{"id":6300,"date":"2026-10-19T09:48:44","date_gmt":"2026-10-19T09:48:44","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-lyfjafraedi-suppakan-sripetch\/"},"modified":"2026-10-19T09:48:44","modified_gmt":"2026-10-19T09:48:44","slug":"doktorsvorn-i-lyfjafraedi-suppakan-sripetch","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-lyfjafraedi-suppakan-sripetch\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed lyfjafr\u00e6\u00f0i – Suppakan Sripetch"},"content":{"rendered":"
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Fimmtudaginn 29. september ver Suppakan Sripetch doktorsritger\u00f0 s\u00edna \u00ed lyfjafr\u00e6\u00f0i vi\u00f0 Lyfjafr\u00e6\u00f0ideild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0: Augnlyfjaferjur bygg\u00f0ar \u00e1 \u03b3-s\u00fdkl\u00f3dextr\u00edni. \u03b3-Cyclodextrin-based carrier in ocular drug delivery.<\/p>\n

Andm\u00e6lendur eru dr. Nunzio Denora, pr\u00f3fessor vi\u00f0 H\u00e1sk\u00f3lann \u00ed Bari Aldo Moro, \u00cdtal\u00edu, og Dr. Ana Paula Serro, lektor vi\u00f0 H\u00e1sk\u00f3lann \u00ed Lissabon, Port\u00fagal.<\/p>\n

Umsj\u00f3narkennari og lei\u00f0beinandi var \u00deorsteinn Loftsson, pr\u00f3fessor emer\u00edtus. Auk hans s\u00e1tu \u00ed doktorsnefnd Einar Stef\u00e1nsson, pr\u00f3fessor emer\u00edtus, H\u00e1kon Hrafn Sigur\u00f0sson, pr\u00f3fessor, Phatsawee Jansook, MS Pharm. PhD, og Sunna J\u00f3hannsd\u00f3ttir, PhD (l\u00e1tin).<\/p>\n

El\u00edn Soff\u00eda \u00d3lafsd\u00f3ttir, pr\u00f3fessor og deildarforseti Lyfjafr\u00e6\u00f0ideildar, stj\u00f3rnar ath\u00f6fninni sem fer fram \u00ed H\u00e1t\u00ed\u00f0asal H\u00e1sk\u00f3la \u00cdslands og hefst kl. 13.30.<\/p>\n

V\u00f6rninni ver\u00f0ur streymt:\u00a0<\/p>\n

https:\/\/livestream.com\/hi\/doktorsvornsuppakansripetch<\/a><\/p>\n

\u00c1grip<\/strong><\/p>\n

Mj\u00f6g erfitt er a\u00f0 koma lyfjum fr\u00e1 yfirbor\u00f0i augans til sj\u00f3nhimnunnar og \u00fev\u00ed felst lyfjame\u00f0h\u00f6ndlun sj\u00fakd\u00f3ma \u00ed sj\u00f3nhimnu n\u00fa oftast \u00ed innsp\u00fdtingu lyfja inn \u00ed auga\u00f0, en sj\u00fakd\u00f3mar \u00ed sj\u00f3nhimnu eru ein helsta \u00e1st\u00e6\u00f0a blindu. Doktorsverkefni\u00f0 fjallar um hvernig h\u00e6gt er a\u00f0 auka fr\u00e1sog lyfja fr\u00e1 yfirbor\u00f0inu til bakhluta augans me\u00f0 lyfjaferjum bygg\u00f0um \u00e1 \u03b3-s\u00fdkl\u00f3dextr\u00edni. Lyfjaferjurnar auka b\u00e6\u00f0i vatnsleysanleika og fr\u00e1sog fitus\u00e6kinna lyfja inn \u00ed auga\u00f0. \u03b3-S\u00fdkl\u00f3dextr\u00edn er hringlaga f\u00e1sykrungur sem myndar vatnsleysanlegar fl\u00e9ttur me\u00f0 m\u00f6rgum fitus\u00e6knum lyfjum \u00e1n \u00feess a\u00f0 breyta efnafr\u00e6\u00f0ilegri byggingu lyfjanna. Fl\u00e9tturnar h\u00f3pa sig saman til a\u00f0 mynda vatnsleysanlegar nan\u00f3agnir og m\u00edkr\u00f3agnir sem hafa takmarka\u00f0an leysanleika \u00ed vatni. \u00dar m\u00edkr\u00f3\u00f6gnunum voru \u00fatb\u00fanir augndropar sem juku fr\u00e1sog lyfja fr\u00e1 yfirbor\u00f0i augans til sj\u00f3nhimnunnar. \u00ddmsum ranns\u00f3knara\u00f0fer\u00f0um var beitt \u00ed verkefninu til a\u00f0 rannsaka myndun \u00e1 fl\u00e9ttum lyfja og s\u00fdkl\u00f3dextr\u00edna, hvernig s\u00fdkl\u00f3dextr\u00edn auka fr\u00e1sog lyfja \u00ed gegnum \u00feekjuvef og hvernig ens\u00edm \u00ed t\u00e1rav\u00f6kva brj\u00f3ta \u03b3-s\u00fdkl\u00f3dextr\u00edn ni\u00f0ur \u00ed malt\u00f3sa og gl\u00fak\u00f3sa eftir a\u00f0 fl\u00e9ttan leysist upp \u00ed t\u00e1rav\u00f6kvanum. Lyfin sem notu\u00f0 voru vi\u00f0 ranns\u00f3knirnar voru d\u00f3v\u00edt\u00edn\u00edb og dexametas\u00f3n, en b\u00e6\u00f0i lyfin eru torleysanleg \u00ed vatni en mynda vatnsleysanlegar fl\u00e9ttur me\u00f0 \u03b3-s\u00fdkl\u00f3dextr\u00edni.<\/p>\n

