RENAL SPECIFIC DELIVERY OF SULFAMETHOXAZOLE IN THE RAT BY COUPLING TO THE LOW-MOLECULAR-WEIGHT PROTEIN LYSOZYME VIA AN ACID-SENSITIVE LINKER

Sulfamethoxazole (SM) was converted to a renal specific drug targeting preparation by coupling the drug to egg-white lysozyme via an acid-sensitive cis-aconityl linker (1:1). Due to this chemical manipulation SM was rapidly distributed to the kidney. Both in vitro and in vivo data indicate that SM was uncoupled from the carrier by chemical hydrolysis in the lysosomes of proximal tubular cells, resulting in parent active drug at the target site. This concept is applicable to other drug-polypeptide conjugates which rapidly distribute to the kidney and might enable selective manipulation of renal (patho)physiology.