{"id":5950,"date":"2026-10-19T09:48:13","date_gmt":"2026-10-19T09:48:13","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-lyfjafraedi-blanca-lorenzo-veiga\/"},"modified":"2026-10-19T09:48:13","modified_gmt":"2026-10-19T09:48:13","slug":"doktorsvorn-i-lyfjafraedi-blanca-lorenzo-veiga","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-lyfjafraedi-blanca-lorenzo-veiga\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed lyfjafr\u00e6\u00f0i – Blanca Lorenzo-Veiga"},"content":{"rendered":"
\n
\n

M\u00e1nudaginn 26. okt\u00f3ber ver Blanca Lorenzo-Veiga doktorsritger\u00f0 s\u00edna \u00ed lyfjafr\u00e6\u00f0i vi\u00f0 Lyfjafr\u00e6\u00f0ideild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0: S\u00fdkl\u00f3dextr\u00edn nan\u00f3agnir fyrir augnlyfjagj\u00f6f. Cyclodextrin nanostructures and ocular drug delivery.<\/strong><\/p>\n

V\u00f6rninni ver\u00f0ur streymt:<\/p>\n

Andm\u00e6lendur eru dr. Francisco Otero-Espinar, pr\u00f3fessor vi\u00f0 University of Santiago de Compostela, Sp\u00e1ni, og dr. Ana Paula Serro, d\u00f3sent vi\u00f0 University of Lisbon, Port\u00fagal.<\/p>\n

Umsj\u00f3narkennari og lei\u00f0beinandi var dr. H\u00e1kon Hrafn Sigur\u00f0sson, pr\u00f3fessor vi\u00f0 \u00a0H\u00e1sk\u00f3la \u00cdslands, og me\u00f0lei\u00f0beinandi var dr. \u00deorsteinn Loftsson, pr\u00f3fessor emeritus vi\u00f0 H\u00e1sk\u00f3la \u00cdslands. A\u00f0rir \u00ed doktorsnefnd voru Margr\u00e9t \u00deorsteinsd\u00f3ttir, pr\u00f3fessor vi\u00f0 Lyfjafr\u00e6\u00f0ideild, Einar Stef\u00e1nsson, pr\u00f3fessor vi\u00f0 L\u00e6knadeild, og Carmen \u00c1lvarez Lorenzo, pr\u00f3fessor vi\u00f0 University of Santiago de Compostela.<\/p>\n

El\u00edn Soff\u00eda \u00d3lafsd\u00f3ttir, pr\u00f3fessor og forseti Lyfjafr\u00e6\u00f0ideildar, stj\u00f3rnar ath\u00f6fninni sem fer eing\u00f6ngu fram \u00e1 Zoom og hefst kl. 09:00.<\/p>\n

\u00c1grip af ranns\u00f3kn<\/strong><\/p>\n

\u00der\u00f3un augnlyfja er mj\u00f6g krefjandi vegna einstakrar byggingar augans og hindrana sem eru \u00e1 fl\u00e6\u00f0i lyfja \u00ed gegnum himnur augans. L\u00edtil vatnsleysni margra lyfja og of stuttur vi\u00f0verut\u00edmi \u00feeirra \u00e1 yfirbor\u00f0i augans gerir \u00fer\u00f3un augnlyfjasamsetninga enn erfi\u00f0ari. Nokkar a\u00f0fer\u00f0ir hafa veri\u00f0 reyndar til a\u00f0 auka a\u00f0gengi lyfja inn \u00ed auga\u00f0. S\u00fdkl\u00f3dextr\u00edn nan\u00f3agnir eru \u00e1hugaver\u00f0 n\u00e1lgun \u00e1 \u00feessu vandam\u00e1li \u00fear sem s\u00fdkl\u00f3dextr\u00edn hafa mikla getu til a\u00f0 auka vatnsleysni fitus\u00e6kinna lyfja og hj\u00e1lpa \u00feeim a\u00f0 komast \u00ed gegnum l\u00edfr\u00e6nar himnur. S\u00fdkl\u00f3dextr\u00edn nan\u00f3agnir auka vi\u00f0verut\u00edma lyfja \u00e1 yfirbor\u00f0i augans og valda me\u00f0 \u00fev\u00ed auknu fr\u00e1sogi inn \u00ed auga\u00f0.<\/p>\n

