Degradation Studies Research Articles

Development and validation of a stability-indicating HPLC method for assay of tonabersat in pharmaceutical formulations

A stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed to assay tonabersat and assess its stability in pharmaceutical formulations. Chromatographic separation was achieved using a Kinetex® C18 column (2.6 µm, 150 x 3 mm, 100 Å) at 50 °C, with a 20 µL injection volume. A linear gradient of acetonitrile in water (5 – 33.5 %) was applied for 1 min, followed by a gradual increase to 100 % over 26 min at a flow rate of 0.5 mL/min. Tonabersat and its degradation products were detected at 275 nm and 210 nm, respectively. The optimized method was used to evaluate the stability of tonabersat in lipid-based pharmaceutical formulations at 5 ± 3 °C, 25 ± 2°C/60 ± 5 % RH, and 40 ± 2 °C/75 ± 5 % RH over 3 months. The method was validated as per ICH guidelines and demonstrated linearity in the range of 5 – 200 µg/mL (R2 = 0.99994) with good accuracy (98.25 – 101.58 % recovery) and precision (% RSD < 2.5 %). The limits of detection and quantitation were 0.8 µg/mL and 5 µg/mL, respectively. Forced degradation studies showed significant degradation on exposure to alkaline (90.33 ± 0.80 %), acidic (70.60 ± 1.57 %), and oxidative stress (33.95 ± 0.69 %) at 70 °C, but no degradation was observed on exposure to thermal or photolytic stress. No chemical degradation was observed in either formulation on storage. Thus, the method was sensitive, specific, and suitable for stability testing of tonabersat in pharmaceutical formulations.

Radiometric characterization of daytime luminescent materials directly under the solar illumination

The materials efficiently emitting photoluminescence (PL) under solar irradiation could find broad applications in passive radiative cooling of buildings, urban heat mitigation, and solar energy harvesting. In this work, we discuss the limitations of common laboratory characterization of such materials (using tunable light sources or solar simulators) and propose a methodology for direct outdoor characterization of PL efficiency under full solar irradiation. A simple, portable radiometry setup with an integrating sphere is described, and its capability of rapid determination of the spectral distribution of the absorbed and emitted power, as well as the overall PL power efficiency and quantum yield, is demonstrated. By characterization of three materials developed for daytime radiative cooling applications, we reveal deviations of obtained parameters caused by the replacement of the real solar irradiation by that of solar simulators. The described method is suitable for studies of long-term stability, photo-induced degradation, or thermal effects.

Mechanism and kinetic study of n-undecane degradation on Co-CeO2: A dual approach combining thermal and plasma catalysis

The catalytic degradation of long-chain alkanes presents a formidable challenge in environmental chemistry. n-Undecane (C11), a quintessential long-chain alkane, predominates as a component of volatile organic compounds (VOCs) emitted from the printing industry and diesel-powered vehicles. The uncontrolled release of these compounds into the atmosphere necessitates stringent measures. This study reports on the plasma-catalytic degradation of n-undecane over the CeO2 based catalysts cooperated with cobalt (Co), manganese (Mn), aluminum (Al), nickel (Ni), iron (Fe), or magnesium (Mg) via aerosol pyrolysis method. Notably, the Co-doped CeO2 catalyst with a Co:Ce atom ratio of 4:1, in conjunction with plasma, achieves an optimal degradation performance. Under the reaction conditions of 90 °C and an energy density of 40 J/L, C11 conversion and COx selectivity reached impressive levels of 100 % and 97 %, respectively. Characterization findings indicate that elevated ratios of Ce3+/(Ce3++Ce4+) and Co3+/(Co2++Co3+) are conducive to the catalytic degradation of C11. Kinetic models have been developed to elucidate the thermal and plasma catalytic degradation mechanisms

Biogenic synthesis of porous CuO nanoparticles: Synergistic effects in photocatalytic dye degradation and electrochemical energy storage applications

