Development of a new HPLC method for the simultaneous determination of ticarcillin and clavulanic acid in pharmaceutical formulations.

A new HPLC method has been developed and validated for the simultaneous determination of ticarcillin (TIC) and clavulanic acid (CA) in pharmaceutical formulations. The HPLC separation was achieved on a beta-cyclodextrin column (Cyclobond I, 250 x 4.6 mm, 5 microm) with methanol-16 mM pH 6.0 ammonium acetate buffer (50 + 50, v/v) mobile phase at a flow rate of 0.8 mL/min. Detection was at 220 nm. Validation of the method was performed by evaluating specificity, robustness, accuracy, and precision. The calibration curves were linear in the range of 1-100 microg/mL for CA and 2-200 microg/mL for TIC. The LOQs based on the standard regression lines were 0.42 and 1.42 microg/mL for CA and TIC, respectively, and the LOD were 0.14 and 0.47 microg/mL, respectively. Total recoveries of synthetic mixtures (CA:TIC = 1:10, 1:15, and 1:30) were 99.25-100.99% for CA and 99.54-100.82% for TIC. Compared with the U.S. Pharmacopeia method, the proposed method has the advantage of a relatively low flow rate and short analysis time. The proposed method was successfully applied for the simultaneous determination of these two drugs in sterilized H20 and 5% dextrose injection solutions.

Application of MEKC for determination of ticarcillin and clavulanic acid in Timentin intravenous preparation.

A micellar electrokinetic chromatography method for simultaneous assay of ticarcillin and clavulanic acid in Timentin i.v. injection preparation was developed. This method ensures excellent separation of both components of Timentin preparation. The validation of the method was performed, and specificity, reproducibility, precision and accuracy were confirmed. The detection and quantitative limits for Timentin were established in the concentrations 0.04 and 0.08 mg/ml, respectively. The elaborated technique was compared with two methods routinely used-UV and high performance liquid chromatography (HPLC). The obtained results and their statistical analysis proved the same precision of all methods, however, no significant differences were observed between CE and HPLC.

Clavulanate-potentiated ticarcillin: high-performance liquid chromatographic assays for clavulanic acid and ticarcillin isomers in serum and urine.

High-performance liquid chromatographic assays for the determination of clavulanic acid and ticarcillin in biological fluids are described. The clavulanic acid assay uses serum ultrafiltrate and direct injection of diluted urine with reversed-phase ion-pair/counter-ion chromatography. The ticarcillin assay allows, for the first time, the separation and quantitation of two isomers of ticarcillin. The performance of these assays has been evaluated and found to be satisfactory for routine clinical use and thus the assays have been applied to the study of the pharmacokinetics of these analytes in a subject with renal failure.

Tobramycin inactivation by carbenicillin, ticarcillin, and piperacillin.

The in vitro and in vivo inactivation of tobramycin by carbenicillin, ticarcillin, or piperacillin was investigated by the enzyme immunoassay method in clinically employed dosages. After the addition of an 80-mg dose of tobramycin to 4- to 5-g doses of a penicillin in 100 ml of 0.9% saline or distilled water, the degradation profile of tobramycin appeared to follow a biexponential pattern of decay. Remarkable losses (30 to 40%) of tobramycin combined with carbenicillin or ticarcillin were observed within 1 h, as compared with the later decline. The combination of tobramycin with piperacillin was least inactivating. When the admixture of tobramycin with carbenicillin or piperacillin used in the in vitro study was infused to six volunteers over 1 h, the observed maximum concentrations of tobramycin were on the average 66 and 74% for carbenicillin and piperacillin, respectively, of that observed after tobramycin alone was given. In contrast, the value obtained for tobramycin in combination with piperacillin was close to 90% of the control value. The elimination half-lives of tobramycin combined with the penicillins were slightly shorter than those of tobramycin alone, indicating that the interaction occurs even in patients with normal renal function.

Ticarcillin serum and tissue concentrations in gynecology and obstetrics.

Ticarcillin tissue concentrations were determined in 77 patients following an infusion of 5 g over 30 min. The tissues studied in gynecology were endometrium, tube, ovary and myometrium. The relative tissue levels ranged from 17% to 30% of the corresponding serum concentrations when ticarcillin was administered once, and from 22% to 32% when the drug was infused repeatedly. In no case did these tissue levels exceed the serum concentrations. The mean relative tissue levels in early pregnancy (decidua, placenta, embryo) were 10% of the corresponding serum concentrations. Levels in late pregnancy were determined in the placenta, amniotic fluid and in serum from the umbilical cord artery and vein immediately after delivery. Maximal placenta concentrations of 30 mg/kg were determined; these declined exponentionally with half-lives of 2.8 and 1.3 h, respectively, following single and repeated dosings. Amniotic fluid levels increased from 10 mg/l immediately after the first infusion to 60 mg/l after the seventh infusion. Individual umbilical cord levels in the artery and vein were significantly different, indicating that the fetus has properties of a deep compartment. The total amount of ticarcillin excreted daily in the mother's milk was strictly correlated to its volume and ranged from 2-2.5 mg/l.

