Phosphate Buffer pH Research Articles

Rapid Detection of the Anti-Tumor Drug Etoposide in Biological Samples by Using a Nanoporous-Gold-Based Electrochemical Sensor.

Monitoring etoposide is important due to its wide usage in anti-tumor therapy; however, the commonly used HPLC method is expensive and often requires complicated extraction and detection procedures. Electrochemical analysis has great application prospects because of its rapid response and high specificity, sensitivity, and efficiency with low cost and high convenience. In this study, we constructed a nanoporous gold (NPG)-modified GCE for the detection of etoposide. The electrochemical oxidation of etoposide by NPG caused a sensitive current peak at +0.27 V with good reproductivity in 50 mM of phosphate buffer (pH 7.4). The relationship between etoposide concentration and peak current was linear in the range between 0.1 and 20 μM and between 20 and 150 μM, with a detection sensitivity of 681.8 μA mM-1 cm-2 and 197.2 μA mM-1 cm-2, respectively, and a limit of detection (LOD) reaching 20 nM. The electrode had a good anti-interference ability to several common anions and cations. Spiked recovery tests in serum, urine, and fermentation broth verified the excellent performance of the sensor in terms of sensitivity, reproducibility, and specificity. This may provide a promising tool for the detection of etoposide in biological samples.

Cadmium Toxicity-Induced Changes in Antioxidative Enzyme Levels in Freshwater Catfish Channa Punctatus (Bloch)

Present study has been planned to observe the effect of Cadmium chloride on the locally available economically important edible fish _Channa punctatus _(body weight 27.04±0.19 g and length 16.7±0.20 cm). To assess the effect of cadmium in terms of enzymatic and non-enzymatic assays, laboratory studies have been done. Fish were acclimatized and treated separately with concentrations of 35 mg/L and 70 mg/L of CdCl2. The livers were dissected out and homogenized in 0.1 M sodium phosphate buffer (pH 7.4). Biochemical analyses were done for lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), and protein estimations. The results were shown as mean and standard error (Mean ± SEM). The analyses of variance (ANOVAs) were analysed and significantly applied for the Dunnett test for multiple comparisons of groups against the control, which determined the significant differences among the groups. This study is of academic importance and will provide valuable information regarding cadmium toxicity. At the same time, it will address the public health issue as far as consumption of fishes from contaminated water is concerned.

Development and validation of a stability-indicating analytical method for simultaneous determination of sodium phenylbutyrate and taurursodiol in bulk and formulation using reverse phase ultra-performance liquid chromatography

Background Amyotrophic Lateral Sclerosis, often known as Lou Gehrig’s disease, is typically treated with a combination therapy that includes both sodium phenylbutyrate (SPB) and taurursodiol (TRS). Objectives To assess both SPB and TRS in bulk and their dosage form concurrently, a stability-indicating analytical method was developed and validated using Ultra-Performance Liquid Chromatography. Patients and methods The chromatographic separation was carried out on a Waters C18 Column, with dimensions of 150×4.6 mm i.d. and a particle size of 2 μm. A mobile phase consisting of a phosphate buffer pH 2.5 with methanol in the ratio of 45 : 65 v/v was, then delivered at a flow rate of 1 ml/min. Detection of the analytes occurred at 285 nm using a photo diode array detector. An auto sampler injected a 10 μl sample into the column, and the column was maintained at a temperature of 30°C. Results and conclusion SPB and TRS were eluted at 1.483 and 2.492 nm, respectively. Linearity was established in the range of 567–1701 μg/ml for SPB and 189–567 μg/ml for TRS. The robustness of the method was assessed by intentionally modifying parameters such as flow rate, detection wavelength, and column temperature. Furthermore, studies on forced degradation under various stress conditions, including acid, base, peroxide, heat, and ultra violet exposure, indicated the method’s capability to identify stable materials. In summary, the developed analytical approach for simultaneously determining SPB and TRS in bulk and their formulation was found to be specific, accurate, precise, and reliable.

