Peribulbar poloxamer for ocular drug delivery.
OBJECTIVE
The use of biopolymers in peribulbar injection for controlled drug delivery provides alternative options to eyedrops and intravitreal or surgical methods. Polymerizable biopolymers are especially likely to have a role because of their particular properties. In liquid form, they can be easily injected into the target site and, after polymerization, they provide a prolonged and controlled release of the drug. This study was undertaken to demonstrate the suitability of a thermopolymerizable biopolymer poloxamer (Lutrol F127) for peribulbar injections and controlled drug release.


METHODS
The toxicity of injected poloxamer compounds was evaluated by visual inspection and histological and immunohistochemical tissue evaluation. The release of marker substances such as 5(6)-carboxyfluorescein (376 Da) or fluorescein isothiocyanate-dextran (FITC-dextran) (4-40 kDa) from poloxamer was used to simulate drug release and penetration into the eye using in vivo fluorometry.


RESULTS
According to our clinical and pathological analyses, poloxamer was well tolerated in peribulbar injections and did not cause acute toxicity at the site of injection. The marker compounds were released from the site of injection during the first 24 hours.


CONCLUSIONS
Although poloxamer appears to be suitable for peribulbar injections, a more prolonged period of dissolution is desirable for clinical purposes.
Vehanen
Katja
K
Department of Ophthalmology, University of Kuopio, Kuopio, Finland. katja.vehanen@uku.fi
Hornof
Margit
M
Urtti
Arto
A
Uusitalo
Hannu
H
D000042:Absorption; D000818:Animals; D000867:Anterior Chamber / Q000378:metabolism; D003911:Dextrans / Q000008:administration & dosage / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000009:adverse effects; D005123:Eye; D016650:Fluorescein-5-isothiocyanate / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D005452:Fluoresceins / Q000008:administration & dosage / Q000493:pharmacokinetics; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000008:administration & dosage / Q000493:pharmacokinetics; D007150:Immunohistochemistry; D007267:Injections; D009799:Ocular Physiological Phenomena; D020442:Poloxamer / Q000008:administration & dosage / Q000009:adverse effects; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014822:Vitreous Body / Q000378:metabolism
D003911:Dextrans; D005452:Fluoresceins; D005456:Fluorescent Dyes; C015219:fluorescein isothiocyanate dextran; D020442:Poloxamer; C024098:6-carboxyfluorescein; D016650:Fluorescein-5-isothiocyanate