Search results for "MICELLES"
showing 10 items of 233 documents
Tailoring the physicochemical properties of core-crosslinked polymeric micelles for pharmaceutical applications.
2016
To optimally exploit the potential of (tumor-) targeted nanomedicines, platform technologies are needed in which physicochemical and pharmaceutical properties can be tailored according to specific medical needs and applications. We here systematically customized the properties of core-crosslinked polymeric micelles (CCPM). The micelles were based on mPEG-b-pHPMAmLacn (i.e. methoxy poly(ethylene glycol)-b-poly[N-(2-hydroxypropyl) methacrylamide-lactate]), similar to the block copolymer composition employed in CriPec® docetaxel, which is currently in phase I clinical trials. The CCPM platform was tailored with regard to size (30 to 100 nm), nanocarrier degradation (1 month to 1 year) and drug…
Biopartitioning micellar chromatography: an in vitro technique for predicting human drug absorption.
2001
The main oral drug absorption barriers are fluid cell membranes and generally drugs are absorbed by a passive diffusion mechanism. Biopartitioning micellar chromatography (BMC) is a mode of micellar liquid chromatography that uses micellar mobile phases of Brij35 under adequate experimental conditions and can be useful to mimic the drug partitioning process in biological systems. In this paper the usefulness of BMC for predicting oral drug absorption in humans is demonstrated. A hyperbolic model has been obtained using the retention data of a heterogeneous set of 74 compounds, which shows predictive ability for drugs absorbed by passive diffusion. The model obtained in BMC is compared with …
Amphiphilic Copolymers Shuttle Drugs Across the Blood-Brain Barrier.
2015
Medical treatment of diseases of the central nervous system requires transport of drugs across the blood-brain barrier (BBB). Here, it is extended previously in vitro experiments with a model compound to show that the non-water-soluble and brain-impermeable drug domperidone (DOM) itself can be enriched in the brain by use of an amphiphilic copolymer as a carrier. This carrier consists of poly(N-(2-hydroxypropyl)-methacrylamide), statistically copolymerized with 10 mol% hydrophobic lauryl methacrylate, into whose micellar aggregates DOM is noncovalently absorbed. As tested in a BBB model efficient transport of DOM across, the BBB is achievable over a wide range of formulations, containing 0.…
Biopartitioning micellar separation methods: modelling drug absorption
2003
The search for new pharmacologically active compounds in drug discovery programmes often neglects biopharmaceutical properties as drug absorption. As a result, poor biopharmaceutical characteristics constitute a major reason for the low success rate for candidates in clinical development. Since the cost of drug development is many times larger than the cost of drug discovery, predictive methodologies aiding the selection of bioavailable drug candidates are of profound significance. This paper has been focussed on recent developments and applications of chromatographic systems, particularly those systems based on amphiphilic structures, in the frame of alternative approaches for estimating t…
Novel inulin-based mucoadhesive micelles loaded with corticosteroids as potential transcorneal permeation enhancers
2017
In this work a new copolymer of inulin (INU) derivatized with ethylendiamine (EDA) and retinoic acid (RA), named INU-EDA-RA, was synthetized, characterized and employed to produce micelles as carriers for topical administration of corticosteroids for the potential treatment of diseases of posterior eye segment. Spectroscopic analysis confirmed a molar derivatization degree of 11.30 and 4.30% in EDA and RA, respectively. INU-EDA-RA micelles are capable of strong mucoadhesive interactions which result time-independent and stable over time but concentration depending. Moreover micelles are able to encapsulate efficiently from 3 to 13% (w/w) of lipophilic drugs, as dexamethasone, triamcinolone …
A Hyaluronic acid-pentamidine bioconjugate as macrophage mediated drug targeting delivery system for the treatment of Leishmaniasis
2015
Leishmaniasis is still a serious public health problem worldwide, especially in tropical areas where this infectious disease is endemic. The most severe form of the disease (i.e. visceral) can claim victims if left untreated and the few accessible drugs have several drawbacks including major side effects and parenteral administration. In this context, the investigation of new delivery modalities which might reduce the toxicity and increase the bioavailability of the drugs currently on the market represents a valid strategy to counter these problems. Herein we present the development of a macrophage mediated drug targeting delivery system by conjugating the anti-leishmanial drug pentamidine …
Micellization properties of cardanol as a renewable co-surfactant
2015
With the aim to improve the features of surfactant solutions in terms of sustainability and renewability we propose the use of hydrogenated natural and sustainable plant-derived cardanol as an additive to com- mercial surfactants. In the present study we demonstrated that its addition, in amounts as high as 10%, to commercial surfactants of different charge does not significantly affect surfactant properties. Conversely, the presence of hydrogenated cardanol can strongly affect spectrophotometric determination of CMC if preferential interactions with the dyes used take place. This latter evidence may be profitably exploited in surfactant manufacturing by considering that the concurrent pres…
ION MOBILITY STUDIES ON SODIUM-BIS (2- ETHYLHEXIL)SULFOSUCCINATE (AOTNa) AGGREGATES
2012
The supramolecular charged aggregates formed during ESI ionization of AOTNa solutions under critical micelle concentration have been studied thorough ion mobility experiments. In particular, positively charged clusters with several charge states, ranging from +1 to +4, have been investigated. It has been found that, despite to previous investigations (Siuzdak et al. 1995, Nohara et al. 1998), specific ionic aggregates with a peculiar cross section are observed. Indeed a single drift time is observed for each charged aggregate. Using both calculated cross section and experimental calibration curves the experimental cross section of the observed cation has been determined. It is worth noting …
Hidden Structural Features of Multicompartment Micelles Revealed by Cryogenic Transmission Electron Tomography
2014
The demand for ever more complex nanostructures in materials and soft matter nanoscience also requires sophisticated characterization tools for reliable visualization and interpretation of internal morphological features. Here, we address both aspects and present synthetic concepts for the compartmentalization of nanoparticle peripheries as well as their in situ tomographic characterization. We first form negatively charged spherical multicompartment micelles from ampholytic triblock terpolymers in aqueous media, followed by interpolyelectrolyte complex (IPEC) formation of the anionic corona with bis-hydrophilic cationic/neutral diblock copolymers. At a 1:1 stoichiometric ratio of anionic a…
Phospholipid-polyaspartamide micelles for pulmonary delivery of corticosteroids
2011
A novel drug delivery system for beclomethasone dipropionate (BDP) has been constructed through self-assembly of a pegylated phospholipid-polyaminoacid conjugate. This copolymer was obtained by chemical reaction of α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethyleneglycol)2000] (DSPE-PEG(2000)-NH(2)). Benefiting from the amphiphilic structure with the hydrophilic shell based on both PHEA and PEG and many hydrophobic stearoyl tails, PHEA-PEG(2000)-DSPE copolymer was able to self assemble into micelles in aqueous media above a concentration of 1.23 × 10(-7)M, determined by fluorescence studies. During the self-assembling …