Wiktionary
pivampicillin
n. A pivaloyloxymethyl ester of ampicillin.
Wikipedia
Pivampicillin
Pivampicillin is a pivaloyloxymethyl ester of ampicillin. It is a prodrug, which is thought to enhance the oral bioavailability of ampicillin because of its greater lipophilicity compared to that of ampicillin.