- 1.
Brown, P.N.; Lund, J.A.; Murch, S.J. A botanical, phytochemical and ethnomedicinal review of the genus Mitragyna korth: Implications for products sold as kratom. J. Ethnopharmacol. 2017, 202, 302–325.
- 2.
Annuwar, N.A.K.; Azlam, U.K.; Mediani, A; et al. An insight review on the neuropharmacological effects, mechanisms of action, pharmacokinetics and toxicity of mitragynine. Biomed. Pharmacother. 2024, 171, 116134.
- 3.
Alford, A.S.; Moreno, H.L.; Benjamin, M.M.; et al. Exploring the therapeutic potential of mitragynine and corynoxeine: Kratom-derived indole and oxindole alkaloids for pain management. Pharmaceuticals 2025, 18, 222.
- 4.
Das, J. Kratom alkaloids for the treatment of alcohol use disorder. ACS Chem. Neurosci. 2024, 15, 4352–4359.
- 5.
Garza-Garcia, J.J.O.; Qu, Y. Chemical, pharmacological properties and biosynthesis of opioid mitragynine in Mitragyna speciosa (kratom). Curr. Opin. Plant Biol. 2024, 81, 102600.
- 6.
Begum, T.; Arzmi, M.H.; Khatib, A.; et al. A review on Mitragyna speciosa (Rubiaceae) as a prominent medicinal plant based on ethnobotany, phytochemistry and pharmacological activities. Nat. Prod. Res. 2024, 39, 1636–1652.
- 7.
Ernawati, T.; Hermawan, F.; Kusumaningrum, S. A review on isolation, characterization, biosynthesis, synthesis, modification, pharmacological activities and toxicology of mitragynine. Gazi Univ. J. Sci. 2024, 37, 1654–1672.
- 8.
Bachu, A.K.; Singal, P.; Griffin, B.; et al. Kratom use and mental health: A systematic literature review and case example. J. Addictive Dis. 2024, 42, 301–312.
- 9.
Karunakaran, T.; Ngew, K.Z.; Zailan, A.A.D.; et al. The chemical and pharmacological properties of mitragynine and its diastereomers: An insight review. Front. Pharmacol. 2022, 13, 805986.
- 10.
Harun, N.; Kamaruzzaman, N.A.; Sofian, Z.M.; et al. Mini review: Potential therapeutic values of mitragynine as an opioid substitution therapy. Neurosci. Lett. 2022, 773, 136500.
- 11.
Sengnon, N.; Vonghirundecha, P.; Chaichan, W.; et al. Seasonal and geographic variation in alkaloid content of kratom (Mitragyna speciosa (Korth.) Havil.) from Thailand. Plants 2023, 12, 949.
- 12.
Leksungnoen, N.; Andriyas, T.; Ngernsaengsaruay, C.; et al. Variations in mitragynine content in the naturally growing Kratom (Mitragyna speciosa) population of Thailand. Front. Plant Sci. 2022, 13, 1028547.
- 13.
Warner, M.L.; Kaufman, N.C.; Grundmann, O. The pharmacology and toxicology of kratom: From traditional herb to drug of abuse. Int. J. Legal Med. 2016, 130, 127–138.
- 14.
Leksungnoen, N.; Andriyas, T.; Tansawat, R.; et al. Higher accumulation of mitragynine in Mitragyna speciosa (kratom) leaves affected by insect attack. PLoS ONE 2025, 20, e0320941.
- 15.
Leksungnoen, N.; Andriyas, T.; Ku-Or, Y.; et al. The effect of light intensity and polyethylene-glycol-induced water stress on the growth, mitragynine accumulation, and total alkaloid content of kratom (Mitragyna speciosa). Horticulture 2025, 11, 272.
- 16.
Sudmoon, R.; Tanee, T.; Wonok, W.; et al. Discovery of rhynchophylline and mitraphylline in two Thai Mitragyna species and the investigation of their biological activity via opioid gene expression analysis. Sci. Rep. 2025, 15, 5865.
- 17.
Ramanathan, S.; Parthasarathy, S.; Murugaiyah, V.; et al. Understanding the physicochemical properties of mitragynine, a principal alkaloid of Mitragyna speciosa, for preclinical evaluation. Molecules 2015, 20, 4915–4927.
