Abstract:
:This paper discusses the optimization of the solvent evaporation process to produce double-walled (DW) microspheres in a single-step. Five process variables were studied: polymer solution concentration, polymer weight ratio, polymer solution volume ratios, encapsulation temperature, and air flow rate across the top of the encapsulation vessel. The effects of these variables on the process efficiency (defined here as the percentage of microspheres with a DW configuration compared to the total number of microspheres) were examined. Total polymer concentrations of less than 20% (w/v) produced microspheres with high efficiency, with phase separation consistent across all size fractions in each batch. Changing the volume ratio of the two polymer solutions had no significant effect on the process efficiency. The weight ratio of the polymers greatly influenced the process efficiency, resulting in a low 63% efficiency for the 1:3 Poly-L-lactide (PLLA): Poly(carboxyphenoxypropane-co-sebacic)anhydride 20:80 (P(CPP:SA 20:80)) weight ratio and 0% for the 3:1 weight ratio. The 1:3 weight ratio also caused the polymers to reverse their orientation, although the efficiency for this switch was still relatively low. The temperature of the non-solvent bath affected the efficiency of certain pairs of polymers, but not all. The PLLA/Poly(lactide-co-glycolide) 50:50 (PLGA) pair was most sensitive to temperature, due to the chemical similarity of the two polymers which narrowed the range of acceptable conditions for encapsulation. Pairs of polymers which phase separated readily (e.g. polystyrene and PLLA) were the least sensitive to temperature changes. Process yield and size distribution show no clear trends with respect to air flow rate across the top of the reaction vessel. The efficiency of the process to produce DW microspheres increased and the process time decreased with increasing air flow across the surface of the encapsulation vessel.
journal_name
J Microencapsuljournal_title
Journal of microencapsulationauthors
Leach K,Noh K,Mathiowitz Edoi
10.1080/026520499289149subject
Has Abstractpub_date
1999-03-01 00:00:00pages
153-67issue
2eissn
0265-2048issn
1464-5246journal_volume
16pub_type
杂志文章abstract::In this study, we formulated a microparticulate melanoma cancer vaccine via the transdermal route. The vaccine was delivered using microneedle-based Dermaroller® which is available for cosmetic purposes. Unlike subcutaneous injections, administration using microneedles is painless and in general can increase the perme...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652048.2011.559287
更新日期:2011-01-01 00:00:00
abstract::The formation of microcapsules which contain rosemary oil, is herewith described. The process is based on two steps: (a) formation of oil-in-water emulsions, by using lecithin as emulsifier, thus imparting negative charges on the oil droplets; (b) addition of a cationic biopolymer, chitosan, in conditions that favor t...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652049709015332
更新日期:1997-03-01 00:00:00
abstract::Aim: A novel folated pluronic F127 (FA-F127) was synthesised, so as to modify liposomes with FA group on the surface, and evaluate the effects of FA-F127 modification on the properties of the modified liposomes.Methods: FA was linked to one end of pluronic F127, via the terminal OH group, to obtain FA-F127 and the str...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.1080/02652048.2020.1720030
更新日期:2020-05-01 00:00:00
abstract::The purpose of the present study was to provide further insights on the applicability of microencapsulation using emulsification method, to immobilise Clostridium acetobutylicum ATCC 824 spores, for biobutanol production. The encapsulated spores were revived using heat shock treatment and the fermentation efficiency o...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652048.2015.1017617
更新日期:2015-01-01 00:00:00
abstract::The blood-brain barrier (BBB) is the major problem for the treatment of central nervous system diseases. A previous study from our group showed that the brain-targeted chitosan nanoparticles-loaded with large peptide moieties can rapidly cross the barrier and provide neuroprotection. The present study aims to determin...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.1080/02652048.2017.1375039
更新日期:2017-11-01 00:00:00
abstract::Isoniazid was encapsulated into microspheres of alginate-chitosan by means of a complex coacervation method in an emulsion system. Since the encapsulation of isoniazid tends to be limited by its hydrophilic characteristics, this study proposes its microencapsulation by adsorption. The particles were prepared in three ...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:
更新日期:2003-03-01 00:00:00
abstract::The preparation of dipyridamole (DIP) alginate (alg) microspheres by different methods or the incorporation of tragacanth (trgh), pectin or Eudragit L-100 55 (Eud) in alg microsphere formulations did not provide a prolonged release of DIP at pH 1.2. Tabletted microsphere formulations containing alg, trgh, pectin, sodi...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.1080/026520499288906
