Physical and structural stability of the monoclonal antibody, trastuzumab (Herceptin®), intravenous solutions

Design and Characterization of Paclitaxel-Loaded Polymeric Nanoparticles Decorated With Trastuzumab for the Effective Treatment of Breast Cancer

The aim of the study was to design and formulate an antibody-mediated targeted, biodegradable polymeric drug delivery system releasing drug in a controlled manner to achieve a therapeutic goal for the effective treatment of breast cancer. Antibody-mediated paclitaxel-loaded PLGA polymeric nanoformulations were prepared by the solvent evaporation method using different experimental parameters and compatibility studies. The optimized formulations were selected for in vitro and in vivo evaluation and cytotoxicity studies. The in vitro drug release studies show a biphasic release pattern for the paclitaxel-loaded PLGA nanoparticles showing a burst release for 24 h followed by an extended release for 14 days; however, a more controlled and sustained release was observed for antibody-conjugated polymeric nanoparticles. The cytotoxicity of reference drug and paclitaxel-loaded PLGA nanoparticles with and without antibody was determined by performing MTT assay against MCF-7 cells. Rabbits were used as experimental animals for the assessment of various in vivo pharmacokinetic parameters of selected formulations. The pharmacokinetic parameters such as C_max (1.18–1.33 folds), AUC_0-t (39.38–46.55 folds), MRT (10.04–12.79 folds), t_1/2 (3.06–4.6 folds), and V_d (6.96–8.38 folds) have been increased significantly while clearance (4.34–4.61 folds) has been decreased significantly for the selected nanoformulations as compared to commercially available paclitaxel formulation (Paclixil^®). The surface conjugation of nanoparticles with trastuzumab resulted in an increase in in vitro cytotoxicity as compared to plain nanoformulations and commercially available conventional brand (Paclixil^®). The developed PLGA-paclitaxel nanoformulations conjugated with trastuzumab have the desired physiochemical characteristics, surface morphology, sustained release kinetics, and enhanced targeting.

Preparation of intravenous chemotherapy bags: evaluation of a dose banding approach in an Italian oncology hospital

Introduction

Dose banding is an original approach that manages intravenous (IV) chemotherapy preparation by generating on a weekly basis a series of bags containing scaled dosages of the active agent. These predetermined, fixed dosage bags are intended to replace the traditional bags prepared daily that contain fully individualized dosages.

Methods

Three different scenarios were examined: (1) the current method of daily preparation of individualized bags at the hospital pharmacy; (2) the weekly preparation at the hospital pharmacy of non-individualized bags containing discrete, predefined doses covering an adequate range of doses (dose banding); (3) the use of commercial ready-to-use bags based on the same approach of dose banding. The objective of this study was to compare these three different approaches in terms of cost per patient. We considered five cancer drugs (gemcitabine, oxaliplatin, paclitaxel, trastuzumab and 5-fluorouracil) that were suitable for the dose ranging approach. Appropriate dose bands for these five agents were identified. Costs were estimated for each of the three approaches.

Results

A total of 13,490 fully individualized bags were studied, which corresponded to the real bags prepared at our institution for these five agents in 2018. Dose banding was predicted to determine savings ranging from €10,998 (-0.84%) for trastuzumab to €169,429.60 (-8.39%) for paclitaxel.

Conclusion

The introduction of dose banding can determine economic savings along with other advantages, such as improved work conditions, management reorganization and containment of waste. The pharmaceutical industry can hopefully support these experiences by producing ready-to-use bags in predetermined dosages.

Conformational characterization of a novel anti-HER2 candidate antibody

Regulatory agencies establish that a broad physicochemical and biological characterization is necessary for the evaluation of comparability between a biosimilar candidate product and a reference commercial drug. Between them, conformational characterization of proteins is of vital importance to determine its folding and biological functions. In this work, the conformational features of a novel monoclonal antibody (called 5G4) were evaluated by means of circular dichroism spectroscopy and fluorescence. Secondary structure and thermal stability of mAbs were determined by circular dichroism in the far ultraviolet, while three-dimensional folding of proteins was analyzed by both circular dichroism in the near ultraviolet and intrinsic tryptophan fluorescence. In all experiments, Herceptin (Roche) was used as control. Both antibodies showed a composition of secondary structure predominantly of β-sheets (55–56%) and thermal stability of ~ 75°C, suggesting structural similarity. The three-dimensional folding of proteins was also similar due to the absorption spectra of the aromatic residues and the emission wavelength maxima by fluorescence were comparable. The values of the fluorescence attenuation constant (Stern-Volmer constant) for increasing concentrations of acrylamide were also similar, suggesting a degree of exposure of tryptophan residues similar, although it was slightly decreased for Herceptin. Our data permit to consider that 5G4 monoclonal antibody showed similar conformational characteristics when compared with Herceptin.

Influence of Parathyroid Hormone-Loaded PLGA Nanoparticles in Porous Scaffolds for Bone Regeneration

Biodegradable poly(lactide-co-glycolide) (PLGA) nanoparticles, containing human parathyroid hormone (PTH (1–34)), prepared by a modified double emulsion-solvent diffusion-evaporation method, were incorporated in porous freeze-dried chitosan-gelatin (CH-G) scaffolds. The PTH-loaded nanoparticles (NPTH) were characterised in terms of morphology, size, protein loading, release kinetics and in vitro assessment of biological activity of released PTH and cytocompatibility studies against clonal human osteoblast (hFOB) cells. Structural integrity of incorporated and released PTH from nanoparticles was found to be intact by using Tris-tricine SDS-PAGE. In vitro PTH release kinetics from PLGA nanoparticles were characterised by a burst release followed by a slow release phase for 3–4 weeks. The released PTH was biologically active as evidenced by the stimulated release of cyclic AMP from hFOB cells as well as increased mineralisation studies. Both in vitro and cell studies demonstrated that the PTH bioactivity was maintained during the fabrication of PLGA nanoparticles and upon release. Finally, a content of 33.3% w/w NPTHs was incorporated in CH-G scaffolds, showing an intermittent release during the first 10 days and, followed by a controlled release over 28 days of observation time. The increased expression of Alkaline Phosphatase levels on hFOB cells further confirmed the activity of intermittently released PTH from scaffolds.