Analysis of atorvastatin in environmental waters: Validation of an electrochemical molecularly imprinted polymer sensor with application of life cycle assessment

The widespread presence of pharmaceuticals in wastewater effluents after treatment stands as a significant challenge faced in the field of wastewater management and public health. Governments and the scientific community have worked to meet this urgent need for effective solutions. Nevertheless, the development of detection strategies for pharmaceutical monitorization capable of delivering rapid, on-site, and sensitive responses remains an ongoing necessity. In this work, the performance of a previously developed molecularly imprinted polymer (MIP) based electrochemical sensor for detecting atorvastatin (ATV) in wastewater effluents and surface waters is presented. A simple preconcentration method followed by electrochemical measurements by differential pulse voltammetry (DPV) in 0.1 M phosphate buffer (pH = 7), was implemented. The analytical results were validated with those obtained on a set of 16 water samples by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Additionally, a life cycle assessment (LCA) was conducted to compare the environmental impact of both methodologies. The results obtained demonstrated that ATV detection using MIP-sensor was reliable when compared to the results found by UHPLC-MS/MS presenting a robust linear correlation coefficient of 0.843. The LCA results show that the novel MIP-sensor technique has lower associated environmental impacts than UHPLC-MS/MS, when the current analytical protocol for pharmaceuticals detection is applied. These findings highlight the potential of the developed MIP-sensor as an eco-friendly analytical tool for routine analysis and point-of-care monitoring of ATV in WWTP wastewater and surface water samples.

First Report of rattail cactus necrosis-associated virus Infecting Prickly pear (Opuntia macrocentra) in the United States.

Black-spined prickly pear (Opuntia macrocentra Engelmann; Cactaceae) is a cactus native to Arizona, New Mexico, Texas, and northwest Mexico. The plant is often grown for ornamental purposes in the United States. In February 2023, virus-like symptoms such as concentric ringspots and chlorotic spots were observed on O. macrocentra plants grown at the vicinity of Maricopa County Cooperative extension, University of Arizona, Phoenix, AZ (33°24'24.6"N, 111°59'15.3"W). Total RNA was extracted from two samples (YPHC-60-A and YPHC-60-B), following the protocol by Tzanetakis et al. (2007). Reverse transcription polymerase chain reaction (RT-PCR) was performed with degenerate tobamovirus, TobamodF/TobamodR (Li et al. 2018) and potexvirus, 1RC, Potex 2RC, and Potex 5 (van der Vlugt and Berendsen 2002) primers. An expected amplicon of ~880 bp was obtained from both samples using TobamodF/TobamodR primers, while no amplification was observed with potexvirus primers. Further, RT-PCR was carried out using species-specific primers to detect cacti related tobamoviruses: cactus mild mottle virus (CMMoV), rattail cactus necrosis-associated virus (RCNaV) (Park et al. 2018) and Opuntia virus 2 (Salgado-Ortiz et al. 2020). Amplicons of ~540 bp were amplified from both samples using RCNaV specific primers, whereas no amplification was obtained using CMMoV and Opuntia virus 2 specific primers. Then, the amplicons from both YPHC-60 (A-B) isolates (~540 bp) were Sanger sequenced and shared 99.22% nucleotide identity to each other. A BLAST search revealed 93% nucleotide identity with RCNaV CP sequences (KY581586.1, JF729471, and MT130378.1). The sequences were submitted in the GenBank (accessions no. OQ914798 and OR828526). Furthermore, complete RCNaV- RNA dependent RNA polymerase (RdRP) gene was amplified using primers 3490-s-5'GTAGGTGGTACCGCATAGCA-3'; 3490as 5'AAACGCAAGTCMRYGACYGA-3' (designed in this study from accession no. JF729471.1, position 3490-3509 and 4905-4925). The expected amplicons of ~1,500 bp were obtained from both YPHC-60 (A-B) samples and sequenced (GenBank: OQ914799 and OR823954) showing 87.5 % identity with RCNaV sequences (JF729471.1 and NC_016442.1). The maximum-likelihood phylogenetic tree clustered YPHC-60 (A-B) isolates in a single clade with other RCNaV isolates. RCNaV virus particles were isolated from YPHC-60 (A-B) and submitted for RNA extraction, testing positive for RCNaV by RT-PCR. Sap extract of YPHC-60 (A-B) prepared in 0.01 M phosphate buffer (pH =7.0) was used to mechanically inoculate 3 indicator plant species (n=10): Phaseolus vulgaris, Medicago sativa, and Cucumis melo. Also, infected tissue was used to graft Opuntia sp. plants. Symptoms such as local lesions were observed on M. sativa and vein thickening on P. vulgaris 14 days post-inoculation, while Opuntia sp. showed chlorosis 30 days after grafting. RCNaV infection in mechanically inoculated P. vulgaris, M. sativa, and Opuntia sp. was also confirmed through RT-PCR. C. melo and non-inoculated control plants did not show any symptoms, nor tested positive through RT-PCR. RCNaV has been reported earlier to infect cactus species in South Korea (Park et al. 2018) and O. albicarpa in Mexico (De La Torre-Almaráz et al. 2016), where it was found in several orchards. To the best of our knowledge, this is the first report of RCNaV infecting O. macrocentra in the United States. This study highlights that RCNaV is easily transmitted mechanically or by grafting, which could impact the nursery industry as most cacti are clonally propagated.

