yield of about 50 70 with an hplc purity of about or greater than 97 the invention may also be performed to produce substantially pure or pharmaceutical quality tin mesoporphyrin chloride tin iv mesoporphyrin ix dichloride or stannsoporfin in large scale quantities such as quantities exceeding about 0 1 kg through and including multiple kilogram amounts by slight modifications of the above procedure such as increased reaction or drying times as appropriate based upon the increase in scale of the starting reactants temperature and pressure times likewise can be modified as needed within the scope of this invention the tin mesoporphyrin chloride product tin iv mesoporphyrin ix dichloride or stannsopofrin is obtained in the large scale production process in a yield of about 60 90 with an hplc purity of about 97 the invention will be further described for illustrative purposes with reference to the following specific experimental examples a 2000 ml hydrogenation vessel was charged with 40 0 g hemin 4 0 g 5 pd c 50 water by weight and 800 ml 96 formic acid since hemin and mesoporphyrin ix formate as well as all reaction intermediates are reportedly light sensitive materials care was taken throughout this entire procedure to minimize the exposure of the reaction to visible or ultraviolet light the vessel was flushed with a nitrogen flow for 10 minutes with vigorous stirring it was then pressurized to 50 psi with hydrogen for.