Hyoscine

Endpoint summary

Description of key information

The most sensitive subchronic value of 45 mg/kg bw (five days a week) was determined in a NTP (National Toxicology Program) study conducted with rats in the 14 -weeks study (oral gavage). The exposure for five days per week under test conditions was extrapolated to seven days per week resulting in the NOAEL value of 32.14 mg/kg bw/day.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Justification for type of information:

The read-across justification is included as attachmant to Iuclid section 13.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

Clinical biochemistry and ophthalmological examination was not conducted

GLP compliance:

yes

Remarks:

Food and Drug Administration (FDA) Good Laboratory Practice Regulations (21 CFR, Part 58)

Limit test:

no

Species:

rat

Strain:

other: F344/N

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Simonsen Laboratories, Inc. (Gilroy, CA)
- Age at study initiation: approximately 6 weeks
- Average age at Necropsy: approximately 19 to 20 weeks
- Weight at study initiation: mean body weight: male 114 to 116 +-3 g, female 95+-1 to 98+-2g
- Housing: 5 per cage; Cages: Polycarbonate (Lab Products Inc., Maywood, NJ), changed twice weekly; Bedding: Beta Chips® (Northeastern Products Co., Warrensburg, NY); Cage filters: Reemay® spun-bonded polyester (Andico, Birmingham, AL); Racks: Stainless steel (Lab Products Inc., Maywood, NJ), rotated once every 2 weeks
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 12 days
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 to 25°C- Humidity (%): 45 to 66%
- Air changes (per hr): minimum of 10 changes/hour
- Photoperiod (hrs dark / hrs light): 12 hours/day fluorescent light

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

deionized

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Stability studies of the 11 and 0.2 mg/mL dose formulations were conducted by the analytical chemistry laboratory. For the 11 mg/mL formulation, samples were prepared by dissolving scopolamine hydrobromide trihydrate in deionized water and diluting to volume. Aliquots (5 mL) were mixed with internal standard solution (0.4 mg/mL acetophenone in acetonitrile) and were further diluted with 0.007 M aqueous sodium heptanesulfonic acid. The samples were then analyzed by HPLC using a Waters C18 Nova Pak column, with a mobile phase of water:acetonitrile (70:30), at a flow rate of 1.0 mL/minute, and with ultraviolet detection at 229 nm. For the 0.2 mg/mL formulation, samples were prepared by dissolving scopolamine hydrobromide trihydrate in deionized water and diluting to volume. Aliquots (7 mL) were mixed with internal standard solution (0.04 mg/mL propiophenone in acetonitrile) and were analyzed by HPLC with the same system used to analyze the 11 mg/mL formulation but with a mobile phase ratio of 75:25. The stability of the dose formulations was confirmed for at least 3 weeks at room temperature when stored in the dark or for at least 3 hours at room temperature and open to air and light.Periodic analyses of the dose formulations of scopolamine hydrobromide trihydrate were conducted at the study laboratory using ultraviolet/visible spectrometry for the 14-week studies. During the 14-week studies, dose formulations were analyzed every 6 to 8 weeks. All of the dose formulations analyzed during the 14-week studies were within 10% of the target concentration. For the 14-week , results of periodic referee analyses performed by the analytical chemistry laboratory indicated good agreement with the results of the study laboratory.

Duration of treatment / exposure:

14 weeks

Frequency of treatment:

once daily, 5 days per week

Remarks:

Doses / Concentrations:0, 15, 45, 135, 400, or 1,200 mg/kg bw

No. of animals per sex per dose:

10

Control animals:

yes

Details on study design:

