{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,19]],"date-time":"2026-09-19T18:23:47Z","timestamp":1789842227030,"version":"4.0.1"},"reference-count":36,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2023,10,12]],"date-time":"2023-10-12T00:00:00Z","timestamp":1697068800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Croatian Science Foundation","award":["UIP-2019-04-8461"],"award-info":[{"award-number":["UIP-2019-04-8461"]}]},{"name":"Croatian Science Foundation","award":["DOK-2021-02-4995"],"award-info":[{"award-number":["DOK-2021-02-4995"]}]},{"name":"Croatian Science Foundation","award":["KK.01.1.1.02.0021"],"award-info":[{"award-number":["KK.01.1.1.02.0021"]}]},{"DOI":"10.13039\/501100008530","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["UIP-2019-04-8461"],"award-info":[{"award-number":["UIP-2019-04-8461"]}],"id":[{"id":"10.13039\/501100008530","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008530","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["DOK-2021-02-4995"],"award-info":[{"award-number":["DOK-2021-02-4995"]}],"id":[{"id":"10.13039\/501100008530","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008530","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["KK.01.1.1.02.0021"],"award-info":[{"award-number":["KK.01.1.1.02.0021"]}],"id":[{"id":"10.13039\/501100008530","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pharmaceuticals"],"abstract":"<jats:p>In the development of bioanalytical LC-MS methods for the determination of drugs in plasma samples in a clinical setting, adequate sample preparation is of utmost importance. The main goals are to achieve the selective extraction of the analytes of interest and attain thorough matrix removal while retaining acceptable ecological properties, cost-effectiveness, and high throughput. Solid-phase extraction (SPE) offers a versatile range of options, from the selection of an appropriate sorbent to the optimisation of the washing and elution conditions. In this work, the first SPE method for the simultaneous extraction of six anticancer drugs used in novel therapeutic combinations for advanced breast cancer treatment\u2014palbociclib, ribociclib, abemaciclib, anastrozole, letrozole, and fulvestrant\u2014was developed. The following sorbent chemistries were tested: octylsilyl (C8), octadecylsilyl (C18), hydrophilic\u2013lipophilic balance (HLB), mixed-mode cation-exchange (MCX and X-C), and mixed-mode weak cation-exchange (WCX), with different corresponding elution solvents. The samples were analysed using LC-MS\/MS, with a phenyl column (150 \u00d7 4.6 mm, 2.5 \u03bcm). The best extraction recoveries (\u226592.3%) of all analytes were obtained with the C8 phase, using methanol as the elution solvent. The optimised method was validated in the clinically relevant ranges, showing adequate precision (inter-day RSD \u2264 14.3%) and accuracy (inter-day bias \u221212.7\u201313.5%). Finally, its applicability was successfully proven by the analysis of samples from breast cancer patients.<\/jats:p>","DOI":"10.3390\/ph16101445","type":"journal-article","created":{"date-parts":[[2023,10,12]],"date-time":"2023-10-12T03:07:47Z","timestamp":1697080067000},"page":"1445","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Optimisation of Solid-Phase Extraction and LC-MS\/MS Analysis of Six Breast Cancer Drugs in Patient Plasma Samples"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4786-5859","authenticated-orcid":false,"given":"Lu","family":"Turkovi\u0107","sequence":"first","affiliation":[{"name":"Department of Pharmaceutical Analysis, Faculty of Pharmacy and Biochemistry, University of Zagreb, Ante Kovacica 1, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7689-7078","authenticated-orcid":false,"given":"Dragana","family":"Mutavd\u017ei\u0107 Pavlovi\u0107","sequence":"additional","affiliation":[{"name":"Department of Analytical Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulicev trg 20, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2571-2461","authenticated-orcid":false,"given":"Zvonimir","family":"Mlinari\u0107","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Analysis, Faculty of Pharmacy and Biochemistry, University of Zagreb, Ante Kovacica 1, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anamarija","family":"Skenderovi\u0107","sequence":"additional","affiliation":[{"name":"GxR&D Analytics Zagreb, Global R&D, Teva Pharmaceuticals, Prilaz Baruna Filipovica 25, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tajana","family":"Silovski","sequence":"additional","affiliation":[{"name":"Department of Oncology, University Hospital Centre Zagreb, Kispaticeva 12, 10000 Zagreb, Croatia"},{"name":"School of Medicine, University of Zagreb, Salata 3, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miranda","family":"Serti\u0107","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Analysis, Faculty of Pharmacy and Biochemistry, University of Zagreb, Ante Kovacica 1, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,10,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1055","DOI":"10.1055\/a-1880-0087","article-title":"Implementation of CDK4\/6 Inhibitors and its Influence on the Treatment Landscape of Advanced Breast Cancer Patients\u2014Data from the Real-World Registry PRAEGNANT","volume":"82","author":"Engler","year":"2022","journal-title":"Geburtshilfe Frauenheilkd."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1007\/s00228-020-03014-8","article-title":"Therapeutic drug monitoring of oral targeted antineoplastic drugs","volume":"77","author":"Groenland","year":"2021","journal-title":"Eur. 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