Cefpodoxime proxetil is a slightly basic compound, absorbed from the gastrointestinal tract after oral administration and hydrolyzed to its parent moiety cefpodoxime acid by nonspecific esterases in the intestinal wall. The reasons for low oral bioavailability of cefpodoxime proxetil are mainly attributed to low water solubility (400μg/ml), typical gelation behavior of cefpodoxime proxetil particularly in acidic environments, and pre-absorption luminal metabolism of its ester side chain by digestive enzymes cholinesterases present in the intestinal lumen into cefpodoxime acid.

References:

- Kakumanu VK, Arora V, Bansal AK. Investigation of factors

responsible for low oral bioavailability of cefpodoxime proxetil.

Int J Pharm. 2006;317:155–60.

- Kakumanu VK, Arora V, Bansal AK. Investigation of physicochemical

and biological differences of cefpodoxime proxetil

enantiomers. Eur J Pharm Biopharm. 2006;64:255–9.

- Manciet SC, Huneau JF, Decroix MO, Tomb D, Farinotti R,

Chaumeil JC. Cefpodoxime proxetil esterase activity in rabbit

small intestine: a role in the partial cefpodoxime absorption. Int J

Pharm. 1997;149:241–9.

- Schellens JHM, Malingre MM, Kruijtzer CMF, Bardelmeijer HA,

Tellingen OV, SchinkelHA, et al.Modulation of oral bioavailability

of anticancer drugs: from mouse to man. Eur J Pharm Sci.

2000;12:103–10.