Erythromycin stinoprate

Ester derivatives of erythromycin, shown in Table 4, were synthesized soon after its discovery (124—126). They are readily prepared by acylation of the 2-hydroxyl group the neighboring 3r-dimethylamino group directs acylation to this site. Commonly used esters of erythromycin are propionate, acetate, ethyl succinate, and ethyl carbonate (30). 2r-Esters do not bind bacterial ribosomes, however, and consequently must be hydrolyzed back to the parent to exert antibacterial activity (127). Ester derivatives are still being prepared (128,129). 2,-0-Acetylerythromycin stearate, also known as erythromycin acistrate, is an example undergoing clinical trial (11,130,131). Two salts of 2,-0-propionyl-erythromycin, N-acetylcysteinate (erythromycin stinoprate) and mercaptosuccinate, were prepared to combine antibiotic and mucolytic properties in a single agent (132—134). 

Combinations of a 2 -ester and a lipophilic acid-addition salt have also been extensively employed. Erythromycin estolate (2 -propionate, lauryl sulphate salt) has been widely used due to its better oral absorption than other forms of erythromycin [62, 67, 68]. Similar results have been found with erythromycin acistrate (2 -acetate, stearate salt) [69, 70], which is reported to be less hepatotoxic in animals than other forms of erythromycin [71], Two salts of 2 -propionylerythromycin,A-acetyIcysteinate (erythromycin stinoprate) and mercaptosuccinate, are being investigated as combinations of an antimicrobial and mucolytic agent [72-74],... 

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