3,20-bis(ethylenedioxy)pregna-5,7-diene

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January 09, 2014 to August 11, 2014

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: The Guidelines for the Testing of Chemicals issued by the Ministry of Environmental Protection of the People’s Republic of China, 2004.5 (417, Toxicokinetics).”

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3,20-bis(ethylenedioxy)pregna-5,7-diene

EC Number:

243-175-0

EC Name:

3,20-bis(ethylenedioxy)pregna-5,7-diene

Cas Number:

19592-55-3

Molecular formula:

C25H36O4

IUPAC Name:

(1S,3aR,9aR,9bS,11aS)-9a,11a-dimethyl-1-(2-methyl-1,3-dioxolan-2-yl)-1,2,3,3a,6,8,9,9a,9b,10,11,11a-dodecahydrospiro[cyclopenta[a]phenanthrene-7,2'-[1,3]dioxolane]

Test material form:

solid: crystalline

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Strain: Sprague Dawley (SD) Rat
Grade: SPF
Sex and number: 10 females, 10 males. Age of animals: 5 weeks
Range of body weights of animals: at the start of administration, females 187.75-212.98 g, males 219.94-249.97 g.
Supplier: Beijing Vital River Laboratories Animal Technology Co. Ltd.

Animals were housed and fed by accredited personnel in barrier system of National Beijing Center for Drug Safety Evaluation and Research of Academy of Military Medical Sciences, the Certificate code of the facility was SCXK-(Army) 2007-008. The temperature of the experimental room was range from 20℃ to 25℃, the relative humidity from 40 to 70 percent, and the illumination cycle was 12 hours light / 12 hours dark. Transparent polycarbonate boxes as cages were used for rat feeding. Group, 3 to 5 animals per cage, was used. Study No., test substance No., animal code, group, sex, and dose were labeled on the cages.

Animals were provided standard feed produced by Beijing Keao Xieli Feed Co. Ltd. Qualification code of the feed was SCXK (JING) 2005-007. Animals were provided pure water produced by SJD water machine with bottles. Feed and water were available to the animals ad libitum.

All animals were quarantined and observed for 7 days. During this period, any abnormalities of animals were not observed. Clinical Veterinarian checked the animals and issued quarantine inspection report before the animals were used in study.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

0.5% suspension

Details on exposure:

toxicokinetic study IV and oral single dose and repeat dosing: Volume of administration: 10 ml/kg.
The Toxicokinetics of Proketal (SD Rat, Repeated Oral Gavage Administration) : Three groups: first exposure group (i.e. dosage of single oral gavage administration test), 2nd and 3rd exposure group.

Duration and frequency of treatment / exposure:

toxicokinetics study IV: single dose
toxicokenetic study oral, rat: single dose
The Toxicokinetics of Proketal (SD Rat, Repeated Oral Gavage Administration) : exposed evey 6 days continuously. Last exposure group 7 days continuously.

Doses / concentrations

Remarks:

Doses / Concentrations:
toxicokinetics study: IV 2 mg/kg
toxicokenetic study oral, rat:50 mg/kg and 1000 mg/kg
The Toxicokinetics of Proketal (SD Rat, Repeated Oral Gavage Administration) : 50 mg/kg

No. of animals per sex per dose / concentration:

all toxicokinetics study (IV and oral): 4 SD rats, 2 males and 2 females.

Control animals:

no

Details on dosing and sampling:

The Toxicokinetics of Proketal (SD Rat, Single Intravenous Administration) and (SD Rat, Single Oral Gavage Administration)
PHARMACOKINETIC STUDY (Absorption, distribution, excretion)
- Tissues and body fluids sampled, blood,
- Time and frequency of sampling: blood samples collection were before administration, 1 min, 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 6
h, 8 h, 12 h, and 24 h after administration.

Repeat dose study: 2nd exposure group: Trough concentration determination group: Blood samples were collected before administration every day and 24 h after last exposure, to determine trough concentration.