- Sentinel program: The Sentinel Animal Program is part of the periodic monitoring of animal health that occurs during the toxicologic evaluation of chemical compounds. Under this program, the disease state of the rodents is monitored via serology on sera from extra (sentinel) animals in the study rooms. These animals and the study animals are all subject to identical environmental conditions. The sentinel animals come from the same production source and weanling groups as the animals used for the studies of chemical compounds.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes - Time schedule: twice daily
DETAILED CLINICAL OBSERVATIONS: Yes - Time schedule: weekly
BODY WEIGHT: Yes - Time schedule for examinations: initially, weekly, and at the end of the study
FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): feed conumption were recorded weekly by cage
OPHTHALMOSCOPIC EXAMINATION: No
HAEMATOLOGY: Yes - Time schedule for collection of blood: at the end of the study- Anaesthetic used for blood collection: Yes carbon dioxide- Parameters checked which were examined: hematocrit; hemoglobin; erythrocyte, reticulocyte, and nucleated erythrocyte counts; mean cell volume; mean cell hemoglobin; mean cell hemoglobin concentration; platelet count; and leukocyte count and differentials.
CLINICAL CHEMISTRY: No
URINALYSIS: No
NEUROBEHAVIOURAL EXAMINATION: No
OTHER:SPERM MORPHOLOGY AND VAGINAL CYTOLOGY: Yes; From rats receiving 0, 45, 135, 400 mg/kg- The parameters evaluated in males were sperm count, morphology, and motility.The right cauda, right epididymis, and right testis were weighed. Vaginal fluid samples were collected for up to 7 consecutive days prior to the end of the studies for vaginal cytology evaluations. The parameters evaluated in females were relative frequency of estrous stages and estrous cycle length.
NECROPSY: Yes- All animals were necropsied. Organs weighed included the brain, heart, right kidney, liver, lungs, right ovary, right testis, thymus and uterus.

Sacrifice and pathology:

HISTOPATHOLOGY/GROSS PATHOLOGY: Yes; Complete histopathologic examinations were performed on all control rats, male rats receiving 135 mg/kg or higher, female rats receiving 400 mg/kg or higher. In addition to gross lesions, tissue masses and associated lymph nodes, the tissues examined included: adrenal gland, bone and marrow, brain, clitoral gland, esophagus, heart, kidney, large intestine (cecum, colon, and rectum), small intestine (duodenum, jejunum, and ileum), liver, lung, lymph nodes (mandibular and mesenteric), mammary gland, nose, ovary, pancreas, parathyroid gland, pituitary gland, preputial gland, prostate gland, salivary gland, skin, spleen, stomach (forestomach and glandular stomach), testis with epididymis and seminal vesicle, thymus, thyroid gland, trachea, urinary bladder, and uterus.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Clinical findings included bilateral pupillary dilation in all dosed males and females and reddening of the eyes in 15 mg/kg males and 135, 400, and 1200 mg/kg males and females. Hyperactivity was visually observed in a few dosed males and females (males: 0 mg/kg, 0/10; 15 mg/kg, 0/10; 45 mg/kg, 1/10; 135 mg/kg, 1/10; 400 mg/kg, 0/10; 1200 mg/kg, 1/10; females: 0/10, 2/10, 5/10, 3/10, 1/10, 1/10). Hypoactivity was also visually observed in some other dosed males and females (males: 0/10, 0/10, 0/10, 0/10, 3/10, 3/10; females: 0/10, 0/10, 0/10, 1/10, 1/10, 5/10) and increased with increasing dose.

Mortality:

mortality observed, treatment-related

Description (incidence):

One female receiving 45 mg/kg, two males and one female receiving 135 mg/kg, six males and one female receiving 400 mg/kg, and eight males and seven females receiving 1200 mg/kg died during the study (Table 1).

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The final mean body weights and mean body weight gains of all dosed males and females were significantly lower than those of the control groups.The mortality and lower body weights of the dosed animals suggest that the dosed rats did not eat or drink as much as the controls and some dehydration would have occurred.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

The hematology data for rats in the 14 weeks study are listed in Table 2. Hematocrit, hemoglobin concentration, and/or erythrocyte count in male and female rats receiving 45 mg/kg or greater were slightly higher than those of the control groups. In general, these differences were most prominent in the 400 and 1200 mg/kg groups. Higher hematocrit, hemoglobin concentration, and erythrocyte count would be consistent with the hemoconcentration associated with dehydration (relative erythrocytosis). The mortality and lower body weights of the dosed animals suggest that the dosed rats did not eat or drink as much as the controls and some dehydration would have occurred. A minimal to mild mature neutrophilia, evidenced by higher segmented neutrophil numbers than those in the control group, occurred in all dosed male rats. Neutrophilia is often a result of an increased tissue demand for granulocytes due to inflammation. There was, however, no microscopic evidence of inflammation that could account for the neutrophilia. Thus, other mechanisms that alter granulopoiesis and/or rate of release from the bone marrow, redistribution of neutrophil life span could be considered. Other hematology differences were sporadic and were not treatment related.

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

The absolute and relative liver weights of 1200 mg/kg females were significantly greater than those of the control group. The absolute and relative thymus weights of 15, 45, 135, and 400 mg/kg males and females and 1200 mg/kg females were significantly lower than those of the control groups (Table 3).

Gross pathological findings:

no effects observed

Description (incidence and severity):

no adverse effects

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

no adverse effects

Histopathological findings: neoplastic:

no effects observed

Description (incidence and severity):

no adverse effects

Other effects:

no effects observed

Description (incidence and severity):

Sperm morphology and vaginal cytology parameters in dosed rats were similar to those in the control groups.

Details on results:

The mortality and lower body weights of the dosed animals suggest that the dosed rats did not eat or drink as much as the controls and some dehydration would have occurred. Some males (0/10, 0/10, 0/10, 2/10, 3/10, 4/10) and females (0/10, 0/10, 1/10, 1/10, 0/10, 3/10) died from esophageal obstructions consisting of feed and bedding material in the posterior pharynx. Tracheal obstruction occurred concurrently with esophageal obstruction as a result of food build-up in the oropharyngeal region. This condition is considered to be secondary to the inhibitory effects of scopolamine hydrobromide trihydrate on salivary gland secretions and on esophageal smooth muscle involved in swallowing. There were no other significant treatment-related gross or microscopic findings.

Key result

Dose descriptor:

NOAEL

Effect level:

45 other: mg/kg bw

Based on:

test mat.

Sex:

male

Basis for effect level:

mortality

Remarks on result:

other: dosage 5 days a week converted in 32.14 mg/kg bw/day

Dose descriptor:

NOAEL

Effect level:

400 other: mg/kg bw

Based on:

test mat.

Sex:

female

Basis for effect level:

mortality

Remarks on result:

other: dosage 5 days a week

Critical effects observed:

not specified

Table 1: Survival and Body Weights of Rats in the 14-Week Gavage Study of Scopolamine Hydrobromide Trihydrate

		Mean Body Weight°° (g)
Dose (mg/kg)	Survival°	Initial	Final	Change	Final Weight Relative to Controls (%)
Male
0	10/10	116 +-3	341 +-6	255 +-5
15	10/10	116 +-3	312 +-7**	197 +-6**	92
45	10/10	115 +-3	302 +-4**	188 +-5**	89
135	8/10°°°	114 +-3	300*-7**	186 +-5**	88
400	4/10°°°°	115 +-2	304 +-3**	188 +-7**	89
1,200	2/10 °°°°°	116 +-2	277 +-37**	163 +-30**	81
Female
0	10/10	96 +-1	203 +-2	107 +-2
15	10/10	97 +-1	193 +-2**	96 +-2**	95
45	9/10°°°°°°	98 +-2	196 +-2*	97 +-1**	97
135	9/10°°°°°°°	95 +-1	190 +-2**	96 +-3**	94
400	9/10°°°°°°	96 +-1	189 +-2**	93 +-3**	93
1200	3/10°°°°°°°°	95 +-1	192 +-6**	95 +-5**	94

* Significantly different(P<=0.05) from the control group by Williams’ or Dunnett’s test

** P<=0.01

°Number of animals survivinglnumber initially in group. Subsequent calculations are based on animals surviving to the end of the study

