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Eco-friendly stannic oxide nanoparticles functionalized with gallic acid (SnO2/GA NP) were synthesized and employed as a novel photocatalyst for the degradation of citalopram, a commonly prescribed antidepressant drug. SnO2/GA NP were characterized using high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller measurements and X-ray diffraction. A validated RP-HPLC assay was developed to monitor citalopram concentration in the presence of its degradation products. Full factorial design (24) was conducted to investigate the effect of irradiation time, pH, SnO2/GA NP loading and initial citalopram concentration on the efficiency of the photodegradation process. Citalopram initial concentration was found to be the most significant parameter followed by irradiation time and pH, respectively. At optimum conditions, 88.43 ± 0.7% degradation of citalopram (25.00 µg/mL) was obtained in 1 h using UV light (1.01 mW/cm2). Citalopram kinetics of degradation followed pseudo-first order rate with Kobs and t0.5 of − 0.037 min−1 and 18.73 min, respectively. The optimized protocol was successfully applied for treatment of water samples collected during different cleaning validation cycles of citalopram production lines. The reusability of SnO2/GA NP was studied for 3 cycles without significant loss in activity. This approach would provide a green and economic alternative for pharmaceutical wastewater treatment of organic pollutants. Graphical abstract

Ultrafiltration or dialysis was used as sample pretreatment to remove 95% of lactose. Free PRP was separated using SPE, and then total and free PRP were analyzed using HPAEC-PAD (ribitol determination) and a colorimetric assay (phosphorus determination).

In the current study, a molecularly imprinted polymer (MIP)-based potentiometric sensor was fabricated for a label-free determination of recombinant human erythropoietin (rhEPO). The MIP sensor was operated under zero current conditions using tetra-butyl ammonium bromide as a marker ion. A highly ordered rhEPO surface imprinted layer was prepared using 3-aminopropyl triethoxysilane and tetraethoxysilane as a monomer and cross-linker, respectively, under mild reaction conditions. A two-fold increase in the signal output was obtained by polymeric surface minimization (0.5 mm) that allowed more pronounced molecular recognition (imprinting factor = 20.1). The proportion of cross-reactivity was examined using different interfering biomolecules. Results confirmed sensor specificity for both structurally related and unrelated proteins. An ~40% decrease in the response was obtained for rhEPO-β compared to rhEPO-α. The imprinted polymeric surface was evaluated using scanning electron microscopy and Fourier transform infrared spectroscopy. Under the optimal measurement conditions, a linear range of 10.00–1000.00 ng mL−1 (10−10 − 10−8 M) was obtained. The sensor was employed for the determination of rhEPO in different biopharmaceutical formulations. Results were validated against standard immunoassay. Spiked human serum samples were analyzed and the assay was validated. The presence of non-specific proteins did not significantly affect (~8%) the results of our assay. A concentration-dependent linear response was produced in an identical range with detection limit as low as 6.50 ng mL−1 (2.14 × 10−10 M). The facile fabricated MIP sensor offers a cost-effective, portable, and easy to use alternative for biosimilarity assessment and clinical application.

Eco-friendly stannic oxide nanoparticles functionalized with gallic acid (SnO

Molecular size distribution of Haemophilus influenzae type b (Hib) conjugate vaccine is an important indicator for its immunogenicity and stability. Molecular size distribution was evaluated by High-Performance Protein Chromatography on Sepharose CL-4B column, and fractions were pooled. The use of high flow rate, incorporation of a calibration standard with the injected buffer and pooling method yielded a superior assay compared to conventional pharmacopeial method. The pools were analyzed for determination of distribution coefficient (K

Recombinant human myelin basic protein (rhMBP) produced in the milk of transgenic cows was found exclusively associated with milk caseins. This hindered its direct determination without extensive sample pretreatment. Here, a label-free potentiometric immunosensor was developed and validated for the determination of rhMBP. An ion flux was generated under zero-current based on surface blocking of the polymeric membrane ion-selective electrode by anti-hMBP antibody and tetrabutylammonium bromide as a marker ion. The immunosensor was successfully employed in the quantitative determination of hMBP in the range of 0.10-20.00 μg/mL with a limit of detection of 50.00 ng/mL. The applicability of the passive ion flux immunosensor for determination of target analyte in complex matrices was investigated. Downstream purification of rhMBP from the milk of transgenic cows was achieved using cation exchange chromatography, immobilized metal affinity chromatography, and immunoaffinity chromatography. The specificity of the immunosensor along with matrix effect of milk proteins were demonstrated. Results obtained using the rhMBP immunosensor were further cross-validated using an orthogonal testing protocol assembled of RP-HPLC and SE-HPLC. It should be noted that the proposed ion flux immunosensor provided a feasible and specific tool for monitoring rhMBP concentration/purity, immunogenic activity, and stability. Such approach provides an attractive economic alternative to sophisticated biosensors required for in-process quality control of biopharmaceutical products.

