DETERMINATION OF ARGININE AND ASCORBIC ACID IN EFFERVESCENT TABLETS BY MULTIDIMENSIONAL CHROMATOGRAPHY

This paper describes a fast and direct method for quantification of arginine and ascorbic acid (vitamin C) in effervescent tablets. HPLC-UV multidimensional chromatography (RP18 and cyanopropyl columns) was developed and validated. Phosphate buffer 10 mMpH 3.4 was used as mobile phase. Satisfactory resolution between the drugs was obtained with analysis time less than 8.0 min. Method was linear in the ranges of 140-320 mg.mL-1 and 240-560 mg.mL-1 for arginine and ascorbic acid, respectively. Precision showed RSD <2.0%. Recovery was 99.5% and 100.0% for arginine and ascorbic acid, respectively. Robustness was confirmed through factorial analysis 22 (pH and mobile phase flow rate as factors).This paper describes a fast and direct method for quantification of arginine and ascorbic acid (vitamin C) in effervescent tablets. HPLC-UV multidimensional chromatography (RP18 and cyanopropyl columns) was developed and validated. Phosphate buffer 10 mMpH 3.4 was used as mobile phase. Satisfactory resolution between the drugs was obtained with analysis time less than 8.0 min. Method was linear in the ranges of 140-320 mg.mL-1 and 240-560 mg.mL-1 for arginine and ascorbic acid, respectively. Precision showed RSD <2.0%. Recovery was 99.5% and 100.0% for arginine and ascorbic acid, respectively. Robustness was confirmed through factorial analysis 22 (pH and mobile phase flow rate as factors)

Stability-indicating method for the analysis of amorolfine and its N-oxide degradation product

This work aimed to validate a stability-indicating method for determining amorolfine (AMF) in topical formulations by HPLC-DAD. The tailing factor, capacity factor, and theoretical plates were optimized by employing the desirability function. AMF was quantified in a hydrophilic formulation produced in our laboratory and Loceryl® cream and lacquer. Reverse-phase HPLC method with detection at 218 nm showed selectivity (peak purity&gt; 995), robustness (RSD &lt;2.0%), linearity (35–325 μg.mL-1), accuracy (≈100.0%), precision (RSD &lt;2.0%) and limit of quantitation of 750 ng.mL-1. Forced degradation of AMF in an oxidative medium containing hydrogen peroxide resulted in a degradation product that was purified and identified as an N-oxide. The degradation kinetics was pH-dependent

Bombesin receptor-targeted liposomes for enhanced delivery to lung cancer cells

Background: Gastrin-releasing peptide is a member of the bombesin family of peptides. Its cognate receptor, GRPR, is widely expressed in cancers of the lung, pancreas and ovaries. GRP is an autocrine growth factor in small cell lung cancer, which has very poor patient outcomes. High affinity antagonist peptides have been developed for in vivo cancer imaging. In this report we decorated pegylated liposomes with a GRPR antagonist peptide and studied its interaction with and accumulation within lung cancer cells. Results: An N-terminally cysteine modified GRPR antagonist (termed cystabn) was synthesised and shown to inhibit cell growth in vitro. Cystabn was used to prepare a targeted 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE-PEG2000) lipid conjugate that was formulated into liposomes. The liposomes displayed desirable colloidal properties and good stability under storage conditions. Flow cytometric and microscopic studies showed that fluorescently labelled cystabn-decorated liposomes accumulated more extensively in GRPR over-expressing cells than matched liposomes that contained no cystabn targeting motif. Conclusion: The use of GRPR antagonistic peptides for nanoparticle targeting has potential for enhancing drug accumulation in resistant cancer cells