Formulation and Evaluation of Indomethacin Sustained Release Tablet by using Natural Polymers

Arthritis is most prevalent disorder and Indomethacin is choice of drug for arthritis. Oral route is most preferred route of drug administration and tablets are the more convenient dosage form. In present research natural polymers guar gum and xanthan gum were used to make sustained release tablet of Indomethacin. Indomethacin release from the tablets was studied in phosphate buffer pH 7.2. The drug release pattern of six different formulations in which xanthan gum and guar gum were used as a retarding material in different proportions was shown in table no. 6. The formulation F1 releases (75.20%) upto 12 hrs whereas the formulation F2 releases the drug (98.81%) in same time. The formulations F3, F4, F5 and F6 release 98.32%, 99.29%, 98.79% and 82.40% respectively. The dissolution pattern of both gums was similar i.e. with drug to polymer ratio (1:1). In present work F1 shows best sustained release upto 12 hrs in which Drug to Polymer ratio was 1:1:0 (Drug : Xanthan gum : Guar gum). In formulation F2 drug release was not sustained and complete release occurs in 12 hrs where the Drug to Polymer ratio was 1:1.67:0 (Drug: Xanthan gum : Guar gum). It was found that on the concentration of xanthan gum decreases the release rate of the drug also decreases. For sustain release there is not much role of Guar Gum reported. Indomethacin drug has been selected which has half-life 4.5 hrs. Hence the present work, an attempt has been made to provide sustained release drug delivery using polymers with Indomethacin as the model drug. Xanthan gum was best able to retard Indomethacin release mechanism even in the presence of a polymer. Polymer can be used to formulate successful sustained release Indomethacin matrix tablets that have desirable characteristics.

Heterologous Expression and Characterization of a Novel Mesophilic Maltogenic α-Amylase AmyFlA from Flavobacterium sp. NAU1659.

A novel amylase AmyFlA from Flavobacterium sp. NAU1659, AmyFlA, was cloned and expressed in Esherichia coli. Based on phylogenetic and functional analysis, it was identified as a novel member of the subfamily GH13_46, sharing high sequence identity. The protein was predicted to consist of 620 amino acids, with a putative signal peptide of 25 amino acids. The enzyme was able to hydrolyze soluble starch with a specific activity of 352.97 U/mg at 50°C in 50 mM phosphate buffer (pH 6.0). The Km and Vmax values of AmyFlA were respectively 3.15mg/ml and 566.36 µmol·ml-1·min-1 under optimal conditions. Its activity towards starch was enhanced by 63% in the presence of 1 mM Ca2+, indicating that AmyFlA was a Ca2+-dependent amylase. Compared to the reported maltogenic amylases, AmyFlA produced a lower variety of intermediate oligosaccharides at the start of the reaction so that the product mixture contained a higher proportion of maltose. These results indicate that AmyFlA may be potential application value in the production of high-maltose syrup.

Preparation and Evaluation of a Self-Emulsifying Drug Delivery System for Improving the Solubility and Permeability of Ticagrelor.

