long as the resulting preparation is ophthalmically acceptable accordingly buffers include acetate buffers citrate buffers phosphate buffers and borate buffers acids or bases may be used to adjust the ph of these formulations as needed in a similar vein an ophthalmically acceptable antioxidant for use in the present invention includes but is not limited to sodium metabisulfite sodium thiosulfate acetylcysteine butylated hydroxyanisole and butylated hydroxytoluene other excipient components which may be included in the ophthalmic preparations are chelating agents the preferred chelating agent is edentate disodium although other chelating agents may also be used in place or in conjunction with it ingredient amount w v active ingredient about 0 001 5 preservative 0 0 10 vehicle 0 40 tonicity adjustor 1 10 buffer 0 01 10 ph adjustor q s ph 4 5 7 5 antioxidant as needed surfactant as needed purified water as needed to make 100 the actual dose of the active compounds of the present invention depends on the specific compound and on the condition to be treated the selection of the appropriate dose is well within the knowledge of the skilled artisan the ophthalmic formulations of the present invention are conveniently packaged in forms suitable for metered application such as in containers equipped with a dropper to facilitate the application to the eye containers suitable for dropwise application are usually made of suitable inert non toxic plastic material and generally contain between about 0 5 and about 15 ml solution the invention is further illustrated by the following non limiting examples which are summarized in the reaction scheme of fig1 through 3 wherein like numbers refer to the same compounds 1 4 diazabicyclo 2 2 2 octane 153 mg 1 36 mmol and butyl isocyanate 190 u03bcl 1 71 mmol were added sequentially to a solution.