Registration Dossier

Administrative data

Endpoint:
basic toxicokinetics in vivo
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
02-AUG-2012 to 12-MAY-2014
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
This GLP-compliant study was well documented, although it differed from the OECD guideline 417 (in particular, a lower number of animals, and only males). Only plasma analysis was performed. Due to low levels detected urine and faeces were not analysed. Levels in plasma following intravenous administration were below level of quantification to draw reliable conclusions.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2014
Report date:
2014

Materials and methods

Objective of study:
toxicokinetics
Test guideline
Qualifier:
according to guideline
Guideline:
other: Note for Guidance on Toxicokinetics: “A Guidance for Assessing Systemic Exposure in Toxicology Studies”, CPMP/ICH/384/95
Deviations:
not specified
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
1,1,2,2,3,3,4,4-octafluoro-1,4-diiodobutane
EC Number:
206-788-4
EC Name:
1,1,2,2,3,3,4,4-octafluoro-1,4-diiodobutane
Cas Number:
375-50-8
Molecular formula:
C4F8I2
IUPAC Name:
1,1,2,2,3,3,4,4-octafluoro-1,4-diiodobutane
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): 1,4-diiodoperfluorobutane
- Substance type: monoconstituent
- Molecular formula: C4F8I2
Radiolabelling:
no

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Crl: Sprague Dawley SD rats
- Source: Charles River Italy s.r.l.
- Age at study initiation: no data available
- Weight at study initiation: 261 to 264 g
- Fasting period before study: no data available
- Housing: in a limited access rodent facility, in polysulphone solid bottomed cages measuring 59.5 x 38.0 x 20 cm
- Individual metabolism cages: yes (1 rat per cage)
- Diet: ad libitum, via a commercially available laboratory rodent diet (4 RF 21, Mucedola S.r.l. / Via G. Galilei 4 - 20019 Settimo Milanese (MI) / ITALY)
- Water: ad libitum, via water bottles
- Acclimation period: 11 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 2 °C
- Humidity: 55 ± 15%
- Air changes: ca. 15 to 20 air changes per hr
- Photoperiod: 12 hrs dark / 12 hrs light

IN-LIFE DATES: From 09-AUG-2012 to 22-AUG-2012

Administration / exposure

Route of administration:
other: oral gavage ; intravenous
Vehicle:
other: corn oil for the oral administration; 10% DMSO in physiological saline (NaCl 0.9%) for the intravenous administration
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
The required amount of test substance was dissolved/suspended in the vehicle and brought to the final volume appropriate for the corresponding concentration (10 mg/mL). The formulation was prepared on the day of dosing. The concentrations was calculated and expressed in terms of test item corrected for the purity (98.2 %).

VEHICLE
- Justification for use and choice of vehicle (if other than water): no data available
- Concentration in vehicle: 10 mg/mL for the oral administration; 4 mg/mL for the intravenous administration
- Amount of vehicle (if gavage): 10 mL/kg bw for the oral administration; 2.5 mL/kg for the intravenous administration
- Lot/batch no., purity: no data available

HOMOGENEITY AND STABILITY OF TEST MATERIAL: no data available
Duration and frequency of treatment / exposure:
Single administration
Doses / concentrations
Dose / conc.:
10 mg/kg bw (total dose)
Remarks:
single administration
No. of animals per sex per dose / concentration:
3 males per group
Control animals:
no
Details on study design:
- Dose selection rationale: the dose level administered by oral route was selected based on information from previous studies. Regarding the intravenous route, a preliminary toxicity screening was carried out to confirm that the initial dose level of 10 mg/kg, instead of 20 mg/kg as specified in the Study Protocol, was suitable for the study.
- Rationale for animal assignment (if not random): not applicable
Details on dosing and sampling:
PHARMACOKINETIC STUDY (Absorption, distribution, excretion)
* ORAL TOXICOKINETIC STUDY
- Tissues and body fluids sampled: plasma, urine, faeces
- Time and frequency of sampling: plasma sampling (0.45 mL taken from the tail vein) at 2, 4, 6, 8, 24, 48 hrs after dosing; urine and faeces samples were separately collected at time intervals 0-24 and 24-48 hr post-dose.

* INTRAVENOUS TOXICOKINETIC STUDY
- Tissues and body fluids sampled: plasma
- Time and frequency of sampling: sampling at 5, 30 min and 3, 6, 24, 48 hrs after dosing

Plasma preparation:
Tubes were centrifuged at room temperature (13000 rpm for 5 minutes) and the plasma was divided in three aliquots, where possible (the first and the second of at least 100 μL and the third with the remaining amount of plasma) and frozen at -20°C, pending bioanalysis.