Ticagrelor (TCG) is a BCS class IV antiplatelet drug used to prevent platelet aggregation in patients with acute coronary syndrome, having poor solubility and permeability. The goal of this study was to develop a self-nanoemulsifying drug delivery system (SNEDDS) of TCG to improve its solubility and permeability. The excipients were selected based on the maximum solubility of TCG and observed by UV spectrophotometer. Different combinations of oil, surfactant, and co-surfactant (1:1, 2:1, and 3:1) were used to prepare TCG-SNEDDS formulations, and pseudo-ternary phase diagrams were plotted. The nanoemulsion region was observed. Clove oil (10-20%), Tween-80 (45-70%), and PEG-400 (20-45%) were used as an oil, surfactant, and co-surfactant, respectively. The selected formulations (F1, F2, F3, F4, F5, and F6) were analyzed for ζ potential, polydispersity index (PDI), ζ size, self-emulsification test, cloud point determination, thermodynamic studies, entrapment efficiency, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), in vitro dissolution, ex vivo permeation, and pharmacodynamic study. The TCG-SNEDDS formulations exhibited ζ potential from -9.92 to -6.23 mV, a ζ average of 11.85-260.4 nm, and good PDI. The in vitro drug release in phosphate buffer pH 6.8 from selected TCG-SNEDDS F4 was about 98.45%, and F6 was about 97.86%, displaying improved dissolution of TCG in 0.1 N HCl and phosphate buffer pH 6.8, in comparison to 28.05% of pure TCG suspension after 12 h. While the in vitro drug release in 0.1 N HCl from F4 was about 62.03%, F6 was about 73.57%, which is higher than 10.35% of the pure TCG suspension. In ex vivo permeability studies, F4 also exhibited an improved apparent permeability of 2.7 × 10-6versus 0.6708 × 10-6 cm2/s of pure drug suspension. The pharmacodynamic study in rabbits demonstrated enhanced antiplatelet activity from TCG-SNEDDS F4 compared to that from pure TCG suspension. These outcomes imply that the TCG-SNEDDS may serve as an effective means of enhancing TCG's antiplatelet activity by improving the solubility and permeability of TCG.

Reliable quality of R-phycoerythrin derived from Portieria hornemannii for effective antioxidant, antibacterial, and anticancer activity

The phycobiliprotein is a light-harvesting fluorescent probe; Phycoerythrin is a pigment used in many industrial, and pharmaceutical applications; including fluorescence resonance energy transfer and flow cytometry. The main objective of the current study was purifying the phycoerythrin in Portieria hornemannii. The phycoerythrin pigment was dialyzed commonly using Q sepharose, but it is high cost. However, the alternative method is DEAE-Sephadex is cost-effective, high- yield, pure compound, and has high activity performance. Then the R-Phycoerythrin (R-PE) compound was extracted in 0.02 M of phosphate buffer (pH–7.2). R-PE investigated the FT-IR, HPLC, SDS-PAGE and including physico-chemical properties. Then the purified R-PE compound was evaluated by an antibacterial, antioxidant, and anticancer activity. The R-Phycoerythrin was showing a maximum inhibition effect of high concentration (IC50value 77.98 µg/ml) against the colon cancer HT-29 cell line.

Preparation, In Vitro Characterization, and Evaluation of Polymeric pH-Responsive Hydrogels for Controlled Drug Release.

The purpose of the current research is to formulate a smart drug delivery system for solubility enhancement and sustained release of hydrophobic drugs. Drug solubility-related challenges constitute a significant concern for formulation scientists. To address this issue, a recent study focused on developing PEG-g-poly(MAA) copolymeric nanogels to enhance the solubility of olmesartan, a poorly soluble drug. The researchers employed a free radical polymerization technique to formulate these nanogels. Nine formulations were formulated. The newly formulated nanogels underwent comprehensive tests, including physicochemical assessments, dissolution studies, solubility evaluations, toxicity investigations, and stability examinations. Fourier transform infrared (FTIR) investigations confirmed the successful encapsulation of olmesartan within the nanogels, while thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) studies verified their thermal stability. Scanning electron microscopy (SEM) images revealed the presence of pores on the surface of the nanogels, facilitating water penetration and promoting rapid drug release. Moreover, powder X-ray diffraction (PXRD) studies indicated that the prepared nanogels exhibited an amorphous structure. The nanogel carrier system led to a significant enhancement in olmesartan's solubility, achieving a remarkable 12.3-fold increase at pH 1.2 and 13.29-fold rise in phosphate buffer of pH 6.8 (NGP3). Significant swelling was observed at pH 6.8 compared to pH 1.2. Moreover, the formulated nexus is nontoxic and biocompatible and depicts considerable potential for delivery of drugs and protein as well as heat-sensitive active moieties.

