activity

The objective of this study was to investigate the potential of methoxy polyethylene glycol（m PEG）grafted chitosan（m PEG-g-CS） to be used as a drug carrier. m PEG-g-CS was successfully synthesized by one-step method with formaldehyde. The substitution degree of m PEG on chitosan was calculated by elemental analysis and was found to be（3.23 0.25）%. m PEG-g-CS self-assembled micelles were prepared by ultrasonic method with the controlled size of 178.5–195.1 nm and spherical morphology. Stable dispersion of the micelles was formed with the zeta potential of 2.3–30.2 m V. 5-Fluorouracil（5-FU）, an anticancer chemotherapy drug, was used as a model drug to evaluate the efficiency of the new drug delivery carrier. The loading efficiency of 5-FU was（4.01 0.03）%, and the drug-loaded m PEG-g-CS self-assembled micelle showed a controlled-release effect. In summary, the m PEG-g-CS self-assembled micelle is proved to be a promising carrier with controlled particle size and controlled-release effect. Therefore, it has great potential for the application as 5-FU carriers for effective anti-tumor activity.     

Influence of spray-dried hydroxyapatite-5-fluorouracil granules on cell lines derived from tissues of mesenchymal origin

In our previous work we described the preparation and characterization of spray dried hydroxyapatite micro granules loaded with 5-fluorouracil (5-FU). These loaded particles are used as a model drug delivery system (DDS). In this study we examined the in vitro response of two cell lines derived from different tissues to 5-FU loaded granules (LG). Both cell lines, either L929 cells of a mouse fibroblast lineage or cells originating from a rat osteosarcoma (ROS 17/2.8) showed a dose dependent decrease in cell proliferation in response to 5-FU-, either dissolved in the culture medium or loaded onto particles. The response of the two cell lines to loaded and nonloaded particles was different. The effect of LG and of a corresponding concentration of free 5-FU was practically the same for the ROS 17/2.8 cells indicating that ROS 17/2.8 cells were not affected by the carrier material. In contrast, L929 cells showed a slight decrease in cell proliferation also in the presence of granules not loaded with 5-FU. This is thought to be attributed to the inhibition of mitogenesis by phosphocitrates, already demonstrated in fibroblasts. In summary, we found that the loaded 5-FU kept its effectivity after the spray drying process and that the response towards the granules varied with cell type. This is the first step towards a tissue specific DDS.     

Effect of Andrographis paniculata leaf extract on wound healing in rats

This work was carried out to study the effect of topical application of Andrographis paniculata on the rate of wound enclosure and its histological features. A wound was created in four groups of rat in posterior neck region. Blank placebo was applied topically to the wounds of Group 1. Groups 2 and 3 were dressed with placebo containing 5% and 10% extracts of A. paniculata, respectively. Intrasite gel was applied topically to the wounds of Group 4. Macroscopical examination revealed that the rate of wound healing was significantly accelerated in the wound dressed with A. paniculata extract compared to the blank placebo. The wounds dressed with 10% extract or Intrasite gel healed earlier compared to the wounds dressed with placebo containing 5% A. paniculata extract. Histologically, wounds dressed with A. paniculata extracts showed markedly less scar width and contained large amounts of fibroblast proliferation. More collagen and less angiogenesis with absence of inflammatory cells were seen for wounds dressed with 10% A. paniculata compared to the blank placebo. Conclusion, A. paniculata extracts significantly enhanced rate of wound healing in rats.     

Microemulsions for intravesical delivery of gemcitabine

The objective of this work was to develop a safe and effective delivery vehicle for topical treatment of gemcitabine. The physicochemical properties, drug release rate, drug level in plasma and bladder, and histological changes of tissue after drug administration were investigated. The electrical conductivity, mean size, and viscosity of drug-loaded microemulsions were 0.8-102.0 μS/cm, 116.8-322.5 nm, and 42.9-105.0 cps×103, respectively. Gemcitabine loaded microemulsions showed a slower and sustained release. After intravesical administration of aqueous control and microemulsions treated, the drug concentrations in plasma were 15.11 μg/ml and 2.81-12.82 μg/ml, respectively, and the accumulation in bladder were 18.27 μg and 9.12-64.16 μg, respectively. Microemulsions slightly decreased the systemic absorption and significantly enhanced the accumulation in bladder tissue. Moreover, the preliminary toxicity studies revealed no overt adverse histological changes or tissue irritation by the microemulsion application. Therefore, the microemulsions were suggested to be a promising drug carrier for intravesical chemotherapy.     

Chitosan and a modified chitosan as agents to improve performances of mucoadhesive vaginal gels

New mucoadhesive formulations were designed and studied in order to improve local vaginal therapy by increasing formulation retention prolonging thus drug-mucosa contact time. Some gels were prepared using hydroxyethylcellulose (HEC) alone or mixed with chitosan (CS) or its derivative 5-methyl-pyrrolidinone-chitosan (MPCS) and were loaded with the antibacterial metronidazole (MET) (0.75%). All formulations showed pseudoplastic flow and viscosity increase was observed proportionally to chitosan content (CS>MPCS). Prepared gels showed better extrusion properties (yield stress) than market formulation Zidoval. Mucoadhesion force studies permitted to point out that: (i) CS decreases mucoadhesion force; (ii) MPCS addition increases the mucoadhesion force at high percentage; (iii) all gels containing chitosan showed better mucoadhesive performances than Zidoval. Gels containing MPCS showed higher and faster drug release than those containing CS. All the preparations were able to release higher drug amounts if compared to market formulation. In conclusion MPCS improved gel characteristics in terms of mucoadhesion force, rheological behaviour and drug release pointing out that this modified chitosan is very suitable to obtain manageable and more acceptable vaginal formulation.     

Formulation and evaluation of gel containing nanostructured lipid carriers of tretinoin–Epi-β-CD binary complex for topical delivery

The objective of present research work was to formulate and evaluate topical gel containing tretinoin–cyclodextrin (CD) binary complex loaded into nanostructured lipid carriers (NLCs). Use of cyclodextrin and nanolipid carrier together in a system produced a synergistic effect by increasing the drug release and skin permeation, thus improving the overall therapeutic effect. Two different cyclodextrins i.e. β-CD and its water soluble polymeric derivative epichlorohydrin-β-cyclodextrin (EPI-β-CD) were used to obtain binary inclusion complex of drug-cyclodextrin (D-CD) systems by two different techniques (kneading and co-evaporation). The prepared solid complexes were characterized by FTIR, DSC, XRD etc. and the best system was selected for loading into nanolipid carriers. NLC comprising glyceryl mono stearate (GMS) and oleic acid were obtained by slightly modified emulsification evaporation method. Four different formulations of NLCs were suitability characterized for particle size, zeta potential, entrapment efficiency, drug loading and drug release. EPI-β-CD was found to be more effective than β-CD in enhancing solubility and dissolution properties of tretinoin. The most effective NLC formulation was incorporated into carbopol hydrogel which showed better permeation properties than that of the reference gel (0.1%).