Nitrogen-Phosphorous Detection of Phencyclidine in Blood Serum

Relative Bioavailability of Chlorthalidone in Humans: Adverse Influence of Polyethylene Glycol

“…This particular phenomenon was observed only for phenobarbital, however, and not for pentobarbital, barbital, or barbituric acid. It was demonstrated more recently using the in situ rat gut technique, that both polyethylene glycol 4000 and 6000 retarded the rate of disappearance of salicylic acid from the gut (9). The clinical data in this report corroborate these in uitro observations on the potential influence of polyethylene glycol on drug dissolution and/or absorption.…”

“…Used as demulcents, polyethylene glycols are found in water-soluble ointment bases, as ingredients of lotions and suppositories, and as tablet coatings. Although polyethylene glycol 4000 results in improved solubility of chlorthalidone in water, the data in this investigation, as well as previous reports (8,9), indicate that it is not an appropriate constituent for use in chlorthalidone bioavailability studies. Its use in bioequivalency investigations for other drugs should probably be discouraged until it can be shown to be inert in the test system employed.…”