Comparative Evaluation of Cefixime Microspheres Utilizing a Natural Polymer and a Synthetic Polymer

Background:: Microspheres are naturally biodegradable, free-flowing powders with a particle size of less than 200 micrometres that are comprised of proteins or synthetic polymers. Using microspheres is a reliable strategy to ensure that the drug is accurately delivered to the target area and that the right concentration is kept there without having any unfavourable side effects. Objective:: The objective of the present study was to create a sustained-release cefixime trihydrate microsphere delivery system employing natural and synthetic polymers as a carrier and increase therapeutic effectiveness. Methods:: Due to the simplicity of processing, the solvent injection method was used to create microspheres. Microspheres were created with this technology using the sustained-release polymer, sodium alginate, and active material (drug). The compatibility of components with the drug was evaluated using XRD and FT-IR. In an in-vitro release research, the dissolving medium was phosphate buffer at pH 6.8. For the kinetic analysis of the drug release mechanism, graphs for zero-order, first-order, Higuchi's, Korsmeyer-Peppas, and Hixson-Crowell models were also created. Results:: The best formulation was chosen from the batches, and in-vitro cefixime trihydrate release studies for various microspheres containing cefixime trihydrate in phosphate buffer (pH 7.4) for 8 hours were performed. The dissolution profiles of formulations F4 and F8 showed that the formulation, including xanthan gum, F8, released 55.01% more medication in 8 hours than the formulation using HPMC, F4. X-ray diffraction, swelling index of drug-laden microspheres, and Scanning Electron Microscopy were used to evaluate formulation F8. The graphs for zero-order, first-order, Higuchi's, Korsmeyer-Peppas, and Hixson- Crowell models were plotted, and the optimised batch was discovered to match Higuchi's drug release kinetics with an R2 value of 0.990. Conclusion:: Cefixime trihydrate microspheres can be utilized as a new drug delivery technology to minimize dose frequency and, as a result, to promote patient compliance.

Core-Shell Nanocables Decorated with Carbon Spherical Shells and Silver Nanoparticles for Sensing Ethinylestradiol Hormone in Water Sources and Pills.

The selective, rapid detection of low levels of hormones in drinking water and foodstuffs requires materials suitable for inexpensive sensing platforms. We report on core-shell Ag@C nanocables (NCs) decorated with carbon spherical shells (CSSs) and silver nanoparticles (AgNPs) by using a hydrothermal green approach. Sensors were fabricated with homogeneous, porous films on screen-printed electrodes, which comprised a 115 nm silver core covered by a 122 nm thick carbon layer and CSSs with 168 nm in diameter. NCs and CSSs were also decorated with 10-25 nm AgNPs. The NC/CSS/AgNP sensor was used to detect ethinylestradiol using square wave voltammetry in 0.1 M phosphate buffer (pH 7.0) over the 1.0-10.0 μM linear range with a detection limit of 0.76 μM. The sensor was then applied to detect ethinylestradiol in tap water samples and a contraceptive pill with recovery percentages between 93 and 101%. The high performance in terms of sensitivity and selectivity for hormones is attributed to the synergy between the carbon nanomaterials and AgNPs, which not only increased the sensor surface area and provided sites for electron exchange but also imparted an increased surface area.

INCREASED DISSOLUTION RATE OF ACECLOFENAC BY FORMATION OF MULTICOMPONENT CRYSTALS WITH L-GLUTAMINE

Objective: The objectives of this research were to improve the solubility as well as the rate of dissolution of aceclofenac (ACF) through the formation of multicomponent crystals (MCC) with L-glutamine (LGLN) as a coformer and following the liquid-assisted grinding (LAG) technique.
 Methods: MCC of ACF and LGLN was formed by Liquid Assisted Grinding (LAG) technique. Powder X-ray Diffractometer (PXRD), Differential Scanning Calorimeter (DSC), Fourier Transform Infrared (FT-IR) spectrometer, Particle Size Analyzer (PSA), and Scanning Electron Microscope (SEM) were used for MCC characterization. Solubility and dissolution test were determined using ultraviolet-visible (Uv-Vis( spectrophotometer.
 Results: The results showed a decrease in the diffraction peak intensity, melting point, and enthalpy of fusion. FT-IR analysis showed a non-significant wavenumber shift compared to intact components. These characterizations showed that MCC formed a eutectic mixture. SEM and particle size analysis showed a homogeneous particle rod shape and decreased particle size. ACF's solubility in MCC increased 2.21 times more than intact form. MCC's dissolution rate increased by 5.34 times and 5.56 times, respectively, after 60 min in phosphate buffer pH 6.8 and CO2-free distilled water.
 Conclusion: The formation of MCC of ACF and LGLN considerably enhances ACF's solubility and dissolution rate.