This study explores the biogenic synthesis of CuO nanoparticles functionalized with Solanum nigrum, using Acalypha indica leaf extract as a reducing agent. The biogenically synthesized CuO nanoparticles were comprehensively characterized by various analytical techniques, involves X-ray diffraction analysis (XRD), BET surface area analysis (BET), energy-dispersive X-ray spectroscopy (EDAX), X-ray photoelectron spectroscopy (XPS), UV–Visible spectral analysis (UV), Fourier transform infrared spectroscopy (FTIR), fluorescence spectroscopy, photocatalytic degradation, antimicrobial assay, cytotoxicity assay, electrochemical analysis, and linear sweep voltammetry studies. The XRD analysis revealed end centered monoclinic phase with a 10 nm average crystalline size. BET analysis showed a mesoporous structure with a surface area of 11.54 m2/g. XPS and EDAX confirmed the presence of Cu2+ and O2− ions. SEM and TEM images indicated spherical, and porous nanostructures. UV–Visible spectroscopy identified an active optical range of 508–518 nm (2.40–2.45 eV), suggesting potential photocatalytic activity. The photocatalytic degradation efficiencies of Methylene blue (98.8 %) and Rhodamine B (95 %) were achieved after 100 min of irradiation. Antimicrobial tests demonstrated effectiveness against Staph. aureus, E. coli, Shigella flexneri, and Candida tropicalis. The nanoparticles exhibited notable cytotoxicity against colorectal cancer cells with IC50 values of 58.66 μg/ml and 66.78 μg/ml. Additionally, a symmetric supercapacitor electrode using these nanoparticles achieved a specific capacitance of 375 Fg−1 at the current density of 1 Ag−1. This research underscores the versatile applications of biogenic CuO nanoparticles in photocatalysis, antimicrobial treatments, cancer therapy, and energy storage.

Is Degradation in the Eye of the Beholder (or the Researcher)?

When people raise concerns about pornography, they most often are focused on whether pornography increases violence toward women and/or whether it degrades women. While a substantial amount of cross-cultural data suggests that there is no direct link between adult consumption and violence, the question of whether pornography is inherently degrading to women lacks clear answers. As does the question of whether behaviors in pornography that are commonly labeled as degrading are perceived that way when they take place outside pornography. To answer this question about the inherent nature of degradation, we need a better definition and understanding of what particular behaviors people consider to be degrading and whether their perception of what is degrading is influenced by the circumstance or the people involved in a non-pornography setting. To examine this, 496 individuals (247 females, 249 males) were asked to indicate their perceptions of various sexual behaviors when engaged in by males and females toward male and female partners. Results suggest that while some particular sexual behaviors are broadly viewed as degrading (e.g., watersports), perceptions of degradation for other behaviors seem to be influenced by who is doing what to whom. In this sense, the perception of degradation exists in the eye of beholder and is often not defined by the particular sexual act. Future studies of degradation should take into account the context as well as the players involved.

Facile synthesis of Bi2ZnB2O7-MoS2nanocomposite for photodetector and photocatalytic Rhodamine B dye degradation application.

In this research, the visible light active performance of Bi2ZnB2O7(BBZO) was significantly enhanced through the formation of a composite with few layer MoS2. The resultant MoS2@BBZO catalyst was employed in both photocatalysis and photodetector applications. Comprehensive structural and morphological analyses of the MoS2@BBZO catalyst were conducted using x-ray diffraction, Raman spectroscopy, field-emission scanning electron microscopy (FE-SEM), and transmission electron microscopy. The estimated band gaps of BBZO and the composite were found to be 2.8 eV and 1.74 eV, respectively. Rhodamine B degradation studies demonstrated that the catalyst achieved 75% degradation within 30 min. Additionally, the photodetector application was investigated, revealing rapid photo-switching capabilities and an increased photocurrent.

