title: Precorneal residence time in humans of sodium hyaluronate as measured by gamma scintigraphy.
abstract: The aim of the present study was to quantify in man the distribution and clearance of two aqueous sodium hyaluronate (SH) solutions of 0.125% and 0.250% after the administration of 25 microliters onto the cornea. Isotonic phosphate buffer (PB) was used as a reference instillation. No systemic or local medication was given to the seven 18- to 30-year-old, healthy male volunteers. A detailed evaluation of the anterior segment of the eye, as well as a Schirmer test and a break-up time measurement, yielded results within the normal range. The clearance of 0.125% and 0.250% SH solutions radiolabelled with sodium pertechnetate Tc-99m was measured by gamma scintigraphy and compared with that of a PB solution tagged with the same radiolabel. There was no statistically significant difference between the quantities of 0.125% SH and PB solutions remaining in the precorneal space at 20 min (paired t-test, P = 0.78, n = 7). However, in comparing the 0.250% SH with the PB solution, we observed a statistically significant difference (P = 0.01, n = 7) in the amount remaining in the precorneal space after the same interval. Actually, 53% of the radiolabelled 0.250% SH solution remained on the cornea as compared with 30% for the 0.125% SH solution and 18.3% for the PB solution. These results suggest that an SH solution of 0.250% might have a prolonged residence time on the precorneal surface, and that SH could therefore be used as an additive in various drug-release systems for the eye.
authors.affiliation: Department of Pharmaceutical Technology, University of Geneva, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Gurny
authors.forename: J E
authors.initials: JE
authors.lastname: Ryser
authors.forename: C
authors.initials: C
authors.lastname: Tabatabay
authors.forename: M
authors.initials: M
authors.lastname: Martenet
authors.forename: P
authors.initials: P
authors.lastname: Edman
authors.forename: O
authors.initials: O
authors.lastname: Camber
mesh_terms: D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000869:Anterior Eye Segment / Q000000981:diagnostic imaging / Q000378:metabolism; D003315:Cornea / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008297:Male; D014677:Pharmaceutical Vehicles / Q000493:pharmacokinetics; D011877:Radionuclide Imaging; D013670:Sodium Pertechnetate Tc 99m; D013666:Tears / Q000378:metabolism
chemical_list: D014677:Pharmaceutical Vehicles; D006820:Hyaluronic Acid; D013670:Sodium Pertechnetate Tc 99m