更新日期:1999-07-01 00:00:00
abstract::Liposomes are known to be a potent adjuvant for a wide range of antigens, as well as appropriate antigen carriers for antibody generation response in vivo. In addition, liposomes are effective vehicles for peptides and proteins, thus enhancing their immunogenicity. Considering these properties of liposomes and the ant...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652048.2014.958203
更新日期:2015-01-01 00:00:00
abstract::This paper describes a novel approach to prepare and characterize calcium-shellac spheres as a carrier of a tooth whitening agent carbamide peroxide. Calcium-shellac spheres were prepared using an extrusion technique based on dropping aqueous ammonium shellac solution into calcium chloride solution. The effects of for...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.1080/02652040802049638
更新日期:2008-12-01 00:00:00
abstract:AIM:To develop a biocompatible cobalt ferrite (CF-NP) nanodrug formulation using oleic acid and poly (d,l-lactide-co-glycolic) acid (PLGA) for the delivery of docetaxel (DTX) specifically to breast cancer cells. METHODS:The CF-NP were synthesised by hydrothermal method and conjugated with DTX in a PLGA matrix and were...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.1080/02652048.2020.1842529
更新日期:2021-01-01 00:00:00
abstract::Captopril microcapsules were prepared using four different viscosity grades of ethyl cellulose (core: wall ratios 1:1, 1:2 and 1:3) by temperature induced coacervation from cyclohexane. In vitro dissolution studies in 0.1 M hydrochloric acid showed that the drug release was dependent on the core to wall ratio, the vis...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652049009028424
更新日期:1990-01-01 00:00:00
abstract::In this study, recombinant human interleukin-2 (rhIL-2) containing poly(lactic-co-glycolic acid) (PLGA) microparticles were prepared for pulmonary administration by modified w/o/w double emulsion solvent extraction method and the effects of various formulation parameters on the physicochemical properties of the microp...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652048.2011.599438
更新日期:2011-01-01 00:00:00
abstract::The effects of different loading procedures of magnetic nanoparticles (MNs) on the structure and physicochemical properties of cisplatin magnetic liposomes were investigated by X-ray diffraction, infrared spectroscopy, transmission electron microscopy, and fluorescence spectroscopy. 1, 2-Dipalmitoyl-sn-glycero-3-Phosp...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652048.2012.692397
更新日期:2012-01-01 00:00:00
abstract::The degradation of polybutylcyanoacrylate (PBC) and polyhexylcyanoacrylate (PHC) nanoparticles, together with their association with and toxicity towards isolated hepatocytes, were determined. Nanoparticles were not taken up by rat hepatocytes at a significant level. The LD50S of PBC and PHC nanoparticles towards hepa...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652048409049364
更新日期:1984-07-01 00:00:00
abstract::Indomethacin-loaded dietheylaminoethyl trisacryl microspheres (DEAE-MS), originally designed for therapeutic embolization, were encapsulated using two methods: coacervation and solvent evaporation/extraction. This encapsulation was achieved using a biocompatible polymer, the PLGA 50 : 50, and aimed to control the rele...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.1080/02652040701843388
更新日期:2008-03-01 00:00:00
abstract::Moisture curing type self-healing microcapsules become more attractive, while instability of active core material crippled the efficiency of self-healing behaviour. Polyurea (PU)/melamine formaldehyde (MF) double-layered self-healing microcapsules containing isophorone diisocyanate (IPDI) core with high and stable cor...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.1080/02652048.2016.1178352
更新日期:2016-06-01 00:00:00
abstract::The purpose of this study was to design and characterise an oral mucoadhesive micellar drug carrier. In this regard, a mucoadhesive hydrophobic cationic aminocellulose was easily synthesised under mild homogeneous conditions with high yield. The cellulose derivative resulted in strongly improved mucoadhesive propertie...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652048.2015.1046516
更新日期:2015-01-01 00:00:00
abstract::To improve poor water solubility of cyclosporine A (CsA), hydroxypropyl-beta-cyclodextrin (HPβCD) was incorporated into the nanoparticle formulation. Solid complexes of CsA with HPβCD in different ratios were prepared by the kneading method. CsA containing alone or in combination with HPβCD in poly-lactide-co-glycolid...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652048.2012.668961
更新日期:2012-01-01 00:00:00
