DNA interaction,anti-proliferative effect of copper oxide nanocolloids prepared from metallosurfactant based microemulsions acting as precursor,template and reducing agent

In the present study, we have synthesized mixed cuprous/copper oxide nanosuspensions by metallosurfactant based microemulsion technique. Three metallosurfactants were synthesized which includes two non-ionic double chained metallosurfactants with C₁₂, C₁₆ chains with coordinated copper i.e. Cudda and Cuhexa, respectively. Another cationic double chained metallosurfactant with loosely bound metal (Cuctac) was also prepared. The prepared metallocomplexes were characterized using FTIR, elemental analysis, and NMR. The effect of the position of metallosurfactant in microemulsion on the fabrication and properties of nanosuspensions was elucidated. In this method, no external reducing agent and capping agent were added and tween 80 acted both as reducing and stabilizing agent for the nanoparticles. The synthesized nanoparticles were characterized and it was observed that mixed copper and cuprous oxide particles are present in colloidal suspension for all the three studied metallosurfactants. The kinetics of formation of mixed copper/cuprous oxide nanosuspensions (Ns) and their stability was estimated using Uv-visible spectroscopy. Further, the binding and interactions of copper nanosuspensions with calf Thymus DNA (CT-DNA) were assessed using Uv–vis spectroscopy, circular dichroism and gel electrophoresis. Additionally, the antioxidant activity of the Cu Ns was checked using DPPH assay. The role of positive charge on nanoparticles as evaluated from Zeta potential was responsible for DNA affinity. The DNA conformational changes in the presence of nanosuspensions and relevant scavengers were investigated. Further, the anti-proliferative activity of copper Ns was assessed using HeLa cells and Cuhexa derived Ns were proved to be active with highest activity at a low concentration and were nontoxic towards normal cell lines. In summary, this work demonstrates a softer approach for the synthesis of copper nanosuspensions with a size range of 2–5?nm and evaluated the role of type and structure of metallosurfactant on size, stability of particles and anti-proliferative activity.     

Lipid based nanocarriers: a translational perspective

Over the recent couple of decades, pharmaceutical field has embarked most phenomenal noteworthy achievements in the field of medications as well as drug delivery. The rise of Nanotechnology in this field has reformed the existing drug delivery for targeting, diagnostic, remedial applications and patient monitoring. The convincing usage of nanotechnology in the conveyance of medications that prompts an extension of novel lipid-based nanocarriers and non-liposomal systems has been discussed. Present review deals with the late advances and updates in lipidic nanocarriers, their formulation strategies, challenging aspects, stability profile, clinical applications alongside commercially available products and products under clinical trials. This exploration may give a complete idea viewing the lipid based nanocarriers as a promising choice for the formulation of pharmaceutical products, the challenges looked by the translational process of lipid-based nanocarriers and the combating methodologies to guarantee the headway of these nanocarriers from bench to bedside.     

Amphiphilic association systems for Amphotericin B delivery

The present study describes the production and characterization of amphiphilic association systems for Amphotericin B (AMB). In particular, three different classes of microemulsions and different monoglyceride–water systems were produced. Formulations were characterized for macroscopic aspect, pH, rheology, mean size and size distribution, both in the absence and in the presence of AMB.

AMB solubility was investigated in the different formulations by HPLC studies. The formulations increased AMB solubility up to 20-fold with respect to the single oil and aqueous phases employed for microemulsion production.

AMB diffusion studies from two microemulsions taken as models were performed in a Franz cell system using a nylon membrane.

The physical and chemical stability of AMB-containing amphiphilic association systems were investigated for three months after production. For physical stability studies both the macroscopic aspect, droplet mean size and dimensional distribution were analysed. For chemical stability studies, the AMB content of the formulations was quantified by HPLC analysis. Microemulsions and monoglyceride–water systems were free from phase separation for up to three months and in some cases the AMB content was unchanged even after three months.     

Development of ultra fast liquid chromatographic method for simultaneous determination of nitrendipine and carvone in skin diffusate samples

A simple and sensitive reverse phase ultra fast liquid chromatographic (UFLC) method for simultaneous determination of nitrendipine and carvone in skin diffusate samples and microemulsions was developed and validated. The separation was achieved using a gradient mobile phase, on an Onyx column. The eluents were monitored by photodiode array detection. The linearity ranges of proposed method were 0.125–50 μg mL⁻¹ and 0.125–30 μg mL⁻¹ for nitrendipine and carvone respectively. The intra-day and inter-day coefficient of variation and percent error values of the assay method were less than 10%. The method was found to be precise, accurate, and specific during the study. The method was successfully applied for simultaneous estimation of nitrendipine and carvone in ex vivo skin diffusate samples and microemulsions.     