Markmi\u00f0 \u00feessa verkefnis var a\u00f0 auka leysni lyfjanna Nepafenac og Natamycin me\u00f0 notkun s\u00fdkl\u00f3dextr\u00edn fl\u00e9tta og fj\u00f6lli\u00f0a sem mynda \u00f6rkjarna \u00ed lausn og auka fr\u00e1sog lyfjanna \u00ed gegnum helstu himnur augans.<\/p>\n

Nepafenac er b\u00f3lguey\u00f0andi lyf sem er \u00e1v\u00edsa\u00f0 gegn b\u00f3lgum og verkjum sem fylgja augasteinsa\u00f0ger\u00f0um. Lyfi\u00f0 er torleyst \u00ed vatni og kemst illa \u00ed gegnum himnur augans. Fl\u00e9ttumyndun lyfsins vi\u00f0 sex s\u00fdkl\u00f3dextr\u00edn \u00ed fj\u00f6lli\u00f0ulausnum var ranns\u00f6ku\u00f0 \u00e1samt \u00fev\u00ed a\u00f0 sko\u00f0a hvernig nan\u00f3agnir myndu\u00f0ust. Helstu ni\u00f0urst\u00f6\u00f0ur s\u00fdndu a\u00f0 HP\u03b2-CD j\u00f3k leysni lyfsins mest og \u03b3-CD \u00a0stu\u00f0la\u00f0i a\u00f0 mestri nan\u00f3agnamyndum. Fl\u00e9ttumyndum var ranns\u00f6ku\u00f0 me\u00f0 leysniferli \u00e1samt DSC, FT-IR og \u00b9H-NMR a\u00f0fer\u00f0um. S\u00fa fl\u00e9tta sem kom best \u00fat var samsett \u00far 15% (w\/v) \u03b3-CD og 8% (w\/v) HP\u03b2-CD. S\u00fa fl\u00e9tta var \u00fer\u00f3u\u00f0 \u00e1fram me\u00f0 mismunandi vatnsleysanlegum fj\u00f6lli\u00f0um. E\u00f0lislyfjafr\u00e6\u00f0ilegir eiginleikar fl\u00e9ttanna voru rannsaka\u00f0ir \u00e1samt \u00fev\u00ed a\u00f0 nota mismunandi a\u00f0fer\u00f0ir til a\u00f0 meta h\u00e6fni \u00feeirra til a\u00f0 koma lyfinu \u00ed gegnum himnur og vefi augans. Einnig voru l\u00edffr\u00e6\u00f0ilegar a\u00f0fer\u00f0ir nota\u00f0ar til a\u00f0 meta virkni, ertingu og eitrunar\u00e1hrif lyfjasamsetninganna. Lyfjasamsetningarnar voru bornar saman vi\u00f0 Nevanac\u00ae\u00a0 sem er skr\u00e1\u00f0 lyf \u00e1 marka\u00f0i og komu \u00fe\u00e6r mun betur \u00fat m.t.t. ofangreindra \u00fe\u00e1tta heldur en skr\u00e1\u00f0a lyfi\u00f0.<\/p>\n

