{"id":"3f8ac30a-f73c-57ed-86fd-4940f65dbce7","stable_key":"f2ec2007-88ff-5a96-a73b-8b5085e9cea9:mbz-wrong-form-reaches-market","predicate":"is_component_of","statement":"Of four raw materials of mebendazole examined, three were polymorph C and the other was polymorph A or a mixture of forms A and B, with X-ray powder diffractometry and infrared spectroscopy indicating form B while the much slower powder dissolution suggested polymorph A; the literature prescribes use of polymorph C pharmaceutically, generic manufacturers should be aware that forms other than C are still available on the market, and all four mebendazole tablets then available in South Africa contained polymorph C.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"59a1f6ab-5a93-56c6-9f0c-711baab67f4f","mechanism_event_label":"The inactive form is still sold as raw material, and the tests used to tell the forms apart do not always agree.","subject":{"id":"c035837e-301e-5643-8242-c1483f7f423d","slug":"mebendazole-polymorph-a","display_name":"Mebendazole polymorph A","entity_type_key":"chemical_species"},"object":{"id":"bd95c09d-7613-5fed-b54a-b918e25f6551","slug":"aqueous-solubility","display_name":"Aqueous solubility and dissolution rate of the solid drug","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"59a1f6ab-5a93-56c6-9f0c-711baab67f4f","stable_key":"f2ec2007-88ff-5a96-a73b-8b5085e9cea9:mbz-wrong-form-reaches-market-event","event_type":"observed_intervention","label":"The inactive form is still sold as raw material, and the tests used to tell the forms apart do not always agree.","description":"Of four raw materials of mebendazole examined, three were polymorph C and the other was polymorph A or a mixture of forms A and B, with X-ray powder diffractometry and infrared spectroscopy indicating form B while the much slower powder dissolution suggested polymorph A; the literature prescribes use of polymorph C pharmaceutically, generic manufacturers should be aware that forms other than C are still available on the market, and all four mebendazole tablets then available in South Africa contained polymorph C.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"1f996273-d9f1-5c5c-acd8-ec168cfebd64","slug":"mebendazole-polymorph-c","display_name":"Mebendazole polymorph C","entity_type_key":"chemical_species"},"role":"prescribed_form","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"083bffe6-7974-58f0-ad9f-9c1cd7a5193f","slug":"mebendazole-polymorph-b","display_name":"Mebendazole polymorph B","entity_type_key":"chemical_species"},"role":"candidate_form","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"d21e579a-6e2c-5edc-8c44-b1a1f0269e5a","slug":"tablet-dissolution","display_name":"Tablet dissolution against USP and FDA specifications","entity_type_key":"cellular_process"},"role":"discriminating_measure","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"c035837e-301e-5643-8242-c1483f7f423d","slug":"mebendazole-polymorph-a","display_name":"Mebendazole polymorph A","entity_type_key":"chemical_species"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"bd95c09d-7613-5fed-b54a-b918e25f6551","slug":"aqueous-solubility","display_name":"Aqueous solubility and dissolution rate of the solid drug","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/mebendazole-research/9876612.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"c0cb5ad093307edd2cbaee474418c3086cd524c606eaddd1cae7186ed962fd26\", \"start_char\": 0, \"end_char\": 666, \"text_sha256\": \"c0cb5ad093307edd2cbaee474418c3086cd524c606eaddd1cae7186ed962fd26\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Preformulation analysis of four mebendazole raw materials and four marketed tablets","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"X-ray powder diffractometry, infrared spectroscopy and powder dissolution","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"A small survey in one country at one time. It also shows the analytical methods disagreeing with each other on one sample, which is recorded.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms.","comparator":null,"unit":null,"notes":"","entity":{"slug":"mebendazole","display_name":"Mebendazole","entity_type_key":"drug"}},{"dimension":"organism","value_text":"Pharmaceutical product","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The inactive form is still sold as raw material, and the tests used to tell the forms apart do not always agree.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[mbz-p9876612] Identification of the mebendazole polymorphic form present in raw materials and tablets available in South Africa. (1998). https://pubmed.ncbi.nlm.nih.gov/9876612/ DOI: 10.3109/03639049809085647","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Raw material and tablets","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"2803b633-57ec-5c78-b174-6c9b05624356","evidence_kind":"source_excerpt","locator":"Lines 394-405","start_line":394,"end_line":405,"excerpt":"### mbz-wrong-form-reaches-market\nOf four raw materials of mebendazole examined, three were polymorph C and the other was polymorph A or a mixture of forms A and B, with X-ray powder diffractometry and infrared spectroscopy indicating form B while the much slower powder dissolution suggested polymorph A; the literature prescribes use of polymorph C pharmaceutically, generic manufacturers should be aware that forms other than C are still available on the market, and all four mebendazole tablets then available in South Africa contained polymorph C.\nCondition category: normal\nnutrient_topic: Mebendazole research collection; topical membership is not evidence of a direct clinical effect, and mebendazole is recorded separately from albendazole, from the benzimidazole class and from its own crystal forms.\nplain_language: The inactive form is still sold as raw material, and the tests used to tell the forms apart do not always agree.\norganism: Pharmaceutical product\ntissue_or_cell_type: Raw material and tablets\nexperimental_model: Preformulation analysis of four mebendazole raw materials and four marketed tablets\nlimitations: A small survey in one country at one time. It also shows the analytical methods disagreeing with each other on one sample, which is recorded.\nexposure: X-ray powder diffractometry, infrared spectroscopy and powder dissolution\nevidence_span: {\"source_cache\": \"artifacts/mebendazole-research/9876612.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"c0cb5ad093307edd2cbaee474418c3086cd524c606eaddd1cae7186ed962fd26\", \"start_char\": 0, \"end_char\": 666, \"text_sha256\": \"c0cb5ad093307edd2cbaee474418c3086cd524c606eaddd1cae7186ed962fd26\"}\n[mbz-p9876612] Identification of the mebendazole polymorphic form present in raw materials and tablets available in South Africa. (1998). https://pubmed.ncbi.nlm.nih.gov/9876612/ DOI: 10.3109/03639049809085647","model_system":"Preformulation analysis of four mebendazole raw materials and four marketed tablets","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [mbz-p9876612] Identification of the mebendazole polymorphic form present in raw materials and tablets available in South Africa. (1998). https://pubmed.ncbi.nlm.nih.gov/9876612/ DOI: 10.3109/03639049809085647","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"06104773-03d0-5e5c-b9da-eb484e7be657","stable_key":"import-f2ec2007-88ff-5a96-a73b-8b5085e9cea9","title":"Mebendazole: the tubulin it binds, why that is selective, the crystal form that decides whether any of it works, and the off-target that became an oncology programme (2026-09-22)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"58b652636677e5033fd1dd555744485fcef18f21a97dcf68723fe072b656f413","revision_id":"a2cd9c22-0549-52ca-a653-8a0c2362ec85","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}