Comparison of gold levels and distribution in guinea pig serum.

Serum levels after oral administration of 30 mg/kg of sodium aurothiomalate (Myocrisin), triethylphosphine gold chloride, or triphenylphosphine gold chloride to guinea pigs indicated that all were orally absorbed. However, the serum gold level of triethylphosphine gold chloride was three to four times that of Myocrisin or triphenylphosphine gold chloride and was comparable with the serum level produced when the same dose of Myocrisin was injected intramuscularly. A comparative time-course study between intramuscular administration of Myocrisin and oral administration of triethylphosphine gold chl;ride indicated that during the first 24 hours after intramuscular injection of Myocrisin, a large fraction of the gold was not protein-bound, whereas all detectable gold in serum after oral administration of triethylphosphine gold chloride was protein-bound. Gold levels in the separated protein fractions indicate that the gamma-globulin level after oral administration of triethylphosphine gold chloride is approximately three times higher after 24 hours than with intramuscular Myocrisin.