Timolol gel forming solution

Other quaternary ammonium germicides, ben-zethonium chloride and benzalkonium bromide, have been used in several ophthalmic solutions. While these have the advantage of not being a chemical mixture, they do not possess the bactericidal effectiveness of benzalkonium chloride and are subject to the same incompatibility limitations. In addition, the maximum concentration for benzethonium chloride is 0.01%. Several new products that form gels in the eye, like Timolol Gel Forming Solution and Timoptic-XE, employ another quaternary preservative, BDAB, in the formulation. 

Shedden, A. H., Laurence, J., Barrish, A., and Olah, T. V. (2001), Plasma timolol concentrations of timolol maleate Timolol gel-forming solution (TIMOPTIC-XE) once daily versus timolol maleate ophthalmic solution twice daily, Doc. Ophthalmol., 103(1), 73-79. 

Plager DA, Whitson JT, Netland PA, Vijaya L, Sathyan P, Sood D, Krishnadas SR, Robin AL, Gross RD, Scheib SA, Scott H, Dickerson JE. BETOPTIC S Pediatric Study Group. Betaxolol hydrochloride ophthalmic suspension 0.25% and timolol gel-forming solution 0.25% and 0.5% in pediatric glaucoma a randomized clinical trial J AAPOS 2009 13(4) 384-90. 

Topical P-blockers are typically administered twice daily. A gel-forming solution of timolol (Timoptic-XE) can be administered once daily. Tachyphylaxis may occur in 20% to 50% of patients on monotherapy with a P-blocker, resulting in the need for a different agent or combination therapy. Patients on concurrent systemic P-blockers may experience less IOP reduction than patients only on topical P-blockers.10,38... 

Shedden, A., Laurence, I, and Tipping, R. (2001), Efficacy and tolerability of timolol maleate ophthalmic gel-forming solution versus timolol ophthalmic solution in adults with open-angle glaucoma or ocular hypertension A six-month, double-masked, multicenter study, Clin. Then, 23(3), 440 150. 

Schenker, H. I., and Silver, L. H. (2000), Long-term intraocular pressure-lowering efficacy and safety of timolol maleate gel-forming solution 0.5% compared with timoptic XE 0.5% in a 12-month study, Am. J. Ophthalmol., 130(2), 145-150. 

Comparative studies In 105 children who were treated with either betaxolol hydrochloride ophthalmic suspension 0.25% or timolol maleate ophthalmic gel-forming solution 0.25% and 0.5% after randomization, adverse events were mostly non-seri-ous and mild to moderate in intensity [26 ]. No patient stopped treatment because of adverse events, which were hyperemia of the eye, discomfort, irritation of the eye, discharge from the eye, lid margin crusting, pruritus of the eye, a sticky sensation, bradycardia, and hypotension. 

Shibuya,T., Kashiwagi, K., and Tsukahara, S. (2003), Comparison of efficacy and tolerability between two gel-forming timolol maleate ophthalmic solutions in patients with glaucoma or ocular hypertension, Ophthalmologica, 217(1), 31-38. 

A heteropolysaccharide (xanthan gmn) vehicle also prodnces longer ocular surface contact time and has been incorporated into a once-daily timolol gel formulation (Falcon gel-forming). Twenty-one minntes after instillation, 12% of a reference solution, 25% of the xanthan gum solution, and 39% of Gelrite solution remain on the ocnlar snrface (see Figure 2-8). 

Systemic effects are the most important adverse effects of / -blockers. Drug absorbed systematically may produce decreased heart rate, reduced blood pressure, negative inotropic effects, conduction defects, bronchospasm, central nervous system effects, and alteration of serum lipids, and may block the symptoms of hypoglycemia. The -specific agents betaxolol and possibly carteolol (due to ISA) are less likely to produce the systemic adverse effects caused by / -adrenergic blockade, such as the cardiac effects and bronchospasm, but a real risk still exists. The use of timolol as a gel-forming liquid or betaxolol as a suspension allows for administration of less drug per day, and therefore reduces the chance for systemic adverse effects compared with the aqueous solutions. 

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