English abstract<\/strong><\/p>\n

Topical drug delivery to the eye especially posterior segment has been a challenge for formulation scientists due to low bioavailability in ocular tissues. Recent reports of gCD in topical delivery of corticosteroid to the back of eyes have drawn great attention of the researchers to explore into the foundation of gCD drug carrier and to seek feasibility of incorporation of new drug candidate in gCD-based carrier platform for eye diseases. The aims of this study were to improve aqueous solubility of dovitinib free base using gCD and\/or counterions such as hydrochloric, phosphoric, lactic, gluconic, and maleic acid; to examine physicochemical properties of the drug in the presence of gCD and other pharmaceutical excipients; to determine the effect of gCD on drug permeation; and to investigate the factors affecting drug permeation through lipophilic membrane and drug release from gCD-based carrier.<\/p>\n

Solubility studies and optimization showed a surprisingly synergistic effect of the solubilization of gCD and some counterions (e.g., lactic, phosphoric, and maleic acid) on dovitinib aqueous solubility. The solubility studies at high gCD concentration with the counterions like lactic and phosphoric acid provided spontaneous suspensions which contained self-assembled microparticles of dovitinib\/gCD complexes. Stability studies also showed that gCD stabilized dovitinib at relatively low pH. The stabilizing effect of gCD was more noticeable than the buffer effect. The lipophilicity studies indicated that the acidic counterions could affect the log10 of distribution coefficient (log D) of the ionized dovitinib but had a negligible impact on the log D of the unionized drug. In addition, the drug permeation studies through the artificial lipophilic membrane were performed to investigate the gCD effect on permeation of dexamethasone and the impact of formulation factor on dovitinib permeation. The results of dexamethasone permeation revealed that the highest permeation was obtained when both the thermodynamic activity of the drug and the soluble drug concentration were at maximum. However, the results from dovitinib permeation showed different phenomenon. The dovitinib flux and apparent permeability coefficient (Papp) decreased when the self-assembled nanoparticles existed. The effect of a-amylase enzyme, which has been found in tear fluid, on dexamethasone release from gCD-based carrier under mimic tear pH and ocular surface temperature showed unexpected additive effect of media dilution and a-amylase catalysis on the drug release.<\/p>\n

To conclude, gCD showed functional flexibility as an excipient depending upon its concentration and the presence of additives. It could both solubilize and stabilize the lipophilic drug of interest, dovitinib through forming complex and self-assembled gCD particles. gCD-based carrier can either enhance or hamper the drug permeation, but the effect can be optimized. Furthermore, drug release can be enhanced when a-amylase is present in diluted gCD solution. These findings suggest that gCD can be used as a drug carrier for lipophilic drug in topical delivery to the eyes.<\/p>\n

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

Suppakan Sripetch f\u00e6ddist \u00ed Ta\u00edlandi \u00feann 15. ma\u00ed 1981. \u00c1ri\u00f0 2004 \u00fatskrifa\u00f0ist h\u00fan me\u00f0 BS-gr\u00e1\u00f0u \u00ed lyfjafr\u00e6\u00f0i fr\u00e1 Chulalongkorn-h\u00e1sk\u00f3lanum \u00ed Ta\u00edlandi og MS \u00ed lyfjafr\u00e6\u00f0i fr\u00e1 sama h\u00e1sk\u00f3la \u00e1ri\u00f0 2010. \u00c1 \u00e1runum 2004-2006 og 2009-2018 starfa\u00f0i h\u00fan sem lyfjafr\u00e6\u00f0ingur \u00ed L\u00fd\u00f0heilsur\u00e1\u00f0uneyti Ta\u00edlands (Ministry of Public Health, Department of Medical Science). H\u00fan h\u00f3f doktorsn\u00e1m vi\u00f0 H\u00e1sk\u00f3la \u00cdslands \u00e1ri\u00f0 2018 samhli\u00f0a ranns\u00f3knum vi\u00f0 Oculis \u00e1 \u00cdslandi. Verkefni hennar er hluti af Oculis-verkefni um notkun \u03b3-s\u00fdkl\u00f3dextr\u00edns \u00ed augnlyfjum. Verkefni\u00f0 er styrkt af Oculis ehf.<\/p>\n<\/div><\/div>","protected":false},"featured_media":5257,"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":"2022-09-29T13:30:00+00:00","_phd_date_end":"2022-09-29T16:30:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0asalur","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Augnlyfjaferjur bygg\u00f0ar \u00e1 \u03b3-s\u00fdkl\u00f3dextr\u00edni. \u03b3-Cyclodextrin-based carrier in ocular drug delivery","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_lyfjafraedi_suppakan_sripetch","_phd_source_node_id":"389987","_phd_source_type":"vidburdir","_phd_member_id":832,"footnotes":""},"phd_school":[60,64],"phd_discipline":[66],"class_list":["post-6300","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\/6300","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\/6300\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/5257"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6300"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6300"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6300"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}