Nanoparticles of Thiolated Xanthan Gum for the Oral Delivery of Miconazole Nitrate: In Vitro and In Vivo Evaluation.

The objective of this research was to develop a mucoadhesive delivery system that improves permeation for the administration of poorly absorbed oral medications. Thiolation of xanthan gum (XGM) was carried out by esterification with mercaptobutyric acid. Fourier-transformed infrared spectroscopy was used to confirm thiol-derivatization. Using Ellman's technique, it was revealed that the xanthan-mercaptobutyric acid conjugate had 4.7 mM of thiol groups in 2 mg/mL of polymeric solution. Using mucosa of sheep intestine, the mucoadhesive properties of XGM and thiolated xanthan gum (TXGM) nanoparticles were investigated and we found that TXGM had a longer bioadhesion time than XGM. The disulfide link that forms between mucus and thiolated XGM explains why it has better mucoadhesive properties than XGM. A study on in vitro miconazole (MCZ) release using phosphate buffer (pH 6.8) found that TXGM nanoparticles released MCZ more steadily than MCZ dispersion did. A 1-fold increase in the permeation of MCZ was observed from nanoparticles using albino rat intestine compared to MCZ. Albino rats were used to test the pharmacokinetics of MCZ, and the results showed a 4.5-fold increase in bioavailability. In conclusion, the thiolation of XGM enhances its bioavailability, controlled release of MCZ for a long period of time, and mucoadhesive activity.

Comparative Analysis of PEG-Free and PEG-Based Self-Emulsifying Drug Delivery Systems for Enhanced Oral Bioavailability of Therapeutic (Poly) Peptides.

This study aims to compare the potential of Polyethylene glycol (PEG-free and PEG-based self-emulsifying drug delivery systems (SEDDS) for the oral administration of insulin glargine (IG). Hydrophobic ion pairs (HIPs) of IG are formed using various counterions. HIPs are assessed for log P octanol/water and dissociation behavior. They are incorporated into SEDDS based on polyglycerol (PG) and zwitterionic surfactant (ZW) using response surface methodology and compared to conventional PEG-SEDDS in size, stability, and log D SEDDS/release medium. Oral IG bioavailability in PG/ZW-SEDDS and PEG-SEDDS is evaluated in rats. Among the various counterions studied, IG-BIS (bis(isotridecyl)sulfosuccinate) HIPs demonstrated the highest log P and an improved dissociation profile. PG/ZW-SEDDS and PEG-SEDDS have similar ≈40nm sizes and are stable over 24 h. Both formulations have log D > 4 in water and >2 in 50mM phosphate buffer pH 6.8. PG/ZW-SEDDS yielded an oral bioavailability of 2.13 ± 0.66% for IG, while the employment of PEG-SEDDS resulted in an oral bioavailability of 1.15 ± 0.35%. This study highlights the prospective utilization of PEG-free SEDDS involving the concurrent application of PG and ZW surfactants, an alternative to conventional PEG surfactants, for improved oral therapeutic (poly) peptide delivery.

Abstract B043: Radiolabelled Trastuzumab Fab as a theranostic agent for HER2 expressing breast cancer

