Plasma timolol concentrations of timolol maleate: timolol gel-forming solution (TIMOPTIC-XE®) once daily versus timolol maleate ophthalmic solution twice daily
Rent the article at a discountRent now
* Final gross prices may vary according to local VAT.Get Access
Purpose: The objective of this study was to compare plasma concentrations of timolol following multiple dosing of the therapeutic regimens of timolol maleate ophthalmic gel-forming solution (Timolol GS; TIMOPTIC-XE®) and timolol maleate ophthalmic solution. Timolol maleate ophthalmic gel-forming solution is also referred to as Timolol GS, i.e. gel-forming solution. Methods: This was a masked observer, two-period crossover study in six normal male subjects randomized to receive either Timolol GS, 0.5% (TIMOPTIC-XE,) once daily (0530 hours) or timolol maleate ophthalmic solution (0.5% TIMOPTIC®) twice daily (0530 and 1730 hours) for 8 days, in both eyes. On Day 8, a blood sample was obtained prior to treatment, as well as 1, 2, 4, 8, 10, 12, 13, 14, 16, and 24 hours following the morning instillation. After a 7-day inter-period washout interval, subjects received the opposite treatment. Results: Timolol GS (TIMOPTIC-XE): Plasma concentrations of timolol rarely exceeded 0.375 ng/ml (the lower limit of assay quantification). For all subjects, peak plasma concentrations of timolol averaged <0.3 ng/ml within 4 hours after the last dose. The highest single observation was 0.49 ng/ml in one subject (at hour 2). Timolol solution: For all subjects, peak plasma concentrations of timolol averaged about 0.5 ng/ml and 0.3 ng/ml within 4 hours following the first and second dose, respectively, on Day 8. The highest single observation was 0.95 ng/ml in one subject (at hour 2). Conclusions: The data suggest that there is less systemic exposure to timolol following once-daily therapy with Timolol GS 0.5% compared with twice daily therapy with timolol maleate ophthalmic solution 0.5%.
- Greaves JL, Wilson CG, Rozier A, Grove J, Plazonnet B. Scintigraphic assessment of an ophthalmic gelling vehicle in man and rabbit. Curr Eye Res 1990; 415-20.
- Shedden AH. Timolol maleate in gel-forming solution: a novel formulation of timolol maleate.Chibret Intl J Ophthalmol 1994;10:332-6.
- Laurence J, Holder D, Vogel R, Gross RL, Haik BG, Karp DW, Koby MM, Zimmerman TJ. A double-masked, placebo-controlled evaluation of timolol in gel vehicle.J Glaucoma 1993;2:177-82.
- Vogel R, Shedden A, Laurence JK, Neafus R and the Study Group for Timolol-in Gelrite Pharmacology. The ocular hypotensive effect of once daily administration of timolol-in-Gelrite (TG) vs. timolol solution (TS).Invest Ophthalmol Vis Sci 1991;32:946.
- Alvan G, Calissendorff B, Seideman P, Widmark K, Widmark G. Absorption of ocular timolol.Clin Pharmacokinet1980;5:95-100.
- Passo MS, Palmer EA, van Buskirk EM.Plasma timolol in glaucoma patients.Ophthalmology 1984;91:136-3.
- Zimmerman TJ, Kooner KS, Kandarakis AS, Ziegler LP. Improving the therapeutic index of topically applied ocular drugs.Arch Ophthalmol1984;102:551-3.
- Plasma timolol concentrations of timolol maleate: timolol gel-forming solution (TIMOPTIC-XE®) once daily versus timolol maleate ophthalmic solution twice daily
Volume 103, Issue 1 , pp 73-79
- Cover Date
- Print ISSN
- Online ISSN
- Kluwer Academic Publishers
- Additional Links
- gellan gum
- plasma levels
- Industry Sectors