Natamycin er nota\u00f0 vi\u00f0 sveppas\u00fdkingum \u00ed augum. Notkun \u00feess er \u00fe\u00f3 takm\u00f6rku\u00f0 vegna \u00feess hve torleyst lyfi\u00f0 er og a\u00f0gengi \u00feess \u00ed augum l\u00e9legt. Fj\u00f6lli\u00f0urnar Soluplus\u00ae og Pluronic\u00ae P103 voru nota\u00f0ar til a\u00f0 b\u00faa m\u00edsellur, blanda\u00f0ar m\u00edsellur og rotaxana \u00ed mismunandi lyfjasamsetningum me\u00f0 \u03b1-CD. E\u00f0lislyfjafr\u00e6\u00f0ilegir eiginleikar fj\u00f6lli\u00f0ukerfanna voru rannsaka\u00f0ir \u00e1samt \u00fev\u00ed a\u00f0 nota mismunandi a\u00f0fer\u00f0ir til a\u00f0 meta h\u00e6fni \u00feeirra til a\u00f0 koma lyfinu \u00ed gegnum himnur og vefi augans. Einnig voru l\u00edffr\u00e6\u00f0ilegar a\u00f0fer\u00f0ir nota\u00f0ar til a\u00f0 meta virkni, ertingu og eitrunar\u00e1hrif lyfjasamsetninganna. Soluplus m\u00edsellur reyndust best til a\u00f0 auka leysni lyfsins. Rotaxanar reyndust ekki hentugir til a\u00f0 auka fl\u00e6\u00f0i lyfsins inn \u00ed vefi augans samanbori\u00f0 vi\u00f0 m\u00edsellurnar.<\/p>\n

Samanteki\u00f0 \u00fe\u00e1 t\u00f3kst a\u00f0 \u00fer\u00f3a lyfjasamsetningar fyrir annars vegar Nepafenac og hins vegar Natamycin sem auka leysni lyfjanna, hafa hentuga eiginleika fyrir augnlyfjasamsetningar og valda ekki ertingu e\u00f0a eitrunar\u00e1hrifum \u00ed einf\u00f6ldum pr\u00f3funum.<\/p>\n

Abstract<\/strong><\/p>\n

Ocular drug delivery is very challenging due to the anatomical and physiological barriers of the eye. Poor aqueous solubility of many drugs and short retention time at ocular surfaces makes the formulation of topical dosage forms even more challenging. Several approaches have been reported to enhance drug bioavailability at the ocular tissues. Cyclodextrin-based nanocarriers have been selected due to their well-known capability of cyclodextrins to enhance the solubility of lipophilic drugs and its permeability through biological membranes. They can also prolong the retention time of ophthalmic formulations on the ocular surface and, as a consequence, increase their bioavailability.<\/p>\n

The aim of this project was to apply cyclodextrin technology and cyclodextrin-amphiphilic copolymers to enhance the aqueous solubility of two poorly soluble drugs, Nepafenac and Natamycin, as well as their corneal or scleral accumulation.<\/p>\n

Nepafenac is a non-steroidal anti-inflammatory drug (NSAID) prescribed for the treatment of pain and inflammation that usually occurred after cataract surgery. Nepafenac has low water solubility and ocular permeability. The complexation of nepafenac with six CDs and various water-soluble polymers was investigated. Results showed that HP\u03b2-CD showed the highest solubilizing capacity, while \u03b3-CD led to the highest aggregate formation. Complex formation was investigated and supported by phase solubility analysis, DSC, FT-IR and \u00b9H-NMR. The optimized complex, which contained 15% (w\/v) \u03b3-CD and 8% (w\/v) HP\u03b2-CD, was selected for additional studies. Nine formulations containing nepafenac\/\u03b3-CD\/HP\u03b2-CD complexes and various water-soluble polymers were prepared. Physicochemical and rheological characterization, mucoadhesive capacity, ocular tolerance, diffusion studies, corneal and scleral permeability, and anti-inflammatory activity of these formulations were investigated and compared to the marketed nepafenac suspension, Nevanac\u00ae 3 mg\/mL. The formulations displayed zeta potential from \u20136 to \u201327 mV, microparticle size in the range of 340-5950 nm, neutral pH and high sclera permeation. Moreover, they were found to be non-toxic and non-irritant. Compared to Nevanac\u00ae, formulations containing poly(vinyl)-alcohol (PVA), methylcellulose (MC) and carboxymethyl cellulose (CMC) presented the best results in relation to sclera accumulation and anti-inflammatory activity.<\/p>\n