Urine and Faeces samples:
At the end of each interval, faeces and urine were separately collected. A cage wash was performed with approximately 10mL of water. Urine sample(s) and the respective volume of water used for the cage wash were pooled for each animal and mixed; the total volume was measured. Faeces were also weighed. Urine and faeces samples were frozen and stored at -20° C. No analysis was performed in this study.

Plasma analysis:
The plasma samples were assayed to determine 1,4-diiodoperfluorobutane in rat plasma according to two different validated analytical method with two different applicability ranges. The validation of the method was performed in the range from 204.0 ng/mL to 1020 ng/mL (High range) and from 94.27 ng/mL to 471.4 ng/mL (Low range).
For the calculation the values indicated as BLOQ (below the limit of quantification) were considered as 1/2 of limit of detection (LOD). The limit of detection was expressed as 1/3 of the LLOQ (lower limit of detection).

The following toxicokinetic parameters were obtained or calculated from the individual plasma values of animals treated by oral and intravenous dosing:
* Cmax: maximum (peak) observed test item concentration;
* tmax: time to reach peak or maximum test item concentration;
* t½: elimination half-life associated with terminal slope (λZ) of a semilogarithmic concentration-time curve;
* AUC (0-tlast): area under the concentration-time curve calculated by the linear trapezoidal rule, from t=0 (pre-dose) to tlast (last quantifiable concentration);
* AUC: area under the plasma concentration-time curve from time zero to infinity.

Bioavailability could be determined as follows:
F = (AUC oral/ AUC IV) x (Dose IV / Dose oral)

OTHER:
- Mortality: throughout the study, all animals were checked early in each working day and again in the afternoon. No necropsy was performed.
- Clinical signs: all clinical signs were recorded for individual animals. Once before commencement of treatment and at least daily during the study, each animal was observed and any clinical signs were recorded.
- Body weight: each animal was weighed on the day of allocation to treatment group and on the day of dosing.
All surviving animals were sacrificed by carbon dioxide inhalation approximately 48 hrs after dosing, shortly after the last bleeding procedure.
Statistics:
All the toxicokinetic parameters were estimated or calculated by the Kinetica™, version 4.4.1, PK/PD Analysis (Thermo Electron Corporation Informatics, Philadelphia - USA) software.
Means and/or medians, standard deviations and coefficient of variations were obtained using a Microsoft Excel worksheet.
The determination of the parameters listed above and others depended upon the results of the toxicokinetic data.

Results and discussion

Preliminary studies:
A preliminary screening was carried out since no data on intravenous toxicity were available.
Two males were treated: one male received the vehicle (50% DMSO in physiological saline NaCl 0.9%) and one male received 10 mg/kg of the test item (dose volume of 1 mL/kg with an injection rate of 0.5mL/min). Both animals showed red colouration of the urine 30 minutes after dosing. Animals were sacrificed after 48 hrs and no clinical signs were observed.
A second trial was carried out and two additional males were treated: one received the vehicle (10% DMSO in physiological saline Na Cl 0.9%) and one 10 mg/kg of the test item (dose volume of 2.5 mL/kg with an injection rate of 0.5mL/min). Animals did not show clinical signs and therefore these conditions were used for the main study.
No mortality occurred in this phase of the study.

Toxicokinetic / pharmacokinetic studies

Details on absorption:
No data available. Detection of the substance in plasma indicated some absorption from the gastrointestinal tract but the fraction absorbed could not be determined as the plasma concentrations following intravenous administration were found below the quantification limit.
Details on distribution in tissues:
No data available
Details on excretion:
No data available. The faeces and urine samples collected were not analysed as part of this study.
Toxicokinetic parametersopen allclose all
Key result
Toxicokinetic parameters:
Cmax: 120.57 +/- 31.40 ng/ml
Remarks:
mean from 3 males, oral route 10 mg/kg
Key result
Toxicokinetic parameters:
Tmax: 7.3 +/- 1.2 hours
Remarks:
mean from 3 males, oral route, 10 mg/kg
Key result
Toxicokinetic parameters:
half-life 1st: 15.33 ± 3.06 hours
Remarks:
mean from 3 males, oral route, 10 mg/kg

Metabolite characterisation studies

Metabolites identified:
not measured

Bioaccessibility (or Bioavailability)

Bioaccessibility (or Bioavailability) testing results:
No data available

Any other information on results incl. tables

No mortality occurred. No clinical signs were observed in males receiving the test item by oral or intravenous administration. No significant body weight changes were noted during the study.

