2-Amino-3-Hydroxypyridine

Acute Toxicity Oral – Non-Human The acute oral toxicity of 2-amino-3-hydroxypyridine in propylene glycol was tested in Wistar rats.15 Three females and 3 males received a single gavage dose of the test substance at 300 mg/kg body weight and 3 females received a single dose at 1000 mg/kg. The rats were observed daily for mortalities and clinical signs of toxicity for 14 days. All 3 rats of the 1000 mg/kg dose group and 1 female in the 300 mg/kg dose group died immediately after dosing. Clinical signs in the 1000 mg/kg dose group included tremor, cramped posture, hunched posture, abnormal gait, salivation and chromodacryorrhea. Females in the 300 mg/kg were observed with the following clinical signs: restless, lethargy, tremor, hunched posture, uncoordinated movements, flat gait, quacking breathing, labored respiration, rales, shallow respiration, piloerection, salivation, chromodacryorrhea, pale, and ptosis. No clinical signs were observed in the 300 mg/kg dose group males. Surviving animals recovered from the symptoms between days 2 and 7, except for one female experiencing chromodacryorrhea and rales that recovered by day 15. No abnormal weight gain was observed in the males and slight weight loss or reduced body weight gain between days 8 and 15 in the females was not considered significant. At necropsy, the animals that died after the 1000 mg/kg dose  Distributed for Comment Only -- Do Not Cite or Quote had enlarged lungs with many dark red foci. In the female that died following the 300 mg/kg dose, reddish discoloration of stomach mucosa was observed. Enlarged mandibular lymph nodes were noted in the males. In this acute oral toxicity study, the median oral LD 50 was greater than 300 mg/kg body weight in male Wistar rats and less than 1000 mg/kg body weight in female Wistar rats. Based on the Organization for Economic Co-Operation and … [kırpıldı — bölüm toplam 17290 karakter]

2-Amino-3-hydroxypyridine is the heterocyclic aromatic compound that conforms to the structure in Figure 1.1 Physical and chemical properties of 2-amino-3-hydroxypyridine are found in Table 1. Figure 1. 2-Amino-3-hydroxypyridine is commonly used as a component of oxidative hair dyes.2 This ingredient acts as a “coupler” and reacts with a “precursor.” In a typical formulation, a precursor is activated via an oxidant, such as peroxide. The resultant activated precursor proceeds to couple with a coupler such as 2-amino-3-hydroxypyridine to form an in-situ coupled product that is purported to be the actual dye that colors hair in these types of oxidative hair dyes. Nitrosamine content has not been reported for 2-amino-3-hydroxypyridine. 2-Amino-3-hydroxypyridine bears a primary aryl amine. While many secondary amines and amides are readily nitrosated to form isolatable nitrosamines and nitrosamides, primary alkyl and aryl amines ultimately yield diazonium salts, instead of nitrosamines. The nitrogen atom of the pyridine core, however, has been shown to be susceptible to nitrosation.3 Of concern in cosmetics is the conversion (nitrosation) of nitrogen bearing ingredients into N-nitroso chemicals that may be carcinogenic. Of the approximately 209 nitrosamines tested, 85% have been shown to produce cancer in laboratory animals.4 Nitrosation can occur under physiologic conditions.5 Depending on the nitrosating agent and the substrate, nitrosation can occur under acidic, neutral, or alkaline conditions. Atmospheric NO 2 may also participate in nitrosation in aqueous solution.6 Accordingly, hair dyes with 2-amino-3-hydroxypyridine should be formulated to avoid the formation of N-nitrosopyridinium compounds. According to a 2002 study published by Cosmetics Europe, formerly known as Colipa,, the amount of 2- … [kırpıldı — bölüm toplam 7201 karakter]