High-pressure liquid chromatographic assays for ticarcillin in serum and urine.

Rapid and sensitive high-pressure liquid chromatographic (HPLC) assays for ticarcillin in serum and urine have been developed. Sample pretreatment and optimized chromatographic conditions are presented for a C-18-bonded reversed-phase column used in an internal standard assay method. Ticarcillin has a retention time of or approximately 5.3 min at a flow rate of 1.5 ml/min for a mobile phase of acetonitrile-aqueous 0.06 M sodium biphosphate, pH 2.05, (50.5:100). In a two-step extraction procedure, the ticarcillin extraction efficiencies from serum and urine were 76.1 +/- 4.7 and 80.9 +/- 3.2% respectively. The assay sensitivity limit for ticarcillin in these fluids is approximately 1.0 microgram/ml. A comparison is made of the HPLC and microbiological assay results for ticarcillin in 20 different but equally divided serum samples obtained from two volunteers.

Cyst fluid antibiotic concentrations in polycystic kidney disease: differences between proximal and distal cysts.

The concentrations of several antibiotics were measured in the cyst fluid of six adult patients with polycystic kidney disease. Seventy-nine cysts were aspirated at surgery or autopsy. Sixty-one cysts could be categorized as arising from the proximal nephron and 16 from the distal nephron by cyst fluid to serum sodium ratios. Serum, urine, and cyst fluid were simultaneously analyzed for sodium, creatinine, and various antibiotics. Gentamicin, tobramycin, cephapirin, and ticarcillin were either undetectable or present in low concentrations in renal cysts. Cyst fluid antibiotic concentrations did not correlate with cyst volume or creatinine clearance. Cysts of proximal nephron origin had higher antibiotic concentrations than distal cysts. In one patient with normal renal function, inulin was undetectable in renal cysts after a continuous 36-hour i.v. infusion. Para-aminohippurate, however, was detected in the renal cysts of this patient. These data help explain the poor clinical response of infected renal cysts to antibiotic therapy. They also suggest that antibiotics and other solutes may enter cyst fluid across tubular cells in addition to entry by glomerular filtration.

Ticarcillin bioassay.

An accurate, plate diffusion bioassay for ticarcillin, utilizing the fast-replicating Beneckea natriegens and 4% salt agar, is described in this report. Zones of inhibition were well defined after 3 h, and the limit of sensitivity was around 5.0 mug/ml. The assay is simple to carry out, and duplicate assays can be performed on as little as 40 mul of serum.

Quantitation of carbenicillin disodium, cefazolin sodium, cephalothin sodium, nafcillin sodium, and ticarcillin disodium by high-pressure liquid chromatography.

High-pressure liquid chromatographic (HPLC) methods for the quantitation of carbenicillin, cefazolin, cephalothin, nafcillin, and ticarcillin were developed. The stability of 2% solutions of the antibiotics in normal saline and in 5% dextrose in water were studied at 24 and 5 degrees. The assays were conducted using a previously reported colorimetric method, and some assays also were performed using HPLC. For discolored solutions of cephalothin, the colorimetric method was not stability indicating. The percent relative standard deviations by HPLC based on six injections were 1.69, 0.94, 1.30, 1.59, and 1.6 for carbenicillin, cefazolin, cephalothin, nafcillin, and ticarcillin, respectively. Both carbenicillin and ticarcillin apparently may be mixtures of two isomers at equilibrium with each other. The shelflives recommended by the manufacturers at 5 degrees may be too conservative.

Clinical pharmacology of ticarcillin in the newborn infant: relation to age, gestational age, and weight.

Ticarcillin, a new penicillin derivative with greater in vitro activity against Pseudomonas than carbenicillin, was given as a single dose of 50 mg/kg intramuscularly on 61 occasions to 54 neonates and young infants. The serum concentrations and rate of elimination varied considerably depending upon gestational age, chronological age, and body weight. Peak serum concentrations depended principally upon the volume of distribution which approximated the extracellular fluid volume of the neonate. The plasma clearance and serum half-life of the drug were determined. From these pharmacokinetic data appropriate groupings according to age and body weight were made and dosages and intervals of administration predicted for clinical trials of efficacy with repeated doses.