Cremophor RH40-PEG 400 microemulsions as transdermal drug delivery carrier for ketoprofen

The aim of this study was to prepare novel microemulsion for transdermal drug delivery of ketoprofen (KP). The microemulsion composed of ketoprofen as model drug, isopropyl myristate (IPM) as oil phase, surfactant mixture consisting of polyoxyl 40 hydrogenated castor oil (Cremophor RH40) as surfactant and polyethylene glycol 400 (PEG400) as co-surfactant at the ratio 1:1, and water were prepared. The viscosity, droplet size, pH, conductivity of microemulsions, and skin permeation of KP through shed snake skin were evaluated. The particle size, pH, viscosity and conductivity of microemulsions were in the range of 114-210 nm, 6.3-6.8, 124-799 cPs and 1-45 μS/cm, respectively. The ratio of IPM, and surfactant mixture played the important role in the skin permeation of KP microemulsions. As the amount of surfactant mixture and IPM increased, the skin permeation of KP decreased. The formulation composed of 30% IPM, 45% surfactant mixture and 25% water showed the highest skin permeation flux. The incorporation of terpenes in the 2.5% KP microemulsions resulted in significant enhancement in skin permeation of KP. The rank order of enhancement ratio for skin permeation enhancement of terpenes was α-pinene > limonene > menthone. The results suggested that the novel microemulsion system containing IPM, water, Cremophor RH40:PEG400 and terpenes can be applied for using as a transdermal drug delivery carrier.     

白藜芦醇微乳的制备及表征

目的:采用高压均质法制备白藜芦醇微乳,并对其进行表征。方法:以白藜芦醇微乳粒径分布、多分散系数(Pd I)、包封率为评价指标,考察制备白藜芦醇微乳的各个因素,并对制得的微乳进行表征;初步研究白藜芦醇微乳的稳定性。结果:白藜芦醇微乳的平均粒径为231±37.8 nm,Pd I为0.228±0.047,zeta电位为-42.5±4.3 m V;透射电镜显示微乳粒径均一,成球状分布。长期稳定性研究显示,微乳在25℃条件下放置3个月稳定。结论:高压均质法制备白藜芦醇微乳工艺简单易行。     

丹参酮微乳制备工艺的初选及优化

目的寻找丹参酮微乳最佳的处方和制备工艺。方法选择大豆磷酯与F-68为乳化剂,甘油和山梨醇为辅助乳化剂。通过单因素实验初选,均匀设计优化处方和制备工艺。结果优化条件下,制备的丹参酮微乳为淡红色透明胶体溶液,平均粒径为42.1 nm,包封率为98.47%,载药量为0.468%。结论该优化条件可作为丹参酮微乳最佳的处方和制备工艺。     

甲氧沙林皮肤用微乳的制备及体外透皮研究

目的：制备甲氧沙林微乳透皮给药系统,对其体外理化性质及透皮行为进行考察。方法：分别以聚氧乙烯蓖麻油为非离子型表面活性剂,无水乙醇为助表面活性剂,油酸乙酯为油相,水相溶液逐滴加入油相的方法制备甲氧沙林微乳,并对其形态、粒径大小及分布,稳定性等进行了考察。采用Valia—Chien水平扩散池考察微乳的体外透皮过程。结果：制得的甲氧沙林微乳为淡黄色透明液体,平均粒径（90．5±8．2）nm。12h的累积释放量为（1023．00±56．92）μg·cm^-1。结论：甲氧沙林微乳质量稳定,具有良好的体外透皮效果,值得进一步研究。     

Mechanism of stereoselective production of trans-1-decalone by electrochemical catalysis in microemulsions

Microemulsions made from water, oil and surfactant are attractive alternatives to organic solvents for mediated electrochemical synthesis. Cyclization of 2-(4-bromobutyl)-2-cyclohexen-1-one (1) to 1-decalone (2) mediated by an electrochemically generated cobalt(I) complex favored the trans- form over cis-1-decalone by about 93:7 in microemulsions, but poorer stereoselectivity was obtained in organic solvents. Microemulsion composition, surfactant type (cationic or anionic), or chirality of the mediator did not significantly influence the trans/cis ratio of 1-decalone. Selective formation of trans-1-decalone in microemulsions is attributed to equilibration of isomers via keto-enol tautomerization catalyzed by hydroxide ions formed by co-electrolysis of water during the reaction. Trans-1-decalone was efficiently produced in 2 h electrolyses in microemulsions with large volume fractions of water. Organic solvents with trace amounts of water gave little stereoselectivity over similar periods, but longer equilibration times produced larger proportions of trans-1-decalone.     

In vitro studies of the hemolytic activity of microemulsions in human erythrocytes

Hemolytic activity in human erythrocytes as alternative to in vivo testing was used as a potential screening method to evaluate irritant potential of microemulsions for possible application in pharmaceutical and cosmetic formulations. Microemulsions were prepared by mixing surfactants and oil and slowly titrating the mixtures with aliquots of phosphate buffer saline or water. All microemulsions were characterized by dynamic light scattering to determine both the mean droplet size and droplet distribution. Microemulsion droplet size decreased as aqueous component increased. No differences in droplet size were observed between formulations containing phosphate buffered saline or water. The hemolytic activity was measured photometrically by the RBC assay, based in the cell membrane lysis, to estimate the potential irritation of both surfactants and microemulsions selected with water or PBS as aqueous component. The most hemolytic microemulsions corresponded to those containing the surfactant Labrasol^®, with or without butyl lactate, and no differences were found between the hemolytic activity between these components and microemulsions containing them. The highest hemolytic activity of microemulsions in this study may be attributed to the excipient used in the formulations. We should avoid the use of high amounts of Labrasol^® and butyl lactate in microemulsions because they may be potential irritants.