[2S-[2α,5α,6β(S*)]]-6-[[[[(4-ethyl-2,3-dioxopiperazin-1-yl)carbonyl]amino]phenylacetyl]amino]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

basic toxicokinetics in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Objective of study:

absorption

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: 8-week-old male Sprague–Dawley rats (300–350 g, four rats/compound) were administered 50 mg/kg bw of piperacillin in 5% DMSO/water by oral gavage, or in physiological saline by intravenous injection. Blood samples were taken from the tail vein over a 2 h period (0, 5, 10, 15, 30, 60, 90, 120 min) and analysed by LC-MS/MS.
- Parameters analysed / observed: concentration (μg/mL) vs. time, AUC (μg h/mL), oral uptake.
- Animal studies were undertaken with approval from the University of Queensland Ethics Committee (approval #SMMS/002/08/ARC)

GLP compliance:

not specified

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Sigma–Aldrich (Castle Hill, NSW, Australia)

Radiolabelling:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8 weeks old
- Weight at study initiation: 300–350 g

Route of administration:

oral: gavage

Vehicle:

physiological saline

Duration and frequency of treatment / exposure:

single dose

Dose / conc.:

50 mg/kg bw/day (nominal)

Remarks:

oral

Dose / conc.:

50 mg/kg bw/day (nominal)

Remarks:

i.v.

No. of animals per sex per dose / concentration:

4 males per dose

Control animals:

no

Details on study design:

ANALYTICAL METHOD
For LC–MS/MS experiments, a Phenomenex luna C18 column (5 mm, 50 mm x 2.0 mm) equipped with a C18 guard column (4 mm x 3.0 mm) was attached to the mass spectrometer and a 30–100% gradient of B in A over 4 min was used for elution at a flow rate of 0.5 mL/min with a 1:10 splitter upstream from the ionisation source (Shimadzu LC-10AT system). Data were acquired with Analyst 1.4 software (Applied Biosystems/MDS Sciex, Toronto, Canada).

Details on dosing and sampling:

TOXICOKINETIC / PHARMACOKINETIC STUDY (Absorption, distribution, excretion)
- Tissues and body fluids sampled (delete / add / specify): blood, plasma.
- Time and frequency of sampling: At regular time points (0, 5, 10, 15, 30, 60, 90, 120 min), blood samples (200 mL) were collected in heparinised tubes by tail vein bleeding.
The rats were euthanised immediately after the experiment by inhalation of a 1:1 O2/CO2 mixture; death was further asserted by cervical dislocation. Blood samples were centrifuged for 20 min at 1717g and the plasma was collected, treated with acetonitrile (1:1,v/v) to precipitate the proteins and centrifuged. The supernatant was then collected for analyses by LC-MS/MS (or kept at -30ºC if analyses could not be run immediately).

Statistics:

Results were expressed as mean values standard error mean (SEM). Where applicable, statistical analysis of values was performed by one-way analysis of variance (ANOVA) of repeated measures to a significance level of 0.05 (p < 0.05), followed by Tukey’s post hoc test (multiple pairwise comparison of means). Computations were realised using GraphPad Prism v5.01 (GraphPad software, La Jolla, CA).

Type:

absorption

Results:

Oral absorption of the test item was 0.5%.

Type:

distribution

Results:

Intravenously administered, the test item shows a rapid distribution in the organism.

Type:

excretion

Results:

After intravenous administration, the test item is cleared rapidly from the circulatory system. After 1h it could not be detected.

Details on absorption:

The oral uptake of piperacillin was calculated from the AUC120 (mean area under the curve) and was expectedly very low (0.5%).

Details on distribution in tissues:

The i.v. curve (see Illustration, Fig. 7a) demonstrates a rapid distribution of piperacillin after injection with mean peak concentration of 70 mg/mL at around 5 min.

Details on excretion:

The antibiotic is then rapidly cleared from the circulatory system with virtually no drug detected after 1 h.

Key result

Test no.:

#1

Toxicokinetic parameters:

Tmax: 5 min

Metabolites identified:

not measured

Table 1. Area Under the Curve (AUC120) values for the in vivo pharmacokinetics profile of piperacillin alone (Oral and i.v.)

Compound	AUC120 (μg h/mL)	AUC120 (rel %)
Piperacillin sodium (i.v.)	1058.46	100
Piperacillin sodium (oral)	4.96	0.46

 

Conclusions:

Based on the results obtained for the analogue substance, the target substance is not available via oral route.

Executive summary:

A study to determine the oral uptake of the analogue substance piperacillin sodium was performed on male Sprague-Dawley rats (no TG, no GLP). Four 8-week-old males per group were administered 50 mg/kg bw of piperacillin in 5% DMSO/water by oral gavage, or in physiological saline by intravenous injection. Blood samples were taken from the tail vein over a 2 h period (0, 5, 10, 15, 30, 60, 90, 120 min) and analysed by LC-MS/MS. The oral uptake of piperacillin was calculated from the AUC120 (mean area under the curve) and was expectedly very low (0.5%). The data obtained for intravenous administration demonstrates a rapid distribution (mean peak concentration of 70 mg/mL at around 5 min) and rapid clearance from the circulatory system (no drug detected after 1 h). Based on the results obtained for the analogue substance, the target substance is not available via oral route.