°°Weights and weight changes are given as mean f standard error

°°°Week of death: 7, 14

°°°°Week of death: 1, 2,7, 7,13, 13

°°°°°Week of death: 1, 1, 1, 3, 4, 5, 9, 14

°°°°°°Week of death: 4

°°°°°°°Week of death: 8

°°°°°°°°Week of death: 1, 2,5, 6, 7, 7

Table 2: Hematology Data for Rats in the 14-WeekGavage Study of Scopolamine Hydrobromide Trihydrate°

	Vehicle Control	15 mg/kg	45 mg/kg	135 mg/kg	400 rng/kg	1,200 mg/kg
Male
n	10	9	10	8	4	1°°
Hematocrit (%)	46.8+-0.5	46.2+-0.4	48.0+-0.3*	48.1+-0.3*	49.0+-0.4**	48.9
Hemoglobin (g/dL)	15.2+-0.2	15.3+-0.2	15.7+-0.1	15.9 f 0.1*	16.2+-0.1**	16.4
Erythroctes (10^6/µL)	9.39+-0.10	9.38+-0.10	9.63+-0.08	9.61 f 0.05	9.72+-0.11	9.58
Reticulocytes (10^6/µL)	0.50+-0.03	0.47+-0.02	0.52+-0.03	0.42 f 0.03	0.40+-0.04	0.46
Nucleated erythrocytes (10^3/µL)	0.03+-0.01	0.04+-0.01	0.01+-0.01	0.02+-0.01	0.02+-0.02	0.08
Mean cell volume (fL)	49.9+-0.4	49.1+-0.1	50.0+-0.2	50.0+-0.3	50.5+-0.3	51.0
Mean cell hemoglobin (pg)	16.2+-0.3	16.3+-0.1	16.3+-0.1	16.6+-0.1	16.7+-0.1	17 .1
Mean cell hemoglobin concentration (g/dL)	32.6+-0.5	33.2+-0.1	32.8+-0.2	33.1+-0.2	33.1+-0.1	33.5
Platelets ( 10^3/µL)	633.4+-20.8	638.8+10.6	655.8+-28.2°°°	620.6+-20.6	621.5+-21.3	601.0
Leukocytes (10^3/µL)	7.35+-0.44	6.96+-0.31	8.01+-0.36	7.59+-0.56	6.73+-0.57	8.40
Segmented neutrophils (10^3/µL)	1.14+-0.13	1.89+-0.28*	2.07+-0.17**	1.82+-0.20**	1.90+-0.12*	2.69
Lymphocytes (10^3/µL)	5.65+-0.35	4.68+-0.34	5.67+-0.41	5.37+-0.37	4.65+-0.45	5.38
Atypical lymphocytes (10^3/µL)	0.12+-0.03	0.08+-0.03	0.04+-0.02	0.08+-0.05	0.00+-0.00	0.00
Monocytes (10^3/µL)	0.35+-0.09	0.22+-0.06	0.17+-0.05	0.20+-0.04	0.07+-0.04*	0.34
Eosinophils (10^3/µL)	0.08+-0.03	0.09+-0.03	0.06+-0.01	0.11+-0.04	0.08+-0.02	0.00