Natamycin is approved for the treatment of fungal keratitis but its use is restricted due to its low water solubility and low ocular penetration. Soluplus\u00ae and Pluronic\u00ae P103 were selected as surfactants to prepare single and mixed micelles and poly(pseudo)rotaxanes for Natamycin encapsulation. Soluplus, Pluronic P103 and a mixture of Soluplus\/ Pluronic in ratio 4:1 dispersions were prepared with and without 10% \u03b1-CD in 0.9% sodium chloride or buffer pH 6.4. They were investigated in relation to their solubility, particle size, zeta potential, pH, rheological properties, diffusion studies, ocular irritancy, and ex vivo cornea and sclera permeation. All formulations revealed zeta potentials close to zero while differences were found with respect to their size. Soluplus micelles and mixed micelles revealed larger sizes (range 90-150 nm) followed by Pluronic P103 micelles. Soluplus micelles led to the highest Natamicyn solubility, followed by Pluronic P103 and their mixed micelles. All formulations were found cytocompatible on murine fibroblasts and did not display irritation. Although Soluplus nanomicelles and poly(pseudo)rotaxanes showed in situ gel behavior at 35 \u00baC and the highest solubilizing capacity, Pluronic and Soluplus\u00a0 poly(pseudo)rotaxanes led to the lowest diffusion rate and corneal and sclera permeation. Moreover, poly(pseudo)rotaxanes of mixed micelles showed intermediate diffusion release and permeability through cornea and sclera comparing to only Soluplus and Pluronic poly(pseudo)rotaxanes.<\/p>\n

To conclude, we would like to point out that both optimized Nepafenac formulation and Natamycin-based mixed poly(pseudo)rotaxanes may represent a new approach for topical instillation of drugs to the posterior segment of the eye.<\/p>\n

Um doktorsefni\u00f0<\/strong><\/p>\n

Blanca Lorenzo-Veiga f\u00e6ddist \u00ed Vigo \u00e1 Sp\u00e1ni 31. desember 1990. H\u00fan \u00fatskrifa\u00f0ist me\u00f0 MS-pr\u00f3f \u200b\u200b\u00ed lyfjafr\u00e6\u00f0i fr\u00e1 H\u00e1sk\u00f3lanum \u00ed Santiago de Compostela \u00e1 Sp\u00e1ni \u00e1ri\u00f0 2014 og a\u00f0ra meistaragr\u00e1\u00f0u \u00ed ranns\u00f3knum og \u00fer\u00f3un \u00ed lyfjafr\u00e6\u00f0i fr\u00e1 sama h\u00e1sk\u00f3la \u00e1ri\u00f0 2016. H\u00fan starfa\u00f0i sem lyfjafr\u00e6\u00f0ingur fr\u00e1 \u00e1rinu 2014 \u00fear til h\u00fan h\u00f3f doktorsn\u00e1m sitt vi\u00f0 Lyfjafr\u00e6\u00f0ideild H\u00e1sk\u00f3la \u00cdslands hausti\u00f0 2016. H\u00fan hlaut Erasmus-styrk \u00ed doktorsn\u00e1mi s\u00ednu \u00e1ri\u00f0 2018 og dvaldi eitt \u00e1r \u00e1 ranns\u00f3knarstofu hj\u00e1 pr\u00f3fessor Carmen Alvarez-Lorenzo vi\u00f0 H\u00e1sk\u00f3lann \u00ed Santiago de\u00a0 Compostela.<\/p>\n<\/div><\/div>","protected":false},"featured_media":1083,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2020-10-26T09:00:00+00:00","_phd_date_end":"2020-10-26T12:00:00+00:00","_phd_location":"","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"S\u00fdkl\u00f3dextr\u00edn nan\u00f3agnir fyrir augnlyfjagj\u00f6f. Cyclodextrin nanostructures and ocular drug delivery","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_lyfjafraedi_blanca_lorenzo_veiga","_phd_source_node_id":"370207","_phd_source_type":"vidburdir","_phd_member_id":90,"footnotes":""},"phd_school":[60,64],"phd_discipline":[66],"class_list":["post-5950","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-heilbrigdisvisindasvid","phd_school-lyfjafraedideild","phd_discipline-phd-i-lyfjafraedi"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/5950","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence"}],"about":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/types\/phd_defence"}],"version-history":[{"count":0,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/5950\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/1083"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=5950"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=5950"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=5950"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}