Repeat dose 3rd group. Blood samples, 0.1-0.2 ml, will be taken from orbital venous plexus and anticoagulated by heparin. The points of blood samples collection were before administration, 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 6 h, 8 h, 12 h, 24 h, 36 h and 48 h after administration on 7
th da y.

Statistics:

Calculation of kinetic parameters
Test data will be analyzed by DAS pharmacokinetics program, to calculate the main kinetic parameters: Cmax, VB., F,Tmax, MRT, AUC, t1/2, and etc.

Results and discussion

Preliminary studies:

The rats were given Proketal by intravenous injection administration at 2 mg/kg, The plasma concentration-time profile of Proketal fit three-compartment open model. Based on the results, the apparent volume of distribution (Vz) of Proketal in rats was 7.33±1.51 L/kg, much more than the total body water content. It was suggested that Proketal was distributed to the whole body of rat, and probably concentrated in some sites of the body.

The elimination half-life (t1/2) was 3.84±1.66h,
95% of Proketal was cleared from the body during 17.28 hours (4.5 times of half-life).
The clearance (CLz) was 1.48±0.60 L/h/kg. The results above indicated that there were extensive distribution and slow elimination of
Proketal in rats, and there was no gender difference in basic toxicokinetic characteristics of Proketal.

Toxicokinetic / pharmacokinetic studies

Details on absorption:

It was expressed as nonlinear dynamics in dose range of 50 to 1000 mg/kg. The absorption presented trend of saturation at 1000 mg/kg. The fractions of absorption at the doses of 50 and 1000 mg/kg were 0.89±0.67% and 0.33±0.15% respectively, the absorption extent was very low. The system exposure of Proketal in rats was increased slightly after repeated-dose oral gavage adminstration for 7 days.

Details on distribution in tissues:

Proketal was distributed to the whole body of rat by intravenous administration, and probably concentrated in some sites of the body.

Details on excretion:

95% of Proketal was eliminated in the body during 17.28 hours.

Toxicokinetic parameters

Toxicokinetic parameters 1

Test no.:

#3

Toxicokinetic parameters:

other: elimination half-life ( t 1/2z ) were 5.94±2.38h and 4.18±0.70h

Toxicokinetic parameters 2

Test no.:

#3

Toxicokinetic parameters:

AUC: AUC 0-t of the first and the last exposure were 339.91±257.22 ng·h·mL -1 and 384.07±70.72 ng·h·mL -1

Toxicokinetic parameters 3

Test no.:

#3

Toxicokinetic parameters:

Cmax: 38.72±2.88 ng/mL (first) and 45.75±4.40 ng/mL (last)

Toxicokinetic parameters 4

Test no.:

#2

Toxicokinetic parameters:

AUC: AUC 0-t were 339.91±257.22 ng·h·mL -1 (50 mg/kg) and 2540. 18±1159.26 ng·h·mL -1 (1000 mg/kg)

Toxicokinetic parameters 5

Test no.:

#2

Toxicokinetic parameters:

other: limination half-life (t1/2z) were 5.94±2.38h (50 mg/kg) and 5.37±2.05h (1000 mg/kg)

Toxicokinetic parameters 6

Test no.:

#1

Toxicokinetic parameters:

half-life 1st: 3.84±1.66 elimination half life

Toxicokinetic parameters 7

Test no.:

#1

Toxicokinetic parameters:

other: clearance (CLz) was 1.48±0.60 L/h/kg.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): low bioaccumulation potential based on study results
The kinetic characteristics of absorption of Proketal in rat body were:
It was expressed as nonlinear dynamics in dose range of 50 to 1000 mg/kg. At the dose of 1000 mg/kg, oral absorption presented trend of saturation. The rates of absorption at the doses of 50 and 1000 mg/kg were 0.89±0.67% and 0.33±0.15% respectively; the rates were low.

Proketal was distributed to the whole body of rat by intravenous administration, and concentrated in some parts of the body, 95% quantity of Proketal was cleared from the body during 17.28 hours.

The concentration of Proketal in the body was increased slightly through repeated oral gavage administration for a week.