2-Amino-3-hydroxypyridine is the heterocyclic aromatic compound that conforms to the structure in Figure 1.1 Physical and chemical properties of 2-amino-3-hydroxypyridine are found in Table 1. Figure 1. 2-amino-3-hydroxypyridine 2-Amino-3-hydroxypyridine is commonly used as a component of oxidative hair dyes.2 This ingredient acts as a “coupler” and reacts with a “precursor.” In a typical formulation, a precursor is activated via an oxidant, such as peroxide. The result- ant activated precursor proceeds to couple with a coupler such as 2-amino-3-hydroxypyridine to form an in-situ coupled product that is purported to be the actual dye that colors hair in these types of oxidative hair dyes. Nitrosamine content was not found for 2-amino-3-hydroxypyridine. 2-Amino-3-hydroxypyridine bears a primary aryl amine. While many secondary amines and amides are readily nitrosated to form isolatable nitrosamines and nitrosamides, primary alkyl and aryl amines ultimately yield diazonium salts, instead of nitrosamines. The nitrogen atom of the pyridine core, how- ever, has been shown to be susceptible to nitrosation.3 Of concern in cosmetics is the conversion (nitrosation) of nitrogen bearing ingredients into N-nitroso chemicals that may be carcinogenic. Of the approximately 209 nitrosamines tested, 85% have been shown to produce cancer in laboratory animals.4 Nitrosation can occur under physiologic conditions.5 Depending on the nitrosating agent and the substrate, nitrosation can occur under acidic, neutral, or alkaline conditions. Atmospheric NO 2 may also participate in nitrosation in aqueous solution.6 Accordingly, hair dyes with 2-amino-3-hydroxypyridine should be formulated to avoid the formation of N-nitrosopyridinium compounds. Impurities Potential impurities in 2-amino-3-hydroxypyridine may include 2,3-dihydroxypyridine and 3-hydroxy-2-pyridone.7 Heavy … [kırpıldı — bölüm toplam 7043 karakter]

Acute Toxicity Oral – Non-Human The acute oral toxicity of 2-amino-3-hydroxypyridine in propylene glycol was tested in Wistar rats.14 Three females and 3 males received a single gavage dose of the test substance at 300 mg/kg body weight and 3 females received a single dose at 1000 mg/kg. The rats were observed daily for mortalities and clinical signs of toxicity for 14 days. All 3 rats of the 1000 mg/kg dose group and 1 female in the 300 mg/kg dose group died immediately after dosing. Clinical signs in the 1000 mg/kg dose group included tremor, cramped posture, hunched posture, abnormal gait, salivation and chromodacryorrhea. Females in the 300 mg/kg were observed with the following clinical signs: restless, lethargy, tremor, hunched posture, uncoordinated movements, flat gait, quacking breathing, labored respiration, rales, shallow respiration, piloerection, salivation, chro- modacryorrhea, pale, and ptosis. No clinical signs were observed in the 300 mg/kg dose group males. Surviving animals recovered from the symptoms between days 2 and 7, except for one female experiencing chromodacryorrhea and rales that recovered by day 15. No abnormal weight gain was observed in the males and slight weight loss or reduced body weight gain between days 8 and 15 in the females was not considered significant. At necropsy, the animals that died after the 1000 mg/kg dose had enlarged lungs with many dark red foci. In the female that died following the 300 mg/kg dose, reddish dis- coloration of stomach mucosa was observed. Enlarged mandibular lymph nodes were noted in the males. In this acute oral toxicity study, the median oral LD 50 was greater than 300 mg/kg body weight in male Wistar rats and less than 1000 mg/kg body weight in female Wistar rats.  Distributed for Comment Only -- Do Not Cite or Quote Repeated Dose Toxicity Oral – Non-Human … [kırpıldı — bölüm toplam 17066 karakter]

CIR tentative (2014): The CIR Expert Panel concluded 2-amino-3-hydroxypyridine is safe in the present practices of use and concentration for use in oxidative hair dye formulations.

EPA ToxValDB skin/eye data — endpoint: skin sensitisation: in vivo (LLNA), classification: Not likely to be sensitizing, species: mouse, study: skin sensitization, guideline: according to OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay) according to EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay) according to EPA OPPTS 870.2600 (Skin Sensitisation), year: 2004. Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

EPA ToxValDB skin/eye data — endpoint: skin irritation: in vivo, classification: Studies Indicate No Significant Irritation, species: rabbit, study: skin irritation, guideline: OECD Guideline 404 (Acute Dermal Irritation / Corrosion) according to EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion) according to EPA OPPTS 870.2500 (Acute Dermal Irritation) according to, year: 2004. Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

EPA ToxValDB skin/eye data — endpoint: Skin Irritation, classification: Category 6.3A (Category 2). Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

EPA ToxValDB skin/eye data — endpoint: Eye Irritation, classification: Category 6.4A (Category 2A). Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.