abstract:CONTEXT:Quercetin (QUE) is a flavonoid with antioxidant/anti-inflammatory properties, poorly absorbed when orally administered. OBJECTIVES:To prepare chitosan/xanthan gum microparticles to increase QUE oral bioavailability and optimize its release in the colon. MATERIALS AND METHODS:Chitosan/xanthan gum hydrogel embe...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652048.2014.913726
更新日期:2014-01-01 00:00:00
abstract::The microencapsulation of drugs is gaining importance in many research activities. A common technique for preparing microcapsules is the solvent evaporation method which is simple but has a large number of reaction control parameters. This study reports the microcapsulation of allopurinol by the solvent evaporation me...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652049609026038
更新日期:1996-09-01 00:00:00
abstract::Polylactide (PLA) and polylactide-co-glycolide (PLGA) particles entrapping rotavirus (strain SA11) were formulated using a solvent evaporation technique. To minimize denaturation of viral antigen during the emulsification process, serum albumin was used as a stabilizer. Use of NaHCO(3) and sucrose during the primary e...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.1080/02652040802211709
更新日期:2009-03-01 00:00:00
abstract::In ophthalmic drug delivery, a major problem is retaining an adequate concentration of a therapeutic agent in the pre-corneal area. Polycarboxylic acid carriers such as polyacrylic acid and polyitaconic acid in sub-colloidal, nanoparticulate hydrogel form have a strong potential for sustained release of a drug in ocul...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.1080/02652040400008515
更新日期:2004-12-01 00:00:00
abstract::The present study is part of a larger project whose aim is to understand how the oyster Crassostrea gigas develops its aromas from a lipid precursor, the eicosapentaenoic acid (EPA), in glyceride form. The objective of this study is, therefore, to prepare an encapsulation process that will enable the bivalve to be sup...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:
更新日期:2003-01-01 00:00:00
abstract::Poly-D,L-lactide (PDLLA) and polylactide-co-glycolide (PLGA) microspheres containing thymopentin have been prepared by a water-in-oil-in-water-emulsion/solvent evaporation technique. The goal is to stabilize the active compound thymopentin, and to prolong its therapeutic activity, by embedding the drug in a polymeric ...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652049709051134
更新日期:1997-05-01 00:00:00
abstract::Gelatin/gum arabic (GA) microcapsules were prepared by a convenient one step complex coacervation, in which TiO2 nanoparticles modified by stearic acid (SA) and homodispersed in tetrachloroethylene (TCE) were encapsulated. The modified TiO2 was characterized by Fourier transform infrared spectroscopy (FT-IR), dynamic ...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.1080/02652040802127806
更新日期:2009-02-01 00:00:00
abstract::Multilamellar liposomes incorporating essential oil of Brazilian cherry (Eugenia uniflora L.) leaves were produced by dry film hydration. Gas chromatography demonstrated the compounds found in the essential oil were effectively incorporated in the aqueous dispersions of liposomes. Differential scanning calorimetry ana...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652040903367327
更新日期:2010-01-01 00:00:00
abstract::The objective of this study was to prepare a microparticulate drug delivery system being based on a new thiomer, namely a chitosan 2-iminothiolane conjugate (chitosan-TBA conjugate). Due to thiol groups being immobilized on chitosan, chitosan-TBA conjugate exhibits improved mucoadhesive and permeation enhancing proper...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.1080/02652040500162220
更新日期:2005-08-01 00:00:00
abstract::Bacampicillin hydrochloride has been microencapsulated to mask its very bitter taste. The objective of the study was to compare the in vitro release and bioavailability of bacampicillin hydrochloride from microcapsules coated with two principally different polymers: a water-insoluble polymer, ethylcellulose, and an ac...
journal_title:Journal of microencapsulation
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.3109/02652048509031556
更新日期:1985-04-01 00:00:00
abstract::The effect of lecithin and starch on viability of alginate encapsulated probiotics was determined at different temperatures. Probiotic organisms (1% v/v>10Log CFU ml(-1)) were encapsulated using alginate (2% w/v), gelatinized starches (2% w/v) and lecithin (0-4% w/v) and stored in sealed containers at 4, 23 and 37 deg...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652040902982183
更新日期:2010-01-01 00:00:00
abstract::The effect of process variables such as nozzle size, flow-rate of dispersed phase, inter-electrode distance, and presence of an acid acceptor and a thickening agent in the dispersed phase, on the production and size distribution of nylon 6-10 microcapsules prepared by interfacial polymerization in a high-voltage elect...
journal_title:Journal of microencapsulation
pub_type: 杂志文章
doi:10.3109/02652049509015288
更新日期:1995-03-01 00:00:00