DETERMINATION OF ARGININE AND ASCORBIC ACID IN EFFERVESCENT TABLETS BY MULTIDIMENSIONAL CHROMATOGRAPHY

This paper describes a fast and direct method for quantification of arginine and ascorbic acid (vitamin C) in effervescent tablets. HPLC-UV multidimensional chromatography (RP18 and cyanopropyl columns) was developed and validated. Phosphate buffer 10 mMpH 3.4 was used as mobile phase. Satisfactory resolution between the drugs was obtained with analysis time less than 8.0 min. Method was linear in the ranges of 140-320 mg.mL-1 and 240-560 mg.mL-1 for arginine and ascorbic acid, respectively. Precision showed RSD &lt;2.0%. Recovery was 99.5% and 100.0% for arginine and ascorbic acid, respectively. Robustness was confirmed through factorial analysis 22 (pH and mobile phase flow rate as factors).This paper describes a fast and direct method for quantification of arginine and ascorbic acid (vitamin C) in effervescent tablets. HPLC-UV multidimensional chromatography (RP18 and cyanopropyl columns) was developed and validated. Phosphate buffer 10 mMpH 3.4 was used as mobile phase. Satisfactory resolution between the drugs was obtained with analysis time less than 8.0 min. Method was linear in the ranges of 140-320 mg.mL-1 and 240-560 mg.mL-1 for arginine and ascorbic acid, respectively. Precision showed RSD &lt;2.0%. Recovery was 99.5% and 100.0% for arginine and ascorbic acid, respectively. Robustness was confirmed through factorial analysis 22 (pH and mobile phase flow rate as factors)

Stability-indicating method for the analysis of amorolfine and its N-oxide degradation product

This work aimed to validate a stability-indicating method for determining amorolfine (AMF) in topical formulations by HPLC-DAD. The tailing factor, capacity factor, and theoretical plates were optimized by employing the desirability function. AMF was quantified in a hydrophilic formulation produced in our laboratory and Loceryl® cream and lacquer. Reverse-phase HPLC method with detection at 218 nm showed selectivity (peak purity&gt; 995), robustness (RSD &lt;2.0%), linearity (35–325 μg.mL-1), accuracy (≈100.0%), precision (RSD &lt;2.0%) and limit of quantitation of 750 ng.mL-1. Forced degradation of AMF in an oxidative medium containing hydrogen peroxide resulted in a degradation product that was purified and identified as an N-oxide. The degradation kinetics was pH-dependent

STABILITY-INDICATING METHOD FOR DETERMINATION OF TIZANIDINE HYDROCHLORIDE IN PHARMACEUTICAL LC-CAD METHOD USING CHEMOMETRIC APPROACH

A new LC method for tizanidine hydrochloride in tablet dosage form using a charged aerosol detector (CAD) is described. The influence of various parameters on chromatographic system was investigated by factorial designs and Derringer's desirability. Chromatographic conditions were: mobile phase constituted of acetonitrile and ammonium acetate buffer 17 mM (60:40; v/v), column oven at 39 °C and flow rate 0.8 mL.min-1 performed in on Acclaim Trinity P1 column UV at 230 nm. Thus, it was possible to validate a simple method to assay the tizanidine and its counter-ion in three formulations (drug reference, generic and manipulated). Method showed specificity when challenged by forced degradation and excipients. Finally, the method was compared with USP monograph method demonstrating equivalence in assay evaluation

Functional Recovery Caused by Human Adipose Tissue Mesenchymal Stem Cell-Derived Extracellular Vesicles Administered 24 h after Stroke in Rats

Ischemic stroke is a major cause of death and disability, intensely demanding innovative and accessible therapeutic strategies. Approaches presenting a prolonged period for therapeutic intervention and new treatment administration routes are promising tools for stroke treatment. Here, we evaluated the potential neuroprotective properties of nasally administered human adipose tissue mesenchymal stem cell (hAT-MSC)-derived extracellular vesicles (EVs) obtained from healthy individuals who underwent liposuction. After a single intranasal EV (200 &micro;g/kg) administered 24 h after a focal permanent ischemic stroke in rats, a higher number of EVs, improvement of the blood&ndash;brain barrier, and re-stabilization of vascularization were observed in the recoverable peri-infarct zone, as well as a significant decrease in infarct volume. In addition, EV treatment recovered long-term motor (front paws symmetry) and behavioral impairment (short- and long-term memory and anxiety-like behavior) induced by ischemic stroke. In line with these findings, our work highlights hAT-MSC-derived EVs as a promising therapeutic strategy for stroke