Gerlinde Rusu

Growing interest in waste valorization and sustainable cleaning products motivated the development and characterization of an eco-friendly powder detergent based on soap derived from waste cooking oil and enriched with juniper essential oil. Waste sunflower oil was pretreated and, together with coconut oil, subjected to cold saponification; the resulting soap base was incorporated at 30% into a detergent formulated with sodium carbonate, sodium bicarbonate, sodium percarbonate and natural zeolite. The raw materials—waste sunflower oil, coconut oil, clinoptilolite and juniper essential oil—were characterized using physicochemical analyses: DSC for coconut oil and Raman spectroscopy for oils, XRF for zeolite, and physicochemical analysis and GC-FID for the essential oil. The soap exhibited pH 9.93, 14.8% moisture, 24 cm foam capacity, and a 3.0 g/min dissolution rate, versus pH 9.33, 10.5% moisture, 12 cm foam capacity, and 1.0 g/min dissolution rate for the detergent. In vitro antibacterial activity was assessed against Escherichia coli and Staphylococcus aureus by agar well diffusion. At 500 mg/mL, inhibition zones reached 8.53 and 17.00 mm for the soap and 7.47 and 15.03 mm for the detergent. Two-way ANOVA confirmed significant effects of sample type and concentration (p < 0.001), with the strain being the dominant source of variation (η²_p = 0.983); both products reached 71.0–87.7% of a commercial reference and were more effective against S. aureus. Antibacterial activity decreased significantly with decreasing concentration (p < 0.001 for all pairwise comparisons), while both formulations showed greater efficacy against S. aureus than against E. coli. The results demonstrate the potential for valorizing waste cooking oil into functional cleaning products and highlight the possibility of contribution of juniper essential oil to the antimicrobial performance of the formulations, supporting the development of sustainable and environmentally compatible detergent products within a circular economy approach.

The honey samples analysed in this study were obtained from a private producer located in Olt County who requested a qualitative characterization of his products depending on honey sources. The first stage of the investigation involved key physicochemical parameters: moisture content, free and total acidity, initial and total invert sugars, sucrose levels, and the presence of hydroxymethylfurfural (HMF) and metallic elements. Differential Scanning Calorimetry (DSC) was additionally used to characterize the thermal properties of the samples. The final part of the study examines the rheological behavior of four honey varieties under different temperature conditions, providing insights into their flow characteristics and structural stability. All the obtained values fall within the ranges established by European regulations, except for Pb; the exceedances reflect the influence of anthropogenic factors in the mentioned region.

This study examines how manufacturer-specific additive formulations used to obtain nominally identical black PLA filaments influence the thermal, mechanical, and tribological performance of FDM-printed parts. Five commercial filaments were analyzed under identical processing conditions using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tensile testing, pin-on-disc measurements, and stereomicroscopy. The filaments exhibited substantial compositional variability, with total additive contents ranging from 2.08 wt.% to 27.82 wt.%. One filament (M5) contained a significant fraction of inorganic fillers, confirmed by SEM/EDX as Ca-, Na- and Mg-based oxides and silicates, identifying it as a PLA-based composite despite being marketed as standard PLA. These differences strongly affected thermal behavior (Tg, Tcc, Tm) and translated directly into the performance of the printed parts. Ultimate tensile strength varied by 88.91% across all filaments (19.38–36.61 MPa), but only by 13% among the four conventional PLA filaments (M1–M4). Tribological performance differed markedly: mean coefficients of friction ranged from 0.246 (M3) to 0.368 (M2), a spread of approximately 50%, with wear-track morphologies reflecting the frictional response. Overall, the results show that PLA filaments cannot be treated as interchangeable materials. Greater transparency and standardized reporting of filament composition are needed to ensure reproducibility and support informed material selection in FDM applications.

The valorization of waste cooking oils (WCOs) provides a strategy to reduce environmental impact while converting residues from the food industry into valuable products. This study developed and characterized antimicrobial soaps from purified WCOs (sunflower, palm, and pumpkin oils) enriched with natural bioactive ingredients. WCOs were purified by filtration, treatment with 10% NaCl, and bleaching with 3% H₂O₂, followed by cold saponification with NaOH. Twelve soap formulations were prepared, including six enriched with bee products (propolis, poly-floral honey, linden, acacia, honeydew, and sunflower) and six enriched with essential oils (EOs) (clove, rosemary, mace, nutmeg, white pepper, and juniper). The WCOs, natural bioactive ingredients, and soaps were characterized using physico-chemical methods (FTIR, GC-FID, phenols, flavonoids, etc.), while their antibacterial activity was determined against two microbial strains: Staphylococcus aureus and Escherichia coli. The antimicrobial activity of soaps is related to their alkaline pH, while the addition of honey, propolis, or EOs contributes to additional antimicrobial effects. Among honey- and propolis-enriched soaps, those with propolis produced the largest inhibition zones (up to 8.67 mm for S. aureus and 7.0 mm for E. coli). EO-based soaps exhibited higher activity, with rosemary EO-based soap showing the largest zones (up to 9.5 mm for S. aureus and 7.5 mm for E. coli). These data support the potential of enriched soaps containing honey, propolis, and EOs for antimicrobial applications, highlighting their value as a sustainable alternative in the valorization of WCOs.

