{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T12:04:35Z","timestamp":1784721875998,"version":"3.55.0"},"reference-count":33,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T00:00:00Z","timestamp":1784505600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxics"],"abstract":"<jats:p>Buspirone is an anxiolytic drug used for the treatment of generalized anxiety disorder. Even though it was patented 50 years ago, it is still among the top three most commonly prescribed anti-anxiety medications in the US. Its fate in the environment and ecotoxic effects have not yet been assessed. In this study, the direct and indirect (with humic acids) photodegradation of buspirone was assessed using the SunTest CPS+ sunlight simulator in two radiation ranges: 280\u2013800 nm and 290\u2013800 nm. The concentration of buspirone and the formation of photoproducts were assessed using liquid chromatography with a diode array and mass spectrometry detector. Toxicity was assessed using biotests with luminescent bacteria and protozoan Spirostomum ambiguum, as well as in silico analyses on daphnia, fish, and protozoan Tetrahymena pyriformis. Buspirone was degraded by sunlight. Expanding the radiation range from 290 to 280 nm accelerated degradation. Humic acids, however, had no effect in either case. The structures of 24 phototransformation products have been proposed. Neither buspirone nor most of its photodegradation products were toxic. Only two derivatives had a calculated 96h-LC50 value for fish below 1 mg L\u22121. The obtained results indicate a low environmental risk of buspirone.<\/jats:p>","DOI":"10.3390\/toxics14070633","type":"journal-article","created":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T16:19:27Z","timestamp":1784564367000},"page":"633","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Photodegradation of Buspirone: Ecotoxicological Assessment and Identification of Photoproducts"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4945-3687","authenticated-orcid":false,"given":"Grzegorz","family":"Na\u0142\u0119cz-Jawecki","sequence":"first","affiliation":[{"name":"Department of Toxicology and Food Science, Medical University of Warsaw, Banacha 1 Str., 02-097 Warszawa, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marta","family":"Kozak","sequence":"additional","affiliation":[{"name":"Department of Toxicology and Food Science, Medical University of Warsaw, Banacha 1 Str., 02-097 Warszawa, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2567-4453","authenticated-orcid":false,"given":"Joanna","family":"Giebu\u0142towicz","sequence":"additional","affiliation":[{"name":"Department of Drug Chemistry, Pharmaceutical and Biomedical Analysis, Medical University of Warsaw, Banacha 1 Str., 02-097 Warszawa, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Milena","family":"Wawryniuk","sequence":"additional","affiliation":[{"name":"Department of Toxicology and Food Science, Medical University of Warsaw, Banacha 1 Str., 02-097 Warszawa, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8320-1200","authenticated-orcid":false,"given":"Agata","family":"Drobniewska","sequence":"additional","affiliation":[{"name":"Department of Toxicology and Food Science, Medical University of Warsaw, Banacha 1 Str., 02-097 Warszawa, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,20]]},"reference":[{"key":"ref_1","unstructured":"Kane, S.P. (2023). ClinCalc DrugStats: Most Commonly Prescribed Medications in 2023, ClinCalc. Available online: https:\/\/clincalc.com\/blog\/2025\/08\/clincalc-drugstats-most-commonly-prescribed-medications-in-2023\/."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.jpba.2004.01.001","article-title":"The photocatalytic process as a tool to identify metabolitic products formed from dopant substances: The case of buspirone","volume":"35","author":"Calza","year":"2004","journal-title":"J. Pharm. Biomed. Anal."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"402","DOI":"10.1002\/(SICI)1096-9888(200003)35:3<402::AID-JMS950>3.0.CO;2-L","article-title":"Equine metabolism of buspirone studied by high-performance liquid chromatography\/mass spectrometry","volume":"35","author":"Stanley","year":"2000","journal-title":"J. Mass Spectrom."},{"key":"ref_4","first-page":"37","article-title":"Acute exposure to waterborne psychoactive drugs attract zebrafish","volume":"179","author":"Abreu","year":"2016","journal-title":"Comp. Biochem. Physiol. C"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"480","DOI":"10.1016\/j.pbb.2011.04.021","article-title":"Effects of anxiolytics in zebrafish: Similarities and differences between benzodiazepines, buspirone and ethanol","volume":"99","author":"Gebauer","year":"2011","journal-title":"Pharmacol. Biochem. Behav."