Advanced stability-indicating RP-HPLC method for the quantification of lurasidone hydrochloride in bulk and PLGA-based in situ implant formulation

The aims of the present investigation was to develop and validate stability-indicating RP-HPLC method for the estimation of Lurasidone hydrochloride (LURA-H) followed by its drug product, LURA-H encapsulated poly-D,L lactic-glycolic acid (PLGA) based in-situ depot forming implant (LURA-H-PLGA-ISI). The LURA-H-PLGA-ISI formulation was developed by simple mixing method. According to international conference on harmonization guidelines, RP-HPLC method was developed and validated using Waters 2695 and discovery C18, 5μ, 250×4.6 mm ID column. Force degradation studied were performed by various degradation techniques. The chromatographic separations of LURA-H as well as LURA-H-PLGA-ISI with good resolutions have been achieved using the mobile phase 0.1% orthophosphoric acid and acetonitrile (50:50). The linearity in the range of 25-150 μg/mL of developed method. LOD and LOQ limits for LURA-H were found to be 0.07µg/mL and 0.22 µg/mL, respectively. The % RSD was found to be <2% showing the precision of developed method. The accuracy of developed method was demonstrated which is close to 100±2%. Little modifications in the chromatographic conditions indicated robustness of the developed method. Further, solution stability of LURA-H and LURA-H-PLGA-ISI was stable at room temperature. Furthermore, force degradation studies demonstrated LURA-H was unaffected and stable under thermal, photodegradation and neutral (hydrolytic) stress conditions. AGREE and GAPI assessment demonstrated the developed method is environmentally sustainable. The developed method is simple, robust, precise, accurate and sensitive which can be utilized for the regular analysis of LURA-H in quality control laboratories of bulk drug substance and PLGA containing formulations of LURA-H.

Synthesis, characterization, and biological properties of calcium and zinc based ION incorporated amorphous carbonate nanoparticles

In this study, magnesium (Mg), zinc (Zn), and strontium (Sr) incorporated amorphous calcium carbonate (ACC) nanoparticles were synthesized. Results revealed that at low Zn concentrations, Zn and Sr co-incorporated, Mg-stabilized amorphous calcium carbonate (ACMC) nanoparticles were obtained. However, at high Zn concentrations, instead of ACMC, calcium (Ca) and Sr co-incorporated, magnesium-stabilized amorphous zinc carbonate (AZMC) nanoparticles were obtained. Our results demonstrated that Mg could be used to stabilize the amorphous structure of both nanoparticles. The additive ions could be incorporated into the structure of both ACMC and AZMC without impairing their amorphous nature. The synthesized nanoparticles had an average size of about ∼30 nm. Degradation studies suggested that the degradation rate of AZMC nanoparticles could be slower compared to ACMC nanoparticles. Antibacterial tests showed that the number of colony forming units for the Ca and Sr co-incorporated AZMC nanoparticles was lower for both Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli) strains compared to the control group. Cytotoxicity studies revealed that fibroblasts interacting with the ion-incorporated ACMC and AZMC nanoparticles remained viable and proliferated for up to 5 days in vitro. These results demonstrated for the first time that Zn and Sr co-incorporated ACMC nanoparticles were non-toxic, biodegradable, and possessed antibacterial properties. In addition, Ca and Sr co-incorporated AZMC nanoparticles exhibited a stronger antibacterial effect, which makes them promising candidates for antibacterial applications.