Puerarin is a naturally occurring isoflavone with reported anticancer activity, yet its topical translation is constrained by limited stability and suboptimal dermal delivery. A Puerarin-loaded proniosomal gel was developed as a potential dermal delivery platform, and we performed an initial assessment of its antimelanoma activity and safety. The gel was produced by coacervation–phase separation using Span 60, Tween 80, phosphatidylcholine, and cholesterol. Physicochemical characterization included pH, entrapment efficiency, rheology, FTIR, DSC, and vesicle properties (DLS, PDI, ζ-potential). In silico geometry optimization and docking were carried out for melanoma-associated targets (MITF and DNMT3B). Biological effects were investigated in vitro on A375 melanoma cells using MTT, morphological analysis, and nuclear/mitochondrial staining, while irritation potential was evaluated in ovo by HET-CAM. The optimized formulation exhibited a skin-compatible pH and an entrapment efficiency of 62 ± 0.26%. DLS indicated a multimodal population, with a major number-weighted vesicle population in the 100–200 nm range, and a ζ-potential of −34.9 ± 0.14 mV. FTIR and DSC supported component incorporation without evidence of chemical incompatibility. The gel showed non-Newtonian, pseudoplastic, thixotropic flow, which is advantageous for topical use. Docking predicted meaningful affinities of Puerarin toward MITF and DNMT3B. The formulation reduced A375 viability in a dose-dependent manner (to 44.66% at 200 µg/mL) and, at higher concentrations, produced nuclear condensation and disruption of the mitochondrial network. HET-CAM classified the gel as non-irritant. The Puerarin-loaded proniosomal gel represents a promising topical platform with preliminary in vitro antimelanoma cytotoxic potential, warranting additional studies to validate skin delivery, efficacy, and safety.

Background/Objectives: In the past two decades, the primary therapeutic use of sildenafil has shifted significantly, from the treatment of angina to managing erectile dysfunction, and since the early 2000s it has been used in the treatment of pulmonary hypertension, particularly pulmonary arterial hypertension. Sildenafil is used as a citrate salt; after oral administration, it presents an absorption of ~90% and an absolute bioavailability of 38%, due to the first-pass effect, such that it belongs to class II of the Biopharmaceutics Classification System. Currently, studies are seeking to obtain new pharmaceutical formulations with an optimized biopharmaceutical profile. In this study, an inclusion complex of sildenafil citrate and 2-hydroxypropyl-beta-cyclodextrin in a molar ratio of 1:1 was obtained and its pharmaceutical compatibility with six pharmaceutical excipients was assessed. For three of these excipients, the presence of chemical interactions with sildenafil citrate has been presented in the literature, and for the other three, compatibility has not been evaluated. Methods: To certify the stoichiometry of the obtained inclusion complex molecular modeling, Job’s method and the Benesi–Hildebrand method were employed. Furthermore, we have described the inclusion complex and the obtained binary mixtures via ATR-FTIR and thermal (TG/DTG and DSC) analysis. Results: The results indicated a lack of chemical interactions between the inclusion complex and the six pharmaceutical excipients at ambient temperature (confirmed by ATR–FTIR investigations) and the presence of chemical interactions between the inclusion complex and three of the excipients when the mixture was heated under non-isothermal conditions (TG/DTG and DSC investigations). Conclusions: This study describes the inclusion complex between sildenafil citrate and 2-hydroxypropyl-beta-cyclodextrin in a molar ratio of 1:1 and its compatibility with several pharmaceutical excipients, results with further applications in the preformulation stage of novel delivery systems.