- 18.
Azhar, S.N.A.S.; Ashari, S.E.; Tan, J.K.; et al. Screening and selection of formulation components of nanostructured lipid carriers system for Mitragyna speciosa (Korth). Havil drug delivery. Ind. Crops Prod. 2023, 198, 116668.
- 19.
Anantaworasakul, P.; Preedalikit, W.; Anantaworasakul, P.; et al. Phytochemical characterization, bioactivities and nanoparticle-based topical gel formulation development from four Mitragyna speciosa varieties. Gels 2025, 11, 494.
- 20.
Zhao, S.M.; Zhao, H.; Zuo, J.Y.; et al. Evaluation of drug permeability across Ex vivo nasal mucosa: A simulation-based approach to minimize thickness-related variability. J. Drug Delivery Sci. Technol. 2025, 108, 106959.
- 21.
Tabboon, P.; Limpongsa, E.; Tuntiyasawasdikul, S.; et al. Screening the potential of pharmaceutical liquids on enhancing dissolution, intestinal permeation, and stability of Mitragyna speciosa bioactive for peroral delivery systems. Ind. Crops Prod. 2025, 225, 120525.
- 22.
Thepthong, P.; Srirat, S.; Hiranrat, W.; et al. Development of chitosan-based microencapsulation system for Mitragyna speciosa alkaloids: A novel approach for alzheimer's disease treatment. J. Pharm. Innov. 2025, 20, 58.
- 23.
Singh, M.N.; Hemant, K.S.Y.; Ram, M.; et al. Microencapsulation: A promising technique for controlled frug delivery. Research in Pharmaceutical Sciences 2010, 5, 65–77.
- 24.
Tomaro-Duchesneau, C.; Saha, S.; Malhotra, M.; et al. Microencapsulation for the therapeutic delivery of drugs, live mammalian and bacterial cells, and other biopharmaceutics: Current status and future directions. J. Pharm. 2012, 2013, 103527.
- 25.
Zhao, L.; Chen, J.; Bai, B.; et al. Topical drug delivery strategies for enhancing drug effectiveness by skin barriers, drug delivery systems and individualized dosing. Front. Pharmacol. 2024, 14, 1333986.
- 26.
Roberts, M.S.; Cheruvu, H.S.; Mangion, S.E.; et al. Topical drug delivery: History, percutaneous absorption, and product development. Adv. Drug Delivery Rev. 2021, 177, 113929.
- 27.
Tuntiyasawasdikul, S.; Junlatat, J.; Tabboon, P.; et al. Mitragyna speciosa ethanolic extract: Extraction, anti-inflammatory, cytotoxicity, and transdermal delivery assessments. Ind. Crops Prod. 2024, 208, 117909.
- 28.
Djupesland, P.G. Nasal drug delivery devices: Characteristics and performance in a clinical perspective – A review. Drug Delivery Transl. Res. 2013, 3, 42–62.
- 29.
Sood, A.; Panchagnula, R. Peroral route: An opportunity for protein and peptide drug delivery. Chem. Rev. 2001, 101, 3275–3303.
- 30.
Khan, S.; Sharma, A.; Jain, V. An overview of nanostructured lipid carriers and its application in drug delivery through different routes. Adv. Pharm. Bull. 2022, 13, 446–460.
- 31.
Chauhan, I.; Yasir, M.; Verma, M.; et al. Nanostructured lipid carriers: A groundbreaking approach for transdermal drug delivery. Asvanced Pharm. Bull. 2020, 10, 150–165.
- 32.
Matra, M.; Phupaboon, S.; Totakul, P.; et al. Microencapsulation of Mitragyna leaf extracts to be used as a bioactive compound source to enhance in vitro fermentation characteristics and microbial dynamics. Anim. Biosci. 2023, 37, 74–83.
- 33.
Sim, Y.S.; Chong, Z.Y.; Azizi, K.; et al. Development and validation of a gradient HPLC-UV method for mitragynine following in vitro skin permeation studies. J. Chromatogr. B 2022, 1204, 123316.
- 34.
Peace, M.R.; Smith, M.E.; Poklis, J.L. The analysis of commercially available natural products recommended for use in electronic cigarettes. Rapid Commun. Mass Spectrom. 2020, 34, e8771.