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"6097","DOI":"10.1016\/j.watres.2011.09.008","article-title":"Photodegradation of psychiatric pharmaceuticals in aquatic environments\u2014Kinetics and photodegradation products","volume":"45","author":"Calisto","year":"2011","journal-title":"Water Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1","DOI":"10.32725\/jab.2024.007","article-title":"Selected widely prescribed pharmaceuticals: Toxicity of the drugs and the products of their photochemical degradation to aquatic organisms","volume":"22","author":"Klementova","year":"2024","journal-title":"J. Appl. Biomed."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1152","DOI":"10.1007\/s11356-016-7727-5","article-title":"Studies on photodegradation process of psychotropic drugs: A review","volume":"24","year":"2017","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Chojnacka, J., Giebu\u0142towicz, J., Choi\u0144ska, N., Drobniewska, A., and Na\u0142\u0119cz-Jawecki, G. (2023). Do Microplastics Affect the Photodegradation of Duloxetine and Its Phototoxicity to Protozoan Spirostomum ambiguum (M\u00fcller, 1786) Ehrenberg, 1835?. Water, 15.","DOI":"10.3390\/w15223890"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"4733","DOI":"10.1007\/s11356-025-36000-7","article-title":"Environmental and toxicological aspects of sulfamethoxazole photodegradation in the presence of oxidizing agents","volume":"32","author":"Gackowska","year":"2025","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"111680","DOI":"10.1016\/j.envres.2021.111680","article-title":"Ecotoxicity and photodegradation of Montelukast (a drug to treat asthma) in water","volume":"202","author":"Siciliano","year":"2021","journal-title":"Environ. Res."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"462","DOI":"10.1093\/chromsci\/37.12.462","article-title":"Stability-Indicating High-Performance Liquid Chromatographic Assay of Buspirone HCl","volume":"37","author":"Khedr","year":"1999","journal-title":"J. Chromatogr. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"11214","DOI":"10.1021\/acs.analchem.7b01638","article-title":"TiO2 Photocatalysis\u2212DESI-MS Rotating Array Platform for High-Throughput Investigation of Oxidation Reactions","volume":"89","author":"Ruokolainen","year":"2017","journal-title":"Anal. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1002\/tox.20023","article-title":"Spirotox\u2014Spirostomum ambiguum acute toxicity test\u201410 years of experience","volume":"19","year":"2004","journal-title":"Environ. Toxicol."},{"key":"ref_15","unstructured":"EPA (1998). OPPTS 835.5270 Indirect Photolysis Screening Test. Fate, Transport and Transformation Test Guidelines, 712-C-98-099."},{"key":"ref_16","unstructured":"(2007). Water Quality\u2014Determination of the Inhibitory Effect of Water Samples on the Light Emission of Vibrio fischeri (Luminescent Bacteria Test). Part 3: Method Using Freeze-Dried Bacteria (Standard No. ISO 11348-3:2007)."},{"key":"ref_17","unstructured":"EMA (2014). Guideline on the Environmental Risk Assessment of Medicinal Products for Human Use, European Medicines Agency. EMEA\/CHMP\/SWP\/4447\/00 Rev. 1 -Corr."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"542","DOI":"10.1021\/acsestwater.0c00081","article-title":"Occurrence and fate of psychiatric pharmaceuticals in wastewater treatment plants in Hong Kong: Enantiomeric Profiling and preliminary risk assessment","volume":"1","author":"Wu","year":"2021","journal-title":"ACS EST Water"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1016\/j.toxlet.2007.10.012","article-title":"Human pharmaceuticals in surface waters. Implementation of a prioritization methodology and application to the French situation","volume":"176","author":"Besse","year":"2008","journal-title":"Toxicol. Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"27041","DOI":"10.1007\/s11356-022-23667-5","article-title":"Occurrence and removal of psychiatric pharmaceuticals in the Tehran South municipal wastewater treatment plant","volume":"30","author":"Golbaz","year":"2023","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"107318","DOI":"10.1016\/j.ntt.2023.107318","article-title":"Exposure to the pharmaceutical buspirone alters locomotor activity, anxiety-related behaviors, and transcripts related to serotonin signaling in larval zebrafish (Danio rerio)","volume":"101","author":"Biju","year":"2024","journal-title":"Neurotox. Teratol."