Fluoxetine and carbamazepine are widely prescribed psychotropic drugs, yet few studies have quantified metal(loid) impurities in these medicines, which may pose health risks to patients. This study aimed to determine concentrations of As, Cd, Cr, Cu, Fe, K, Mg, Mn, P, Pb, Se, and Zn in brand, similar, and generic samples of fluoxetine and carbamazepine marketed in Campo Grande, Brazil. Drug samples were purchased from local pharmacies, digested with acid, and analyzed by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). Results showed that arsenic was detected only in fluoxetine samples, with concentrations ranging from 0.068 to 0.217 mg/kg, all below national and international limits. Phosphorus presented the highest levels, especially in fluoxetine, reaching up to 14,000 mg/kg, and up to 93 mg/kg in carbamazepine. Other elements such as Fe (0.07–3.03 mg/kg), Mg (0.21–259 mg/kg), K (up to 45 mg/kg), Se (up to 1.5 mg/kg), and Zn (up to 4.2 mg/kg) were also quantified, while Cd, Cr, Cu, and Pb were below detection limits. The hazard index (HI) exceeded 1 for all carbamazepine samples and for one brand, two similar, and three generic fluoxetine samples, indicating that the intake of these medications may pose potential health concerns. These findings underscore the need for stricter monitoring of metal(loid) impurities in psychotropic drugs to protect patient safety and ensure regulatory compliance.

Lithium carbonate is one of the most prescribed mood stabilizers worldwide and remains the first-line pharmacological treatment for bipolar disorder (BD). Its therapeutic efficacy is well established; however, lithium (Li) has a narrow therapeutic index, and prolonged or excessive intake can cause renal, neurological, or endocrine toxicity. In Brazil and globally, lithium-based formulations are widely commercialized; however, only Brazil adopts a specific regulatory classification distinguishing reference, generic, and similar medicines. Despite its extensive clinical use, studies monitoring the actual Li concentration in pharmaceutical products are extremely scarce. This study quantified Li concentrations in different formulations available in Brazil to evaluate their chemical uniformity, estimated daily intake, and potential health risks. Samples were digested and analyzed using Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). Statistical analysis with the Kruskal–Wallis test revealed significant differences among formulations (p = 0.012), confirming non-uniform Li content. Measured concentrations ranged from 245.47 to 315.24 mg/kg, with generic products showing the highest values. The calculated daily intake (DI) and chronic daily intake (CDI) increased with therapeutic dose (600–1800 mg/day), and higher-dose regimens frequently exceeded the permitted daily exposure (PDE) value for Li established by International Council for Harmonisation Guideline for Elemental Impurities (Revision 2) (ICH Q3D (R2) (0.55 mg/day). Moreover, hazard quotient (HQ) values above 1 in some scenarios indicated potential health risks associated with excessive or long-term Li exposure. As one of the first studies to quantify Li in marketed formulations, this work underscores the need for systematic monitoring and stricter quality control to ensure therapeutic safety.

Lithium carbonate is a cornerstone therapy for bipolar disorder, typically administered long-term, which necessitates strict control of elemental impurities beyond the quantification of the active ingredient. While previous studies focused on lithium concentration and dosing accuracy, this study characterized the unique inorganic signatures and evaluated the toxicological implications of reference, similar, and generic lithium carbonate formulations marketed in Brazil. Seven commercial brands were analyzed by inductively coupled plasma optical emission spectrometry (ICP OES). Elemental concentrations (mg/kg) ranged as follows: As (0.50–0.62), Pb (0.39–0.57), Se (0.80–1.01), Cr (detected in one similar formulation at 0.18), Fe (<LOD–0.86), Mg (8.10–14.65), K (1.18–4.2), Mn (0.072–0.40), and P (24.3–74.4), while Cd, Cu, and Zn were below detection limits. Statistical analysis (p < 0.05) demonstrated significant inter-manufacturer differences, indicating that pharmaceutical equivalence does not imply inorganic identity. Despite this variability, all formulations complied with ICH Q3D (R2), USP , and Brazilian Pharmacopoeia limits. Under maintenance doses of 600–1200 mg/day, daily exposure remained well below Permitted Daily Exposure thresholds; the cumulative Hazard Index was <0.02, and Incremental Lifetime Cancer Risk (5.46 to 6.80 × 10⁻⁶) was within safe levels. These findings confirm that while distinct elemental signatures exist, the medications are toxicologically safe for chronic therapy.