Mucoadhesive poly(ethylene glycol)-based biodegradable polyesters with in-chain model drug

Mucoadhesive polymers have received significant interest in drug delivery due to the prolonged residence time on various mucus gel layers. Not only local effects but also the systemic uptake of active pharmaceutical ingredients can be enhanced by such mucoadhesive excipients. In this study, we design novel poly(ethylene glycol) based mucoadhesive polyesters bearing unsaturated or sulfhydryl functionalities and model drug fluorescein polymerized in the polymeric backbone. The structure of polyesters was confirmed via 1H NMR and FTIR, while their molar masses, determined by gel permeation chromatography, were found to be between 3.6 and 4.0 kDa. Enzymatic degradation studies showed the ability of lipase to degrade the polymeric chains. Because of the mucoadhesive groups, the viscosity of mucus mixtures with these polymers increased 1.8-fold for the double bond, while 4.3-fold for thiol functional polymers, compared to PEG. Prolonged residence time on porcine intestinal mucosa was detected, as 3 h after application, up to 69 % of the polymers were still on the mucosa, whereas PEG was completely removed within 30 mins. Highly pH and enzyme-dependent release of fluorescein was noticed; only pH > 6.8 caused significant drug release. According to the results of this study, PEG-based unsaturated and thiolated polyesters with in-chain model drugs are great mucoadhesive and biodegradable drug carriers with sustained release properties.

Dissociative electrochemical analysis of materials degradation of an anion exchange membrane electrolyser

For anion exchange membrane (AEM) electrolysers, degradation studies provide valuable insights into how individual components degrade. Often, this presents a formidable challenge as each component significantly contributes to overall degradation. Here, we propose a methodology to individually compare the degradation of key components in AEM electrolysers: hydrogen evolution reaction (HER) catalyst, oxygen evolution reaction (OER) catalyst, and the AEM itself. First, to measure the degradation of catalyst-coated substrates (CCS) commonly used in AEM electrolysers, the AEM was replaced with a diaphragm (Zirfon Agfa UTP 500) permeable to OH− ions and stable in alkaline media. Subsequently, a cell with a stable catalytic layer (Nafion-coated Ni-felt substrates) was assembled to focus on membrane degradation with an AEM Sustainion X37-50 Grade 60. Chronopotentiometry and electrochemical impedance spectroscopy (EIS) revealed that the cell with the AEM experienced a threefold increase in ohmic resistance, attributed to the loss of functional groups. Additionally, an ion exchange capacity (IEC) analysis indicated that Sustainion lost approximately 20% of its ion exchange capacity. In contrast, the cell composed of CCS and Zirfon showed lower degradation. EIS data fitting demonstrated increased kinetic-related resistances while the ohmic resistance remained unchanged. This work presents a practical approach for comparing component degradation in AEM electrolysers.

Oxidative stress-induced degradation of Brinzolamide: Isolation and in-depth characterization of unique hydroxylamine and oxime degradation products

Since the safety and efficacy of therapeutic products are strongly related to their stability and purity, impurities including the unavoidable degradation products may affect the pharmacological effect. The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines Q3A requires the identification of process impurities and as well as degradation products in any drug substance to assess the inherent stability of the drug. The present work involves an ICH-guided degradation study for the Brinzolamide (BRZ), a topical ophthalmic drug which is generally used to lower the intraocular pressure (IOP) during glaucoma. Under oxidative stress at room temperature for 20 h, four degradation products (namely BRZ-Pk1, BRZ-PK2, BRZ-Pk3, and BRZ-Pk4) are isolated using advanced chromatographic techniques. Upon confirming the masses of the compounds using High-resolution mass spectrometry (HRMS), functional groups are identified with the help of Fourier-transform infrared spectroscopy (FT-IR). Extensive 1-dimensional (1D) and 2-dimensional (2D) Nuclear Magnetic Resonance spectroscopic (NMR) experiments especially 1D nOe, 1H-13C-HSQC and 1H-13C-HMBC unequivocally confirm the structures. Among the four compounds analyzed, three (BRZ-Pk1, BRZ-Pk2, and BRZ-Pk4) are novel, while BRZ-Pk3 was previously reported solely with mass spectrometric data. Nitrogen-based 2D NMR experiments are crucial for determining the oxidation state of hydroxylamine and oxime products within the molecules, and 1D nOe measurements help confirming E/Z isomerism (geometrical isomerism) for BRZ-Pk2 and BRZ-Pk4. All the proposed structures are justified with appropriate analytical data. The proposed mechanisms are expected to help in identifying the possible degradation pathways for similar pharmaceutical candidates.