In the current study, a molecularly imprinted polymer (MIP)-based potentiometric sensor was fabricated for a label-free determination of recombinant human erythropoietin (rhEPO). The MIP sensor was operated under zero current conditions using tetra-butyl ammonium bromide as a marker ion. A highly ordered rhEPO surface imprinted layer was prepared using 3-aminopropyl triethoxysilane and tetraethoxysilane as a monomer and cross-linker, respectively, under mild reaction conditions. A two-fold increase in the signal output was obtained by polymeric surface minimization (0.5 mm) that allowed more pronounced molecular recognition (imprinting factor = 20.1). The proportion of cross-reactivity was examined using different interfering biomolecules. Results confirmed sensor specificity for both structurally related and unrelated proteins. An ~40% decrease in the response was obtained for rhEPO-β compared to rhEPO-α. The imprinted polymeric surface was evaluated using scanning electron microscopy and Fourier transform infrared spectroscopy. Under the optimal measurement conditions, a linear range of 10.00-1000.00 ng mL

The integration of molecular imprinted polymers (MIPs) with ion selective electrodes (ISE) has been an ideal platform for sensing of biological products. In this work, a facile MIP was constructed over the surface of PVC polymeric membrane using self-assembled dopamine (DA) as a monomer around recombinant human Erythropoietin (rhEPO) as a template. A label free passive ion flux MIP potentiometric sensor was fabricated using tetra butyl ammonium bromide as a marker ion. MIP preparation was optimized for critical factors (monomer concentration and polymerization time) that affect the thickness of the imprinted layer by central composite response surface design. The optimum condition for DA-MIP preparation was found to be 3.79 mg mL−1 DA for 18.14 h with desirability of 0.9919. A highly selective and sensitive potentiometric sensor was obtained by combining membrane surface minimization with superficial imprinting process strategy. The sensor has elicited selectivity for template molecule as confirmed by imprinting factor exceeding 11-fold the values obtained from closely related rhEPO analogues. The imprinted layer surface was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The quantitative determination of rhEPO was established over the range of 1.00–100.00 ng mL−1 (10-9 to 10-11 M) with a limit of detection of 0.33 ng mL−1. The sensor could classify rhEPO-α products in a similar attitude of natural antibodies. The potentiometric sensor was able to quantitate rhEPO in human serum with a limit of detection of 0.50 ng mL−1 and the bioanalytical assay was successfully validated. The proposed MIP biosensor elicited specificity for template recognition and selectivity in biological fluids without the need of immunoaffinity purification. Such approach shall plan the direction towards a portable sensor for doping disclosure in sports cheating.

Environmentally friendly gallic acid coated magnetic nanoparticles (GA-MNP) have been synthesized and evaluated as a novel photocatalyst for degradation of meloxicam; a commonly prescribed nonsteroidal anti-inflammatory drug. The synthesized GA-MNP were characterized using transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and dynamic light scattering. Results showed the formation of core–shell MNP with a mean hydrodynamic diameter of 160.55 ± 5.02 nm and zeta potential of −42.4 ± 1.6 mV. A validated RP-HPLC stability-indicating assay was developed for monitoring of meloxicam concentration in the presence of its degradation products and for determination of the kinetics of degradation. Full factorial design (24) was employed in order to investigate the effects of pH, irradiation time, GA-MNP loading and initial meloxicam concentration on the efficiency of the process. The irradiation time was found to be the most significant parameter followed by initial meloxicam concentration and GA-MNP loading, respectively. At the optimized conditions, increasing GA-MNP loading to 5.00 mg mL−1 demonstrated superior photocatalytic activity when compared to bare MNP and TiO2NP. Meloxicam degradation was found to follow pseudo first order rate kinetics with Kobs and t0.5 of −0.0029 min−1 and 239 min, respectively. The protocol was successfully applied for treatment of incurred water samples collected during various cleaning validation cycles. A percentage degradation of 89.10 ± 0.13% was achieved upon irradiation of samples containing 64.57 ± 0.09 µg mL−1 with UV light (1012 µW cm−2, 8 h) in the presence of 5 mg mL−1 GA-MNP at pH 9.0 ± 0.05. It could be suggested that treatment of wastewaters collected during the cleaning validation of each pharmaceutical product, before pooling into the general waste pool, should improve the efficiency and economics of pharmaceutical wastewater treatment.

Meloxicam is a commonly prescribed nonsteroidal anti-inflammatory drug with analgesic and fever-reducing effects. In this study, photocatalytic degradation of meloxicam in the presence of TiO2 nanoparticles (TiO2NP) was optimized and applied for pharmaceutical wastewater treatment. A validated stability-indicating orthogonal testing protocol (reversed-phase (RP)-HPLC and capillary zone electrophoresis) was developed and validated for monitoring of meloxicam concentration in the presence of its photodegradation products. Fractional factorial design was employed in order to investigate the effects of pH, irradiation time, UV light intensity, TiO2NP loading, and initial meloxicam concentration on the efficiency of the process. The light intensity was found as the most significant parameter followed by irradiation time and concentration, respectively. The most influencing interactions were noted between irradiation time-concentration and irradiation time-light intensity. The kinetics of meloxicam degradation was investigated at the optimum set of experimental conditions. The protocol was successfully applied for treatment of incurred water samples collected during various cleaning validation cycles. A percentage degradation of 77.34 ± 0.02 % was achieved upon irradiation of samples containing 64.57 ± 0.09 μg/mL with UV light (1012 μW/cm(2), 8 h) in the presence of 0.4 mg/mL TiO2NP at pH 9.0 ± 0.05. Treatment of wastewaters collected during the cleaning validation of each product separately rather than the combined waste should result in a significant improvement in the economics of pharmaceutical wastewater treatment. This could be attributed to the relatively small waste volumes and the ability to tailor the experimental conditions to achieve maximum efficiency.