Abstract Breast cancer is the most common cause of mortality among women worldwide. Among all subtypes, HER2-positive breast cancers are highly aggressive and have poor prognosis. Surgical resection is choice of treatment. However, surgery may not be possible if disease is widespread. Trastuzumab, a monoclonal antibody, is globally used for immunotherapy. It is a large sized molecule (141kDa) and show slow pharmacokinetics and high liver uptake. We have explored trastuzumab fragment as a radio-theranostic agent. Trastuzumab Fab was generated using Papain enzyme tagged beads, incubation time 18 to 20 h at 850 rpm in phosphate buffer. Fab were collected with ultrafiltration device, cut off 30 kDa, in phosphate buffer pH 8. Quantification of Fab was done at 280 nm. Fab characterization was done using MALDI-TOF and SDS-PAGE. To enable radiolabelling of Fab with Ga-68 and Lu-177, Fab was conjugated with bifunctional chelator, DTPA. Fab-DTPA was separated by micro bio-spin P-6 chromatography columns and the average number of DTPA/Fab were calculated. Affinity of Fab conjugated Fab-DTPA for HER2 receptors was studied using the biolayer interferometry technique (BLI). Radiolabelling of Fab with Ga-68 for PET imaging and Lu-177 for therapy was optimized. Quality control included radiochemical purity using TLC in sodium citrate (pH 5) mobile phase, pyrogenicity using PTS, and sterility by tryptic soy broth culture media. Receptor affinity and apoptosis were studied with HER2 positive SKBR-3 cells using flow cytometry assay. The SKBR-3 cell (106) were cultured in 96 well plates and incubated with a known amount of Lu-177-DTPA-Fab (0- 18.5 MBq). First in human Ga-68 Fab PET/CT and Lu-177-Fab gamma camera images were acquired after obtaining clearance from Institutional Ethics Committee and inform signed consent. Patients were recruited with histopathological proven HER2 positive breast cancer and uptake on F-18 FDG PET/CT. Ga-68-DTPA-Fab (3.5-5 mCi) and 10-15 mCi Lu-177 DTPA-Fab was injected and images were acquired at 2/3 h and up to 7 days respectively. Dominant Fab peak at 45kDa on MALD-TOF, single band on SDS-PAGE (Non-reduced or reduced) have been obtained. Two DTPA/Fab were conjugated and confirmed by MALDI-TOF. BLI data showed Kd value of trastuzumab, Fab, and conjugated DTPA-Fab as 0.2 nM, 0.57 nM, and 20 nM for HER2. High labelling efficiency (≥98%) of Lu-177-DTPA-Fab and Ga-68-DTPA-Fab was achieved. Apoptosis (%) was 1.5%- 42.5% in SKBR-3 cells treated with Lu-177-DTPA-Fab. Both formulations were found sterile and pyrogen-free. Kidney and bladder activity of Ga-68/Lu-177-DTPA-Fab demonstrate renal clearance. Blood pool activity of both tracers were high. However, it was decreased, and lesion uptake was increased with time. All the lesions on Ga-68-DTPA-Fab, same as in F-18 FDG PET/CT, were picked up accept those near heart. Good lesion retention of Lu-177-DTPA-Fab was observed showing suitability for therapy. Fab-DTPA has potential to target HER2 receptor. It could be radiolabelled with Ga-68 for PET imaging and Lu-177 for targeted therapy. Citation Format: Jaya Shukla, Yogesh Rathore, Komalpreet Kaur, Santosh Irrinky, Rajender Kumar, Amanjit Bal, Bhagwant R Mittal. Radiolabelled Trastuzumab Fab as a theranostic agent for HER2 expressing breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr B043.

Solubility Enhancement and Antioxidant Potential of Silymarin: A Poorly Water-soluble Drug

Background: Silymarin is extracted from the seeds of milk thistle (Silybum marianum), exhibits antioxidant properties, and is considered to treat numerous hepatic ailments like chronic liver disease, cirrhosis, and chemical degradation of liver cells and prevent hepatotoxicity from various drugs. Objective: The objective of the present study was to preclude the problem of poor dissolution of the relatively water-insoluble drug by formulating solid dispersions of the drug. Methods: Solid dispersions of silymarin were prepared by solvent evaporation method by using different polymers, i.e., PEG 6000 and poloxamer 407, in various ratios such as 1:2, 1:4 and 1:6. The compatibility of ingredients with the drug was tested by using Differential scanning calorimetry (DSC), X-Ray Diffractometry, and Fourier Transform-Infrared Spectroscopy (FT-IR). The scavenging activity of DPPH (2,2 diphenyl-1-picrylhydrazyl) radical was used to study the antioxidant activity, and an in vitro release study was conducted using phosphate buffer pH 6.8 as dissolution medium followed by the kinetic assessment to study the drug release mechanism. Results: Solid dispersions with different polymers were successfully prepared by the solvent evaporation method. FTIR spectroscopy and DSC showed no chemical interaction between the drug and polymers. Powder XRD analyses of optimized solid dispersions showed a relative decrease in crystallinity compared to the pure drug. The dissolution profile of solid dispersions successfully exhibited 90.78% drug released, and the optimized batch was found to follow Higuchi drug release kinetics with an R2 value of 0.990. Furthermore, the optimized formulation F6 showed higher antioxidant activity compared to pure silymarin and ascorbic acid. Conclusion: The elevated bioavailability, as well as absorption, consistently regulates the specific therapeutic effect of the water-insoluble drug. The specific response of silymarin to various bodily functions upgrades various activities like anti-aging effects, anti-cancer, antihypertensive, etc. Solid dispersion of drugs with good aqueous solubility results in a decrease in dose frequency and enhanced specificity of the drug mechanism.