This paper explores a synthetic pathway for naphtopyrazolotriazines utilizing amines as versatile starting materials. The approach leverages the reactivity of amines to construct the triazine core, fused with naphtho and pyrazolo cycles, through a series of controlled diazo coupling and cyclization reactions. By employing amines, this method allows for the introduction of varied substituents, enabling the tailoring of electronic and steric properties to suit specific potential applications. The significance of this work lies in its efficiency, scalability, and potential to synthesize compounds with tunable functionalities. Naphtopyrazolotriazines are of interest due to the presence of a pyrazolo triazine moiety, which is known for its bioactivity, including anticancer and antimicrobial properties, and their possible utility in optoelectronic materials. All synthesized compounds have been characterized by 1D and 2D NMR, IR, UV-Vis, and mass spectrometry. Additionally, UV-Vis and fluorescence spectra of the synthesized compounds, together with the frontier molecular orbitals energies, were calculated by DFT methods implemented in Gaussian 09W software.

Background/Objectives: In order to enhance the biological activity, novel complexes of N-(2-bromo-phenyl)-2-hydroxy-benzamide derivatives and β-cyclodextrin were obtained. Methods: The inclusion complexes were characterized using spectral and thermal analyses. The antimicrobial activity was determined using the disk diffusion agar method, and completed with the minimum inhibitory concentration (MIC) values obtained by the broth microdilution method. The in vitro anti-inflammatory activity was evaluated using the protease inhibition assay. Results: The computed supramolecular architectures of the inclusion complexes showed that the most stable molecular arrangements correspond to the models in which the N-(2-bromo-phenyl)-2-hydroxy-benzamide derivatives are partially included in the cyclodextrin cavity. The antimicrobial screening showed that the compounds were active against Gram-positive bacteria (MIC = 2.5–5.0 mg/mL). Also, the evaluation of the proteinase inhibitory activity showed that the IC₅₀ values of the title compounds (0.04–0.07 mg/mL) were much lower than that of the acetylsalicylic acid (0.4051 ± 0.0026 mg/mL) used as positive control, proving their superior efficiency in inhibiting trypsin activity. Conclusions: The complexation proved to be beneficial for both antimicrobial and anti-inflammatory effects.

Microplastic pollution has gained attention in recent years due to its adverse impact on the environment. As a major threat to marine ecosystems and biota, the accumulation of microplastics along coastlines has become a growing concern. This study focused on quantifying and characterizing the presence, distribution, and composition of microplastics along the beaches of Romania and Bulgaria. Microplastics were extracted from beach sand samples using a saturated NaCl solution. The particles were then analyzed through FT-IR and DSC spectral analyses to identify their chemical composition. Sampling was conducted across several resorts along the Romanian and Bulgarian coastlines. The findings revealed varying concentrations of microplastics across different beaches, with Romanian beaches showing concentrations of between 40 and 213 particles per sample (470–2500 microplastics/kg), which were notably higher in areas like Mamaia and Costinești. On Bulgarian beaches, the average concentrations reached up to 137 particles per sample (1612 microplastics/kg), particularly in areas like Sunny Beach and Nessebar. Polyethylene (PE) was identified as the most prevalent polymer (55%), followed by polyamide (PA), polypropylene (PP), polyethylene terephthalate (PET), and polyurethane (PU). These polymers were linked to common sources such as packaging, textiles, and industrial products. Microscopic examination, combined with FT-IR and DSC spectral analysis, confirmed the plastic nature of the particles, revealing distinct chemical structures characteristic of each material type. This study underscores the widespread contamination of Romanian and Bulgarian beaches with microplastics, emphasizing the environmental risks to coastal ecosystems. The presence of synthetic polymers highlights the urgent need for policies targeting plastic waste management to mitigate the growing pollution in marine environments.

Carvedilol (CARV) is a nonselective beta and alpha-1 adrenoceptor antagonist commonly indicated for chronic heart failure and hypertension. Its clinical potential is limited by its low aqueous solubility, resulting in poor bioavailability. Encapsulation of CARV by cyclodextrins (CDs) was performed to exceed its solubility-related barriers. This study examines the impact of the CD type and ethanol, as a co-solvent used in the preparation step, on the complexation of CARV with two β-CD derivatives. The inclusion complexes (ICs) were prepared employing the kneading method and investigated using different analytical techniques, including thermoanalytical methods, powder X-ray diffractometry (PXRD), universal attenuated total reflectance Fourier transform infrared (UATR-FTIR) spectroscopy, UV spectroscopy and saturation solubility studies. The binary products of CARV with heptakis(2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD) and randomly methylated β-cyclodextrin (RM-β-CD) exhibit different thermal behavior, different FTIR spectral and diffractometric profiles from those of the parent compounds, emphasizing the interaction between the components and the IC formation. CARV solubility increased 1.78 to 3.32 times as a result of drug complexation with CDs. Analytical data indicate a significant influence of both solvent systems and CD type on the IC solubility, highlighting the CARV/DM-β-CD IC as a promising entity for further research to obtain new formulations containing CARV with improved bioavailability.