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PLGA Nanoparticles (plga + nanoparticle)
Selected AbstractsLong circulating nanoparticles of etoposide using PLGA-MPEG and PLGA-pluronic block copolymers: characterization, drug-release, blood-clearance, and biodistribution studiesDRUG DEVELOPMENT RESEARCH, Issue 4 2010Khushwant S. Yadav Abstract The anti-leukemic drug, etoposide (ETO), has variable oral bioavailability ranging from 24,74% with a short terminal half-life of 1.5,h i.v. necessitating continuous infusion for 24,34,h for the treatment of leukemia. In the present study, etoposide-loaded PLGA-based surface-modified nanoparticles (NPs) with long circulation were designed as an alternative to continuous i.v. administration. PLGA-mPEG and PLGA-PLURONIC copolymers were synthesised and used to prepared ETO-loaded NPs by high-pressure homogenization. The mean particle size of ETO-loaded PLGA-MPEG nanoparticles was 94.02±3.4,nm, with an Entrapment Efficiency (EE) of 71.2% and zeta potential value of ,6.9±1.3,mV. ETO-loaded PLGA-pluronic nanoparticles had a mean particle size of 148.0±2.1,nm, an EE of 73.12±2.7%, and zeta potential value of ,21.5±1.6,mV. In vitro release of the pure drug was complete within 4,h, but was sustained up to 7 days from PLGA-mPEG nanoparticles and for 5 days from PLGA-pluronic nanoparticles. Release was first order and followed non-Fickian diffusion kinetics in both instances. ETO and ETO-loaded PLGA nanoparticles labeled with 99mTc were used in blood clearance studies in rats where the two coated NPs, 99mTc- ETO-PLGA-PLU NP and 99mTc- ETO-PLGA-mPEG NP, were found to be available in higher concentrations in the circulation as compared to the pure drug. Biodistribution studies in mice showed that ETO-loaded PLGA-MPEG NP and PLGA-PLURONIC NP had reduced uptake by the RES due to their steric barrier properties and were present in the circulation for a longer time. Moreover, the NPs had greater uptake in bone and brain where concentration of the free drug, ETO, was negligible. Drug delivered from these NPs could result in a single i.v. injection that would release the drug for a number of days, which would be potentially beneficial and in better control of leukemia therapy. Drug Dev Res 71: 228,239, 2010. © 2010 Wiley-Liss, Inc. [source] Technological strategies to improve photostability of a sunscreen agentINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 2 2006P. Perugini Due to the reduction of the ozone layer, there is an increasing need of effective UV protection systems with minimized side-effects. Trans-2-ethylhexyl- p -methoxycinnamate (trans -EHMC) represents one of the most widely used sunscreen compound. Several studies demonstrated that trans -EHMC is unstable following UV irradiation both in solution and in emulsion formulations. Moreover, various reports of photocontact sensitization induced by trans -EHMC have appeared in the literature. Consequently, in order to ensure adequate efficacy and safety for this sunscreen agent, there is a need for new carrier systems to enhance trans -EHMC photostability. In the present study the photostability of the filter in different formulation types (emulsion,gel, gel and emulsion) with various ingredients is evaluated. In addition, nanoparticles based on poly- D,L -lactide-co-glycolide (PLGA) as carrier for trans -EHMC are investigated. The influence of nanoparticle matrix on the photochemical stability of the sunscreen agent is also presented. The results obtained demonstrated that PLGA nanoparticles are effective in reducing the light-induced degradation of the sunscreen agent. Moreover, the choice of formulation type and the excipients used play an important role in order to obtain a stable cosmetic product containing trans -EHMC. [source] Lung-specific delivery of paclitaxel by chitosan-modified PLGA nanoparticles via transient formation of microaggregatesJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 3 2009Rui Yang Abstract Chitosan-modified paclitaxel-loaded poly lactic- co -glycolic acid (PLGA) nanoparticles with a mean diameter of 200,300 nm in distilled water were prepared by a solvent evaporation method. The mean diameter increased dramatically in contact with the mouse (CDF1) plasma, as a function of chitosan concentration in the modification solution (e.g., 2670.5 nm for 0.7% chitosan-modified nanoparticles, NP3), but reverted to almost its original size (i.e., 350.7 nm for NP3) following 5 min of gentle agitation. The zeta potential of PLGA nanoparticles was changed to positive by the chitosan modification. The in vitro uptake into, and cytotoxicity of the nanoparticles against, a lung cancer cell line (A549) were significantly increased by the modification. Most importantly, a lung-specific increase in the distribution index of paclitaxel (i.e., AUClung/AUCplasma) was observed for chitosan-modified nanoparticles (e.g., 99.9 for NP3 vs. 5.4 for TaxolÔ) when nanoparticles were administered to lung-metastasized mice via the tail vein at a paclitaxel dose of 10 mg/kg. Transient formation of aggregates in the blood stream followed by enhanced trapping in the lung capillaries, and electrical interaction-mediated enhanced uptake across the endothelial cells of the lung tumor capillary appear to be responsible for the lung-tumor-specific distribution of the chitosan modified nanoparticles. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:970,984, 2009 [source] Slow-release nanoparticle-encapsulated delivery system for laryngeal injection,THE LARYNGOSCOPE, Issue 5 2010Vasantha L. Kolachala PhD Abstract Objectives/Hypothesis: There is a need for a slow-release system for local delivery of therapeutics to the larynx. Most therapeutic substances, such as steroids or chemotherapeutic agents that are injected into the larynx are cleared rapidly. Repeated laryngeal injection of these substances at short intervals is impractical. Injectable encapsulated poly(lactide-co-glycolide) (PLGA) nanoparticles offer a potential slow-release delivery system for biologically active substances in the larynx. Study Design: Controlled animal study. Methods: PLGA nanoparticles were fabricated using a double emulsion method and were loaded with Texas Red-dextran (NPTR), hepatocyte growth factor (NPHGF), and bovine serum albumin (NPBSA). In vitro release of NPTR, NPBSA, and NPHGF was determined over approximately 2 weeks to assess potential duration of PLGA nanoparticle delivery. In vivo release of NPTR was assessed in a murine vocal fold injection model. The transcriptional effect of NPHGF on procollagen was measured in vitro to assess whether released growth factor retained functionality. Results: In vitro release kinetics demonstrated slow release of NPTR, NPBSA, and NPHGF over 12 to 14 days. In vitro NPTR release correlated with in vivo results. In vivo presence of NPTR occurred up to 7 days compared to 1 day for Texas Red control. In addition, NPHGF ameliorated transforming growth factor-, induced procollagen in vitro in 3T3 fibroblast cells. Conclusions: The results demonstrate the potential utility of nanoparticle encapsulation as an effective method for long-term delivery of specific drugs and biologically active substances to the larynx. Laryngoscope, 2010 [source] Development and validation of a high-performance liquid chromatography method for the simultaneous determination of aspirin and folic acid from nano-particulate systemsBIOMEDICAL CHROMATOGRAPHY, Issue 9 2010Abhishek Chaudhary Abstract Attention has shifted from the treatment of colorectal cancer (CRC) to chemoprevention using aspirin and folic acid as agents capable of preventing the onset of colon cancer. However, no sensitive analytical method exists to simultaneously quantify the two drugs when released from polymer-based nanoparticles. Thus, a rapid, highly sensitive method of high-performance liquid chromatography analysis to simultaneously detect low quantities of aspirin (hydrolyzed to salicylic acid, the active moiety) and folic acid released from biodegradable polylactide-co-glycolide (PLGA) copolymer nanoparticles was developed. Analysis was done on a reversed-phase C18 column using a photodiode array detector at wavelengths of 233,nm (salicylic acid) and 277,nm (folic acid). The mobile phase consisted of acetonitrile,0.1% trifluoroacetic acid mixture programmed for a 30,min gradient elution analysis. In the range of 0.1,100,,g/mL, the assay showed good linearity for salicylic acid (R2 = 0.9996) and folic acid (R2 = 0.9998). The method demonstrated good reproducibility, intra- and inter-day precision and accuracy (99.67, 100.1%) and low values of detection (0.03, 0.01,,g/mL) and quantitation (0.1 and 0.05,,g/mL) for salicylic acid and folic acid, respectively. The suitability of the method was demonstrated by simultaneously determining salicylic acid and folic acid released from PLGA nanoparticles. Copyright © 2009 John Wiley & Sons, Ltd. [source] 2261: Development and evaluation of PLGA nanoparticles with cyclosporine and the inclusion of HP,CD for ocular useACTA OPHTHALMOLOGICA, Issue 2010K HERMANS Ocular delivery of peptides requires new concepts in order to optimize the bioavailability and its therapeutic effect. The first peptide selected in present research project is Cyclosporine A (CyA) used in the treatment of the dry eye syndrome and against corneal graft rejection. The aim of the project is the development of nanoparticles with physicochemical properties for a suitable and prolonged release of CyA, using a factorial design. These drug delivery systems will be produced employing PLGA using the emulsification solvent evaporation method. Positively charged polymers as chitosan or Eudragit® will be incorporated to obtain nanoparticles with a positive particle charge. Electrostatic interactions with the negatively charged mucins lead to a prolonged residence time at the precorneal area. Nanoparticles will be evaluated on zeta potential, particle size and their in vitro drug release properties. CyA and CyA complexed with HP,CD will be compared. The most suitable preparations will be selected in a next phase of the project for an in vivo study using an animal model. [source] | |||||||||||||