Physical characterization of agar-based biodegradable films derived from nonhazardous laboratory waste

Globally, approximately 2.12 billion tons of waste are annually disposed of, with laboratories significantly contributing across diverse waste streams. Effective waste management strategies are crucial to mitigate environmental impact and promote sustainability within scientific communities. This study addresses the challenges by introducing a novel method that transforms laboratory media waste into a valuable biopolymer named “Agastic.” The process involves repurposing agar extracted from bulk laboratory waste, blending it with bio-based plasticizers to produce Agastic sheets exhibiting mechanical properties comparable to traditional bioplastics. Using response surface methodology (RSM) and central composite design (CCD), optimal concentrations of agar (1.5–2.5% w/v), glycerol (0.25–1% v/v), and ethanolamine (0.5–1.5% v/v) were determined. Predictions from Design Expert software indicated impressive tensile strength up to 14.31 MPa for AGA-1 and elongation at break up to 52% for AGA-2. Fourier Transform Infrared Spectroscopy (FTIR) analysis confirmed agarose structural features in AGA-1 and AGA-2. Thermogravimetric analysis (TGA) showed polysaccharide-related breakdown between 38°C and 280°C in AGA-1, peaking at 299.36°C; AGA-2 exhibited diverse thermal decomposition up to 765°C, suggesting their biodegradable potential in packaging applications. Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) analysis confirmed nontoxic nature of Agastic and preserved morphological integrity in both samples. Soil degradation studies revealed AGA-1 and AGA-2 losing 71.31% and 70.88% of weight, respectively, over 15 days. This innovation provides a sustainable pathway to repurpose laboratory waste into eco-friendly bioplastics, particularly suitable for moisture-sensitive packaging such as nursery applications. These findings underscore Agastic films’ promise as environmentally friendly alternatives to traditional plastics, supporting circular bioeconomy principles and significantly reducing ecological impacts associated with plastic waste.

The Study of the Photocatalytic Degradation of Orange II Dye with Wastewater Using New Pyrochlore Solid Solutions Bi1.5Sb1.5Zn1–xCuxO7 as Photocatalysts

The Study of the Photocatalytic Degradation of Orange II Dye with Wastewater Using New Pyrochlore Solid Solutions Bi1.5Sb1.5Zn1–xCuxO7 as Photocatalysts

Quantification of Bictegravir and its impurities: A novel RP-UPLC Approach for Development and Validation.

A new ultra-pressure liquid chromatography (UPLC) method was developed for accurately and reliably quantifying impurities in Bictegravir. The method utilized Waters Acquity HSSC18 column (50mm x 2.1mm, 1.8 µ) at room temperature. The mobile phase consists of Acetonitrile and Buffer (0.1 percent formic acid) in 80:20 and pumped at a flow rate of 0.2 mL/min. This optimized method achieves exceptional separation of Bictegravir and its impurities with excellent resolution at 281 nm. The method’s accuracy is demonstrated by a % recovery range for Bictegravir and its impurities between 99.1% and 100.3%. The correlation coefficient (R²) for BIC and its impurities is consistently above 0.999, indicating high linearity. The method’s robustness was confirmed by its stability against variations in flow rate and mobile phase ratio. Additionally, forced degradation studies confirmed the stability of Bictegravir, highlighting the method’s reliability. Overall, developed UPLC method is precise, accurate, robust, and linear, making it suitable for routine analysis of BIC-related substances in quality control laboratories at manufacturing sites during commercial production.