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Abozaid, A., and Gerlai, R. (2022). Behavioral Effects of Buspirone in Juvenile Zebrafish of Two Different Genetic Backgrounds. Toxics, 10.","DOI":"10.3390\/toxics10010022"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1007\/s10646-007-0171-z","article-title":"Photodegradation and phototoxicity of thioridazine and chlorpromazine evaluated with chemical analysis and aquatic organisms","volume":"17","author":"Hajnas","year":"2008","journal-title":"Ecotoxicology"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Na\u0142\u0119cz-Jawecki, G., Wawryniuk, M., Giebu\u0142towicz, J., Olkowski, A., and Drobniewska, A. (2020). Influence of selected antidepressants on the ciliated protozoan Spirostomum ambiguum: Toxicity, bioaccumulation, and biotransformation products. Molecules, 25.","DOI":"10.3390\/molecules25071476"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1002\/tox.2530060105","article-title":"The relative sensitivity of Microtox\u00ae daphnid, rainbow trout and fathead minnow acute lethality tests","volume":"6","author":"Munkittrick","year":"1991","journal-title":"Environ. Toxicol. Water Qual."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"672","DOI":"10.1039\/c3em00615h","article-title":"A critical assessment of the photodegradation of pharmaceuticals in aquatic environments: Defining our current understanding and identifying knowledge gaps","volume":"16","author":"Challis","year":"2014","journal-title":"Environ. Sci. Process. Impacts"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2399","DOI":"10.1021\/es9610646","article-title":"Role of quinone intermediates as electron shuttles in Fenton and photoassisted Fenton oxidation of aromatic compounds","volume":"31","author":"Chen","year":"1997","journal-title":"Environ. Sci. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1829","DOI":"10.1007\/s43630-024-00633-3","article-title":"Cefadroxil photodegradation processes sensitized by natural pigments: Mechanistic aspects and impact on the antimicrobial function","volume":"23","author":"Urquiza","year":"2024","journal-title":"Photochem. Photobiol. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1687","DOI":"10.1007\/s43630-024-00621-7","article-title":"Photodegradation of tylosin tartrate by advanced oxidation processes","volume":"23","author":"Mundi","year":"2024","journal-title":"Photochem. Photobiol. Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2044","DOI":"10.1007\/s11356-019-06676-9","article-title":"Effect of dissolved organic matters and inorganic ions on TiO2 photocatalysis of diclofenac: Mechanistic study and degradation pathways","volume":"27","author":"Guo","year":"2020","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1017","DOI":"10.1002\/jms.876","article-title":"Hybrid triple quadrupole-linear ion trap mass spectrometry in fragmentation mechanism studies: Application to structure elucidation of buspirone and one of its metabolites","volume":"40","author":"Zhang","year":"2005","journal-title":"J. Mass Spectrom."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"562","DOI":"10.1016\/j.trac.2009.02.006","article-title":"Complementary mass spectrometry and bioassay for evaluating pharmaceutical-transformation products in treatment of drinking water and wastewater","volume":"28","year":"2009","journal-title":"Trends Anal. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Baran, W., Madej-Knysak, D., and Adamek, E. (2026). Environmental impact of fluoroquinolones and their photocatalytic transformation products: Degradation with activated sludge and in surface waters, change in antimicrobial activity and ecotoxicity. Int. J. Mol. Sci., 27.","DOI":"10.3390\/ijms27052099"}],"container-title":["Toxics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2305-6304\/14\/7\/633\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T11:44:20Z","timestamp":1784720660000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2305-6304\/14\/7\/633"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,20]]},"references-count":33,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["toxics14070633"],"URL":"https:\/\/doi.org\/10.3390\/toxics14070633","relation":{},"ISSN":["2305-6304"],"issn-type":[{"value":"2305-6304","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,20]]}}}