 

Toxicokinetic parameters in plasma after single oral administration – individual and mean data

Dose (mg/kg)

Rat number

Cmax (ng/mL)

Tmax (h)

AUC0-tlast (ng*h/mL)

AUC0-inf (ng*h/mL)

t½ (h)

10

8

129.4

6

2792.6

3165.18

16

10

146.6

8

3931.72

4236.94

12

12

85.7

8

1840.29

2147.93

18

Mean ± SD

120.57 ± 31.40

7.3 ± 1.2

2854.87 ± 1047.10

3183.35 ± 1044.62

15.33 ± 3.06

 SD = Standard deviation

Plasma dosages on day 1 - oral administration (ng/mL)(LLOQ high range)

Sampling times (hours)

Animal No.

2

4

6

8

24

48

91440008

91440010

91440012

BLOQ (77.59)

BLOQ (83.57)

BLOQ (146.5)

BLOQ (93.29)

BLOQ (75.23)

BLOQ (78.36)

BLOQ (108.11)

BLOQ (111.4)

BLOQ (82.22)

BLOQ (84.14)

BLOQ (118.3)

BLOQ (82.30)

BLOQ (61.94)

BLOQ (84.40)

BLOQ

BLOQ

BLOQ

BLOQ

n

mean

SD

CV%

3

n/a

n/a

n/a

3

n/a

n/a

n/a

3

n/a

n/a

n/a

3

n/a

n/a

n/a

3

n/a

n/a

n/a

3

n/a

n/a

n/a

BLOQ = below the limit of quantification. Values were considered as zero in calculations.

Validation high range: from LLOQ = 204 ng/mL to ULOQ = 1020 ng/mL

n/a = not applicable

Plasma dosages on day 1 - oral administration (ng/mL) (reanalysis with LLOQ low range)

Sampling times (hours)

Animal No.

2

4

6

8

24

48

91440008

91440010

91440012

77.53

87.84

194.5

104.3

73.72

79.03

129.4

135.0

85.56

88.82

146.6

85.70

51.22

89.26

BLOQ (15.71)

BLOQ (15.71)

BLOQ (15.71)

BLOQ (15.71)

n

mean

SD

CV%

3

120.0

64.70

53.90

3

85.70

16.34

19.07

3

116.7

27.07

23.21

3

107.0

34.30

32.04

3

52.06

36.78

70.65

3

15.71

-

-

BLOQ = below the limit of quantification. Values were considered as ½ of limit of detection (LOD) in calculations.

LOD = 1/3 of LLOQ

Validation low range: from LLOQ = 94 ng/mL to ULOQ = 1020 ng/mL

n/a = not applicable

Applicant's summary and conclusion

Conclusions:
On the basis of the test substance levels measured in the plasma samples, it was not possible to perform any toxicokinetic evaluation for oral and intravenous administration.
Executive summary:

The purpose of this study was to investigate the toxicokinetic profile of the test substance in rats after single oral or intravenous administration.

 

One group of 3 male rats was treated orally with the test item, by gavage, at the dose level of 10 mg/kg. Animals were individually bled at 2, 4, 6, 8, 24 and 48 hrs after dosing. In addition, urine and faeces samples were individually collected from the same animals at the following intervals: 0-24 and 24-48 hrs. In parallel, another group of 3 male rats was treated intravenously with the test item at the dose level of 10 mg/kg. Animals were individually bled at 5, 30 min and 3, 6, 24 and 48 hrs after dosing. Animals were sacrificed shortly after the last bleed and no necropsy was performed.

 

Regardless of the administration route, no mortality occurred. No clinical signs were observed either in males receiving the test item by oral or intravenous administration. In addition, no significant body weight changes were noted during the studies.

 

Following the single oral administration of the test item, the plasma samples were assayed to determine the test substance levels according to two different validated analytical methods with two different applicability ranges. The drug concentration-time profile following single oral administration indicated that all males were exposed to the test item at 10 mg/kg. The exposure for all animals was found with Cmax  values measured between 6 and 8 hrs after dosing. One out of three males showed a lower exposure compared to the others. The half-lives were between 12 and 18 hrs after dosing.

The results obtained from analysis of the plasma samples following were below the limit of quantification for intravenous administration.

 

On the basis of the test substance levels measured in the plasma samples, it was not possible to perform any toxicokinetic evaluation for oral and intravenous administration.