ISSN:0007-1641    

DOI:10.1002/pi.4980150402

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractSoluble synthetic polymers have potential as targetable drug delivery and release agents. Copolymers of 2‐hydroxypropylmethacrylamide with oligopeptide side‐chains have been used to demonstrate the attachment of drug analogues by covalent linkages susceptible to hydrolysis by lysosomal enzymes but stable in plasma. Targeting of polymers to particular sites has been illustrated by making use of the substrate specificity of adsorptive pinocyto

ISSN:0007-1641    

DOI:10.1002/pi.4980150403

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThe use of polymeric microspheres for the targeting of drugs to specific sites in the body is discussed in terms of the physico‐chemical properties that influence the fate and deposition of colloidal particles following intravenous administration. These include particle size, surface charge and surface hydrophobicity. Adsorbed surface coatings and adsorbed blood components also play a significant role in determining the site and extent of deposition. Drug targeting via the intravenous route can be achieved in certain instances. However, following administration the major site of particle deposition for small particles is the liver. The use of monoclonal antibodies as a coating agent to increase site specificity is also considere

ISSN:0007-1641    

DOI:10.1002/pi.4980150404

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThe release of the alkaloid ergotamine from thin discs of poly(2‐hydroxyethyl methacrylate) [PHEMA] into an aqueous buffered medium has been effected under sink conditions and monitored by fluorescence spectroscopy. The process was found to be diffusion controlled, the fraction of available drug released being linear in (time)1/2during the initial stages. The influences of disc thickness, drug load and temperature were investigated and yielded 2.0 (± 1.0) × 10−13m2s−1for the diffusion coefficient of ergotamine through the swollen gel at 310K and a value of 69 ± 5 kJ mol−1for the activation energy of diffusion. For the uptake of aqueous buffer alone into PHEMA the corresponding values wereca100 times greater and three times smaller re

ISSN:0007-1641    

DOI:10.1002/pi.4980150405

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractMany new polymeric controlled release drugs delivery systems are currently being marketed. The cornerstone for the development of these new drug presentations isin vitrorelease testing. This paper outlines the design conditions for such release systems, and factors such as drug solubility, solution diffusivitiy and hydrodynamics, as well asin vitro‐in vivocorrelations are discussed. The two main approaches toin vitrorelease system design are then outlined; the closed rotational systems and the open flow system

ISSN:0007-1641    

DOI:10.1002/pi.4980150406

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThe use of naturally‐occurring polymers, and in particular, kraft lignin, for controlled release pesticide formulations is reviewed. A matrix of kraft lignin containing polar pesticides can be prepared in granular form and the release rates of the active ingredient from this formulation are described. Successful applications of this type of formulation include herbicides for weed control in conifer plantation and insecticides in tropical flooded ric

ISSN:0007-1641    

DOI:10.1002/pi.4980150407

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractLiquid‐state radiation‐induced and electroinitiated polymerisations of epoxycyclohexane (ECH) have been investigated. The effect of temperature on the electroinitiated polymerisation rate was also studied. The decrease in monomer concentration during polymerisation was followed by gas chromatographic analysis of electrolysis solutions. The i.r. spectra of the polymers suggested polyether structure. N.m.r. spectra of products indicate that the polymerisation of ECH propagates through the opening of the epoxy rings. Poly(epoxycyclohexane) obtained by both methods are amorphous according to X‐ray ana

ISSN:0007-1641    

DOI:10.1002/pi.4980150408

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThe automation of a torsional braid analyser by interfacing with an Apple II microcomputer is described. The use of an analogue to digital convertor is discussed together with appropriate mathematical procedures for carrying out the subsequent on‐line data processing. Finally, the advantages of this automated system for obtaining thermomechanical spectra of polymeric materials, as compared with the previous method of data collection and analysis, are discusse

ISSN:0007-1641    

DOI:10.1002/pi.4980150409

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractLiquid state radiation‐induced and electroinitiated cationic polymerisation of 1,2‐epoxy‐4‐epoxyethylcyclohexane (EECH) have been investigated. Soluble and cross‐linked polymers were obtained during the radiation‐induced polymerisation of EECH, depending upon the radiation dose. Electroinitiated polymerisation of the monomer yielded cross‐linked polymers on the surface of the anode. The expected polyether structure was observed for i.r. data. The polymerisation propagates via opening of the epoxy rings as indicated by n.m.r. spectra. X‐Ray analyses showed that the products obtained by both method

ISSN:0007-1641    

DOI:10.1002/pi.4980150410

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractSpectroscopic (i.r., u.v.) studies of undoped polystyrene and that doped with Acrylic Acid films (30μ thick), prepared by isothermal immersion technique, have been reported. It is found that in the case of i.r. spectra an additional absorption peak appears near 1420cm−1, whereas those present near 1300 and 980cm−1, as shoulders in the undoped sample, appear as sharp peaks in the doped samples. In the region 3300–2500cm−1a broadening appears in the doped films which increases with the dopant concentration. In the case of u.v. spectra, out of four absorption regions present in the undoped films two bands merge and only three appear in the doped ones. The u.v. absoption increases with the dopant concentration. These results have been explained on the basis of a charge transfer complex formation due to the interaction between the dopant and the polyme

ISSN:0007-1641    

DOI:10.1002/pi.4980150411

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY