MITOMYCIN-C DISSOLVED IN A REVERSIBLE THERMOSETTING GEL - TARGET TISSUE CONCENTRATIONS IN THE RABBIT EYE

Aims-To determine whether a new, reversible thermosetting gel enhances mitomycin C transfer to target ocular tissues in the rabbit eye. Meth ods-A 0.1 ml solution of mitomycin C containing 0.22 mu g, 2.9 mu g, o r 28 mu g of the agent dissolved in a reversible thermosetting gel con sisting of methylcellulose, citric acid, and polyethylene glycol was i njected subconjunctivally in 30 New Zealand albino rabbits. Scleral an d conjunctival tissues were excised at 0.5, 1, 2, 4, or 24 hours after the injection and mitomycin C concentrations in these tissues were de termined by high performance Liquid chromatography. The concentration over time was approximated to a single exponential curve, and initial mitomycin C concentrations, time constants, and half life values were determined. Finally, the areas under the curves (AUCs) between 0.5 and 24 hours were calculated. Results-The mitomycin C concentrations in t he target tissues were dose dependent and decreased rapidly over 24 ho urs. Both the initial mitomycin C concentrations as well as AUCs in th ese eyes treated with mitomycin C, dissolved in a reversible thermoset ting gel, were higher than those in eyes treated similarly in a previo us study in which the gel was not used. Conclusion-Applied subconjunct ivally in the rabbit eye, mitomycin C dissolved in the reversible ther mosetting gel enhanced transfer of the agent to the sclera and the con junctiva.