An electrochemical voltammetric response of Hg2+ and Pb2+ ions using polyaniline-benzothiazole composite modified GCE electrode: Synthesis, characterization and quantum chemical calculation

An efficient electrochemical sensor based on polyaniline-benzothiazole [(3,5-bis (benzo[d]thiazol-2-yl)-[1,1–biphenyl]-4-ol)] (PAni-BEN) composite was designed and synthesized in this study, and it was employed as an electrochemical sensor to detect Hg2+ and Pb2+ ions with good selectivity and sensitivity. Fourier transform-infrared spectroscopy, UV–Vis spectroscopy, scanning electron microscopy, and energy dispersive X-ray analysis spectroscopy were employed to examine the morphology and structure of the produced composite. The electrochemical characteristics of the electrode modifiers were evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Also, they were employed to perform both individual and simultaneous sensing studies of various metal ions using the differential pulse voltammetry technique (DPV) in a different supporting electrolyte (acetate buffer (pH 5), phosphate buffer (pH 7), and 0.1 M HCl) mediums. The PAni-BEN composite modified GCE sensor shows remarkable selectivity and sensitivity towards Hg2+ and Pb2+ ions over the other heavy metal ions in 1 to 24.84 µM, respectively. The limits of detection (S/N = 3) were 1 nM and 4.6 nM for Hg2+ and Pb2+ ions. Density Functional Theory (DFT) was used in the present study to accomplish the adsorption mechanism of the suggested sensors. The DFT calculation demonstrated that the PAni-BEN composite was formed with a lower band gap energy than BEN and DD PAni. These findings showed that the suggested sensor (PAni-BEN), which may used to detect Hg2+ and Pb2+ ions, had the lowest detection limit in the acetate buffer medium compared to the proposed electrolyte medium.

Preparation and characterization of novel mirabegron salts for sustaining dissolution and improving diffusion/permeability

Overactive bladder (OAB) is a disturbing and distressing condition associated with severe adverse consequences, such as depression, social isolation and participation restriction. Mirabegron (Mira.), used for the treatment of OAB is a BCS class-III drug that displays inconsistent bioavailability upon oral administration depending on dose, gender, and food intake. The present investigation aimed to synthesize sustained release/slow dissolving salts of Mira. to overcome its food intake dependent erratic bioavailability and to improve its permeability. The solvent evaporation method was used to prepare novel slow dissolving salts of Mira. by reacting it with various long-chain fatty acids (stearic acid, palmitic acid, myristic acid, and lauric acid). The differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) studies suggested the genesis of a new crystalline phase due to a reaction between Mira. and fatty acids. Fourier-transform infrared spectroscopy (FTIR) and 1H Nuclear magnetic resonance (NMR) studies confirmed the transfer of proton between the primary amine group (-NH2) of Mira. and carboxylic acid group (-COOH) of fatty acids and thus the formation of salts. The prepared salts have significantly slower dissolution than Mira. in 6.8 pH phosphate buffer. The equilibrium solubility of prepared salts were lower than Mira in 6.8 pH phosphate buffer and water. The in-vitro diffusion study using the Franz diffusion cell proved better permeability of the prepared salts compared to Mira.

Challenges and Strategies to develop RP-HPLC Method of L-Arginine with Polyphenolic compounds

While developing a method of RP-HPLC for a new compound or combination of drugs simultaneously, many challenges are faced by the researcher pertaining to effective elution and sufficient resolution of a mixture of compounds. Many factors come into the picture, which reflects the ultimate elution of chemical compounds. Factors like the physicochemical properties of chemical compounds, the chemical nature of the mobile phase, instrumental factors, and experimental conditions play crucial roles in RP-HPLC method development. This research article discusses the challenges faced while developing a method of L-Arg along with polyphenolic compounds. Both the compounds have contrasting solubility profiles as L-Arg is soluble in water but PIC is soluble in organic solvents. Strategies were used to develop RP-HPLC of this combination with mobile phases like acetonitrile, orthophosphoric acid, methanol, and potassium dihydrogen phosphate buffer of pH 2.6. The present article provides an insightful approach to develop a new RP-HPLC method for a combination of compounds having related physicochemical characteristics.