Stability of Non-aqueous Topical Tetracaine and Clotrimazole Solutions in Polypropylene Droptainer Bottles
Author(s): McPherson Timothy B, Neumann William L, Kolling William M
Issue: Nov/Dec 2013 - Volume 17, Number 6
View All Articles in Issue
Page(s): 508-511
Download in electronic PDF format for $75
Abstract: Tetracaine topical solution may improve patient adherence with topical clotrimazole therapy for fungal otitis externa. The chemical stability of tetracaine 1% and combination clotrimazole 1% with tetracaine 1% topical solutions was determined using a stability-indicating high-performance liquid chromatography assay. Propylene glycol and polyethylene glycol 400 were used as anhydrous solvents. Standard curves for tetracaine and clotrimazole were linear with r2 = 0.999. Clotrimazole did not degrade in either propylene glycol or polyethylene glycol 400 throughout the 90-day study period. Tetracaine degraded significantly in propylene glycol but not in polyethylene glycol 400. A beyond-use date of 90 days is supported for tetracaine and the combination clotrimazole-tetracaine solution in polyethylene glycol 400. A beyond-use date of 60 days is supported for tetracaine and the combination clotrimazole–tetracaine in propylene glycol.
Related Keywords: Timothy B. McPherson, PhD, William L. Neumann, PhD, William M. Kolling, PhD, tetracaine, clotrimazole, topical solutions, topical preparations, patient adherence, fungal otitis externa, stability, propylene glycol, polyethylene glycol 400, PEG 400, topical anesthetic, drug admixtures
Related Categories: EXCIPIENTS, PACKAGING, PAIN MANAGEMENT, PEER-REVIEWED, STABILITIES, COMPATIBILITIES, INFECTIOUS DISEASE