Synergistic enhancement of the photocatalytic activity of g-C3N4 via in-situ surface alkalization and CQDs loading strategies

The CQDs/alkaline carbon nitride heterojunction photocatalysts were synthesized employing dicyandiamide as the nitrogen material, Citric acid was used as the carbon source, while KCl and NH4Cl were as alkaline reagents. The study investigated the influence of CQDs on the adsorption performance, photocatalytic activity, and band structure of alkalized carbon nitride. The dark adsorption results revealed that CNK/CQDs1: 12 exhibited outstanding adsorption performance, capable of degrading adsorbed pollutants in a relatively short period. The photocatalytic degradation study demonstrates that CNK/CQDs1:12 exhibits significantly higher degradation efficiencies compared to the pristine CN and alkalinized CNK samples, with degradation efficiencies of 94.4 % for Methylene Blue (MB) and 71.68 % for tetracycline hydrochloride (TC-HCl) within 60 min. This is due to the synergistic effects of alkalization of the g-C3N4 surface and CQDs loading, which modified the heterojunction interfacial charge transfer efficiency, suppressing the recombination of photoelectron-hole pair, extending the life span of transient photogenerated carriers, thereby improving photocatalytic activity. Free radical trapping experiment indicated that h+ and ·O2− are the primary active species during the photocatalytic degradation process of CNK/CQDs1:12.

UPLC Estimation of an Antidiabetic Drug by Method Development and Validation Followed by Stability Indicating Studies.

The analytical method development and validation of a common antidiabetic drug, Canaglifozin, by taking the aid of ‘Ultra High-Performance Liquid Chromatography’, along with stability indicating method. The canaglifozin drug was eluted from the optimized mobile phase in 70:30 ratio of water and methanol, at 1 ml/ min flow rate, under separation with C18 column of 100 x 2mm size with 1.8 diameters at isocratic mode. The detection was carried at 286 nm wavelength, resulting in 3.80 retention time, as run time being 10 min. The detection limit and quantification limit, was noticed at ‘0.0039 and 0.0119 µg/ ml’ correspondingly. The percentage RSD and recovery percentage was under ICH guidelines only. The stress degradation studies under acid, basic, neutral, and thermal conditions were carried on.

QbD-Driven Approach to Cleaning Method Development and Validation for Darunavir Analysis in Oral Films.

The current investigations involve developing a high-performance liquid chromatographic method that’s simple to operate, fast to establish, accurate, precise, and economical through design-enabled methods. A positive experimental design is offered to utilize the central composite design of pH and the mobile phase, two crucial components of the RP-HPLC technology. The chromatographic conditions were optimized with the release of Design Expert software version 13.0. Symmetry C18 column (4.6×150mm, 5µm) was used in the procedure, along with acetonitrile (20:80 v/v) and potassium dihydrogen orthophosphate buffer pH 4.0 as the mobile phase. There was a 0.70 ml/min flow rate. 263 nm is the wavelength of detection. Darunavir’s sharp, resolved peak was seen 2.3 minutes after swabbed samples from the 10*10 cm SS plate were injected. A linear calibration curve with an R2 of 0.9991 was observed in the concentration range of 0.25 to 25µg/ml. For precision %RSD is 1.03,1.48. Accuracy % concentration 50%,100%,150% mean recovery 99.43-100.53.LOD &amp; LOQ 1.12µg/ml, 3.39µg/ml. Robustness was tested with modest modifications to the wavelength and flow rate. Forced degradation studies were carried out and found to be within the limits. the degradation parameters such as Acid, Base, Oxidative, Photolytic, and thermal degradation parameters are according to the ICH guidelines. % Assay was done for oral films and it was found to be within the limits. Thus, the outcomes unequivocally demonstrated that the QbD technique could be effectively used to enhance the HPLC method for the measurement of darunavir in production settings.

