A GREAT deal has been written in the ophthalmologic literature about the importance of the hydrogen ion concentration and the tonicity of ophthalmic therapeutic solutions. Much of the published material is not in a form that is readily usable by the practicing ophthalmologist. We decided to investigate the practical limits of variability of these two factors and to evaluate their importance. Our aim is to present here what we believe to be the best solutions, based on present knowledge, for practical prescribing and feasible compounding of solutions containing most of the frequently used ophthalmic drugs.
Recently, Swan1 summarized the factors known at present which influence the permeability of the cornea by therapeutic agents. He pointed out that the tonicity of the tears, as reported by various workers in terms of the sodium chloride equivalent, varies from 0.9 to 1.4 per cent. He stated elsewhere2 that solutions with tonicity
MARTIN FN, MIMS JL. PREPARATION OF OPHTHALMIC SOLUTIONS WITH SPECIAL REFERENCE TO HYDROGEN ION CONCENTRATION AND TONICITY. Arch Ophthalmol. 1950;44(4):561-572. doi:10.1001/archopht.1950.00910020571008