	Vehicle Control	15 mg/kg	45 mg/kg	135 mg/kg	400 rng/kg	1,200 mg/kg
Female
n	9	10	9	9	8	3
Hematocrit (%)	46.9+-0.4	47.4+-0.6	48.1+-0.4	47.6+-0.4	49.0+-0.4**	49.1+-0.9*
Hemoglobin (g/dL)	15.6+-0.1	15.5+-0.2	15.9+-0.1	15.7+-0.2	16.2+-0.1**	16.4+-0.3*
Erythroctes (10^6/µL)	8.82+-0.07	8.88+-0.11	9.09+-0.07*	8.98+-0.10	9.17+-0.08*	9.26+-0.17*
Reticulocytes (10^6/µL)	0.41+-0.02	0.38+-0.02	0.42+-0.03	0.43+-0.03	0.43+-0.03	0.42+-0.05
Nucleated erythrocytes (10^3/µL)	0.02+-0.01	0.05+-0.01	0.03+-0.02	0.05+-0.02	0.05+-0.02	0.07+-0.07
Mean cell volume (fL)	53.1+-0.3	53.2+-0.2	52.7+-0.2	53.1+-0.2	53.5+-0.3	53.0+-0.0
Mean cell hemoglobin (pg)	17.7+-0.1	17.4+-0.1	17.5+-0.1	17.5+-0.1	17.7+-0.1	17.7+-0.1
Mean cell hemoglobin concentration (g/dL)	33.3+-0.2	32.6+-0.1*	33.1+-0.1	33.0+-0.2	33.1+-0.1	33.5+-0.2
Platelets ( 10^3/µL)	759.6+-39.6	764.3+-31.7	758.4+-27.5	807.4+-29.8	810.1+-44.3	698.7+-14.6
Leukocytes (10^3/µL)	6.37+-0.33	6.23+-0.40	6.21+-0.43	8.57+-0.38*	7.39+-0.59	5.97+-0.91
Segmented neutrophils (10^3/µL)	1.45+-0.11	1.30+-0.16	1.45+-0.12	2.16+-0.29	1.73+-0.17	1.68+-0.57
Lymphocytes (10^3/µL)	4.63+-0.36	4.68+-0.25	4.48+-0.42	6.15+-0.25*	5.35+-0.48	4.10+-0.38
Atypical lymphocytes (10^3/µL)	0.09+-0.04	0.03+-0.03	0.02+-0.01	0.04+-0.04	0.04+-0.03	0.04+-0.02
Monocytes (10^3/µL)	0.14+-0.05	0.15+-0.04	0.18+-0.06	0.15+-0.07	0.20+-0.08	0.08+-0.03
Eosinophils (10^3/µL)	0.06+-0.01	0.07+-0.02	0.07+-0.02	0.07+-0.03	0.04+-0.01	0.07+-0.04

* Significantly different (P<=0.05) from the control group by Dunn’s or Shirley’s test

** P<=0.01

° Mean f standarderror.Statisticaltests wereperformedonunroundeddata.

°°n=l; no standard error calculated

°°n=9

Conclusions:

Under the test conditions a NOAEL of 45 mg/kg bw (male) and a NOAEL of 400 mg/kg bw (female) was determined.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

32.14 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

According to Annex VI of regulation No 1272/2008 (CLP regulation) the test item is classified as Acute Toxic Category 1 (H310) referred to dermal toxicity to skin (has to be completed)

Additional information

From the National Toxicology Program (NTP) a technical report on the toxicology and carcinogenesis studies of the read across substance scopolamine hydrobromide trihydrate in rats and mice (gavage studies) (NTP TR 445) is available. This report includes i.a. data for repeated dose toxicity tests (subacute and subchronic) with mice and rats. All tests were conducted in accordance with good scientific principles.

For the subacute (16 -days) repeated dose toxicity study in rats (F344/N) and mice (B6C3F1) a NOAEL of >1200 mg/kg bw (female/male) was determined for rats and a NOAEL of 900 mg/kg bw (female/male) was determined for mice.

For the subchronic 14 -weeks repeated dose toxicity study in rats (F344/N) and mice (B6C3F1) a NOAEL of 45 mg/kg bw (male) and a NOAEL of 400 mg/kg bw (female) was determined for rats and a NOAEL of 400 mg/kg bw (male/female) in mice. Based on this data the lowest NOAEL of 45 mg/kg bw determined in the 14 -weeks study with rats was selected as key value. The exposure for five days per week under test conditions was extrapolated to seven days per week resulting in the NOAEL value of 32.14 mg/kg bw/day. For DNEL calculation the most sensitive NOAEL value was used, which was determined in the chronic carcinogenicity study (refer to section 5.8.).

All NOAEL values determined in this studies are based on survival.

Justification for classification or non-classification

Based on the available data, the substance will not be classified.