Pharmacokinetics of Sulphamethoxazole in Man

Abstract

A high performance liquid chromatography method for the determination of sulphamethoxazole and its metabolite N4-acetylsulphamethoxazole is described. The renal excretion rate and cumulative renal excretion of sulphamethoxazole is markedly influenced by urinary pH. With constant urinary pH, the renal excretion rate and the renal clearance of sulphamethoxazole is dependent on the urine flow. The renal clearance of the metabolite N4-acetylsulphamethoxazole is not influenced by urinary pH or urine flow. No clear acetylator phenotype could be detected in the group of volunteers studied. The extent of acetylation depends on the amount of sulphamethoxazole available for acetylation, thus indirectly on the urine pH and flow.

Pharmacokinetics, acetylation‐deacetylation, renal clearance, and protein binding of sulphamerazine, N4‐acetylsulphamerazine, and N4‐trideuteroacetylsulphamerazine in ‘fast’ and ‘slow’ acetylators

“…5 per cent (SEM) and its metabolite 93.2+ 1. 8 per cent (SEM). It can be concluded that protein binding of parent compound and metabolite is not different in 'fast' and 'slow' acetylators (p = 0.1 5).…”

Determination of eight penicillins in serum from cattle and pigs by generic HPLC method

“…Several HPLC methods have been reported for determination of amoxicillin [1,2,4,[5][6][7][8][9][10], penicillin G [11][12][13], penicillin V [13,14], ampicillin [1,3,6,15,[16][17][18][19][20][21], oxacillin [22], cloxacillin [13,15,, nafcillin [22] and dicloxacillin [13,22,23] in biological fluids. A few methods describe determination of two [6,15,23], or at most 4 [13,22], of these penicillins.…”

“…A few methods describe determination of two [6,15,23], or at most 4 [13,22], of these penicillins. Sample preparation techniques reported for plasma or serum include dilution [23], ultrafiltration [6, t 3, 16], deproteinisation with trichloroacetic acid [3,17,21], perchloric acid [1,4] or methanol [15], deproteinisation with perchloric acid and dichloroethane [2], deproteinisation with acetonitrile and extraction with dichloromethane [22,25], deproteinisation with trichloroacetic acid followed by derivatisation and extraction with diethyl ether [17], extraction with dichloromethane from acid solution [23,24], SPE of diluted sample [7,10,12,14,16,20], deproteinisation with sulphuric acid and sodium tungstate followed by SPE [11], on-line dialysis and SPE of buffered samples [8] and column-switching techniques on diluted or deproteinised samples [4,9,18,19]. in most cases ultraviolet (UV) detection is at wavelengths close to 230 nm.…”

Assay of trimethoprim, sulfamethoxazole and its N4‐acetyl metabolite in biological fluids by high‐pressure liquid chromatography

“…Recent papers on the HPLC assay of co-trimoxazole [21,22] suggested direct reversed-phase chromatography of serum and plasma following protein precipitation. This simplified sample preparation is preferred by many analysts because it is fairly fast and useful in special situations, such as are encountered in toxicological hospital laboratories and emergency rooms.…”

“…The low concentration of pertinent substances makes the sensitivity by this method [21] too low for pharmacokinetic studies. Bury's paper [22] describes a procedure requiring two different chromatographic determinations for SMZ and TMP respectively (excluding the SMZ N4-acetyl metabolite), necessitating two chromatographic instruments or extended analysis times.…”