Gabapentin: An impurity profiling approach with hydrogen peroxide induced thermal oxidation in autoclave

Predicting unconventional pathways in long term stability studies can be very challenging, especially in solid state degradation. This is of vital importance for enhancement in the level of degradation and to further enable the isolation of unknown degradation products. Predicting the mechanism or pathway also help in designing control strategies to minimise the potential chances of impurity formation. In this context, the lagtime of most oxidative degradation mechanisms is extremely important, which allows enough requisite of free radicals etc., one of the unconventional pathways. This is difficult to replicate in degradation studies involving usual solution form. In this investigation, we demonstrate that employing autoclave degradation with hydrogen peroxide conditions provide an enhanced level of an unknown degradation product, which was found to be futile in traditional forced degradation studies. The conditions used probably bypass the lag time. This impurity has been isolated using preparative liquid chromatography (Prep-HPLC) method and spectroscopic techniques like high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance NMR (1H, 13C, DEPT-135, NOESY, APT) for elucidation of the molecular structure. The impurity was identified as a dimer of gabapentin impurity-A (impurity (2,2′-diaza[l,2′-bispiro[4.5]decane]-3,3′-dione) and named it as impurity-U. A plausible mechanism for the formation of isolated impurity is proposed. HPLC methods have been developed and reported for the determination of gabapentin and its related substances using UV detection.

Comprehensive Analysis of Cetuximab Critical Quality Attributes: Impact of Handling on Antigen-Antibody Binding.

Cetuximab, formulated in Erbitux® (5 mg/mL), is a therapeutic monoclonal antibody (mAb) widely used in several cancer treatments. Currently, there is insufficient knowledge about the behavior of cetuximab with regard to the risk associated with its routine handling or unintentional mishandling in hospitals. Forced degradation studies can simulate these conditions and provide insights into the biophysical and biochemical properties of mAbs. In this study, we conducted a deep physicochemical and functional characterization of the critical quality attributes of cetuximab in control samples and under controlled degraded conditions, including freeze-thaw cycles, heat, agitation, and light exposure. To achieve this purpose, we used a set of proper analytical techniques, including CD, IT-FS, DLS, SE/UHPLC-UV, UHPLC-MS/MS, and ELISA, to check functionality based on antigen-antibody binding. The results revealed that light exposure was the stress stimuli with the greatest impact on the drug product, leading to the formation of non-natural oligomers, fragmentation, and oxidation of methionine residues. Additionally, cetuximab (Erbitux®, 5 mg/mL) showed a tendency to aggregate when submitted to 60 °C for 1 h. In terms of functionality, cetuximab (Erbitux®, 5 mg/mL) samples were found to be affected when subjected to freeze-thaw cycles, 60 °C (1 h), and when exposed to light (daylight with room temperature excursion and accelerated light exposure). Thus, we suggest that Erbitux® (5 mg/mL) should be shielded from these environmental conditions, as they compromise both the safety and efficacy of the drug product.

Au/ZnO nanocomposites based on simple laser ablation method for water treatment

A binary heterostructure of Au/ZnO nanocomposite is prepared in a novel way based on successive pulsed laser ablation of the two targets in an aqueous solution with varied pulse time. The development of the method allows generating a noble metal (Au) and metal oxide (ZnO) one after one to produce a novel heterostructure with a tunable shell applicable as a catalytic degradable material. The nanocomposite samples are tested to study their optical, morphological, and structural properties. The photocatalytic degradation study demonstrates a significant decrease in the absorbance intensity of Rohdamin B (RhB) dye as the irradiation time increases. It indicates a reduction in dye concentration with a remarkable improvement in contact time. Besides, the degradation percentage against pH value is investigated. It reveals an increasing trend as the pH value rises with a maximum percentage at pH 10. The study is also concerned with the influence of the initial concentration of RhB dye on the degradation efficiency of the nanocomposite. Higher initial concentrations of the dye lead to a decrease in the degradation efficiency of the catalysts. Finally, the kinetic analysis of RhB photodegradation reveals that the Langmuir-Hinshelwood first-order kinetic model accurately describes RhB's adsorption onto the nanocomposites.