Ophthalmic gels

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. 

Sultana, Y., Aqil, M., and Ali, A. (2006), Ion-activated, Gelrite-based in situ ophthalmic gels of pefloxacin mesylate Comparison with conventional eye drops, Drug Deliv., 13(3), 215-219. 

Siatkowski RM, Cotter S, Miller JM, et al. Safety and efficacy of 2% pirenzepine ophthalmic gel in children with myopia a 1-year, multicenter, double-masked, placebo-controUed parallel smdy.Arch Ophthalmol 2004 122 1667-1674. 

Since its introduction into clinical practice in 1876, pilocarpine has remained the most usefiil miotic for management of primary open-angle glaucoma, acute angle-closure glaucoma, and many secondary glaucomas. Pilocarpine is commercially arailable as an ophthalmic solution in concentrations from 0.25% to 10% (see Table 10-7). Pilocarpine is also commercially available as a 4% ophthalmic gel that is supplied in 3 5-g tubes. 

Topical ganciclovir has also been shown to be active against HSV keratitis. Ganciclovir gel is commercially available outside of the United States as a 0.15% ophthalmic gel. Two small trials indicated that topical ganciclovir and... 

Polyacrylamide forms water-based gels at concentrations around 4%w/v, which exhibit pseudoplastic behavior. A PAAm ophthalmic gel containing pilocarpine was compared with other gel vehicles the ocular bioavailability for the PAAm gel was three times greater than that of the aqueous control solution. The kinetics of ibuprofen release for crosslinked PAAm gels was studied. A kinetic model was proposed for swelling induced loading of insulin into crosslinked PAAm gels. ... 

The final example of a novel process development formulation involves a semi-solid ophthalmic gel containing a carbonic anhydrase inhibitor drug for the treatment of glaucoma. It is administered to the patient by extruding the gel from an ophthalmic tube into the conjunctival sac of the eye. The drug had a very low aqueous solubility. It was necessary to reduce the particle size of the drug to less than 10 pim and suspend it in a very thick carbomer gel vehicle, to increase the residence time of the gel and maximise corneal permeation. The formulation details are given below ... 

Figure 12.2 Steps in the process for the manufacture of a semi-solid ophthalmic gel suspension.

A ganciclovir ophthalmic gel formulation appears to be effective in treating HSV keratitis. Oral ganciclovir reduces hepatitis B virus (HBV) DNA levels and aminotransferase levels in chroiuc hepatitis B. 

A second ophthalmic gel, for the delivery of pilocarpine, is poloxamer407. This vehicle was chosen because of its low viscosity, optical clarity, and mucomimetic properties, and for its previous acceptability in ophthalmic preparations. This formulation enhanced pilocarpine activity, as indicated by miosis measurements in rabbits, compared to a pilocarpine aqueous solution of equal drug concentration. 

Comparative studies In 105 children aged under 6 years who were randomized for 12 weeks to betaxolol suspension (n = 34) or timolol maleate ophthalmic gel-forming... 

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. 

The safety and efficacy of 0.15% GCV ophthalmic gel for herpes simplex keratitis (HSK) have been reviewed (including four randomised clinical studies, of 377 patients in total) the GCV gel treatment was better tolerated than 1% trifluorothymidine (former HSK standard therapy), with overall reduced rates of eye irritation, visual blurring, and punctate keratitis [19 ]. The general role of GCV ophthalmic gel in HSK, including its side effects, is also reviewed elsewhere [20 ]. 

Sabin A, Hamrah P. Acute herpetic keratitis what is the role for ganciclovir ophthalmic gel Ophthalmol Eye Dis 2012 4 23-34. 

Lin T, Gong L, Sun XH, Zhao NQ, Chen W, Yuan HP, et al. Effectiveness and safety of 0.15% ganddovir in situ ophthalmic gel for herpes simplex keratitis - a multicenter, randomized, investigator-masked, parallel group study in Chinese patients. Drug Des Devel Ther 2013 7 361-8. 

Pathak, M.K., Chhabra, G., Patheik, K. Design and development of a novel pH triggered nanoemulsified in-situ ophthalmic gel of fluconazole ex-vivo transcomeal permeation, corneal toxicity and irritation testing. Drug. Dev. Ind. Pharm. 39(5), 780-790 (2013)... 

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