Biotransformation of hetacillin to ampicillin in man

Reaction of Picolinamides with Ketones Producing a New Type of Heterocyclic Salts with an Imidazolidin-4-One Ring

“…For example, the half-life of the antibacterial drug hetacillin in aqueous solutions at pH 3–8 is approximately 30 min [ 34 ]. The main hydrolysis product, ampicillin, is responsible for over 90% of the biological activity of hetacillin [ 35 ]. The N’-alkylation improves the hydrolytic stability of imidazolidin-4-ones both in human plasma and aqueous buffer with pH 7.4 [ 19 ].…”

Evaluation of the Bioavailability of Sarpicillin, the Methoxymethyl Ester of Hetacillin, in Humans

“…Matsunaga et al (7) found that phenylbutazone gave three polymorphs, i.e., forms I, 11, and 111, among which the former two polymorphs (available commercially) were considered to be a stable form and one of the metastable forms, respectively. The mutual transformation among them by heating or through grinding and compression has been investigated.…”

“…Esters of penicillin, such as pivampicillin hydrochloride and hetacillin have been introduced in an effort to improve the properties of ampicillin. Hetacillin is susceptible to rapid hydrolysis both in uiuo and in uitro (6,7). However, this drug improves ampicillin bioavailability (S), and its activity depends on the formation of ampicillin.…”

Pharmacokinetics of β-Lactam Antibiotics

“…Within 10 min of an intramuscular injection, 68 % of the apparent serum antibacterial activity is attributed to ampicillin; at 60 min, 90%. Peak concentrations of ampicillin are attained in about 1 h (BROWN et al 1969). These observations strongly suggest that most of the administered dose is absorbed into the systemic circulation as unchanged hetacillin.…”