{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T20:28:53Z","timestamp":1777667333216,"version":"3.51.4"},"reference-count":35,"publisher":"SAGE Publications","issue":"5","license":[{"start":{"date-parts":[[1998,5,1]],"date-time":"1998-05-01T00:00:00Z","timestamp":893980800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Hum Exp Toxicol"],"published-print":{"date-parts":[[1998,5]]},"abstract":"<jats:p>1-Methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) induces symptoms                 indistinguishable from those of Parkinson's disease. It selectively destroys                 dopaminergic neurons in the substantia nigra and the globus pallidus. Death of these                 same neurons is apparently the cause of idiopathic Parkinson's disease. As                 phenyl-1,2,3,6 tetrahydropyridine is a commonly encountered subunit in heterocyclic                 drugs and because MPTP was found as a minor impurity in early batches of a candidate                 drug at Merck KGaA, it may be assumed that MPTP will also be present as an as yet                 undiscovered minor impurity in various existing drugs. A neurotoxicity risk                 assessment on MPTP has been conducted to define the risk of MPTP as an impurity in                 drugs that are used orally. This risk assessment has shown that compounds containing                 less than 5.0 p.p.m. MPTP administered orally will not cause a neurotoxicological                 health risk to patients treated with such a drug.<\/jats:p>","DOI":"10.1177\/096032719801700514","type":"journal-article","created":{"date-parts":[[2017,1,15]],"date-time":"2017-01-15T13:47:36Z","timestamp":1484488056000},"page":"283-293","source":"Crossref","is-referenced-by-count":5,"title":["Neurotoxicity risk assessment of MPTP                 (N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) as a synthetic impurity of drugs"],"prefix":"10.1177","volume":"17","author":[{"given":"Peter Juergen","family":"Kramer","sequence":"first","affiliation":[{"name":"Institute of Toxicology, Merck KGaA, D-64271 Darmstadt, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"John","family":"Caldwell","sequence":"additional","affiliation":[{"name":"Division of Biomedical Sciences, Imperial College School of Medicine,                         London W2 1PG, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andreas","family":"Hofmann","sequence":"additional","affiliation":[{"name":"Institute of Toxicology, Merck KGaA, D-64271 Darmstadt, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peter","family":"Tempel","sequence":"additional","affiliation":[{"name":"Institute of Toxicology, Merck KGaA, D-64271 Darmstadt, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Guenter","family":"Weisse","sequence":"additional","affiliation":[{"name":"Institute of Toxicology, Merck KGaA, D-64271 Darmstadt, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[1998,5]]},"reference":[{"key":"e_1_2_1_1_1","first-page":"285","article-title":"A model of chronic neurotoxicity: long-term retention of the neurotoxin                         1-methyl-4- phenylpyridinium (MPP+) within catecholaminergic neurons","volume":"12","author":"Johannessen JN.","year":"1991","unstructured":"Johannessen JN. 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