Formulation and Optimization of Diclofenac Sodium Loaded Ethylcellulose Nanoparticles

Abstract Design of experiment (DoE) is a useful time and cost-effective tool for analyzing the effect of independent variables on the formulation characteristics. The aim of this study is to evaluate the effect of the process variables on the characteristics involved in the preparation of Diclofenac Sodium (DC) loaded ethylcellulose (EC) nanoparticles (NP) using Central Composite Design (CCD). NP were prepared by W/O/W emulsion solvent evaporation method. Three factors were investigated (DC/EC mass ratio, PVA concentration, homogenization speed) in order to optimize the entrapment efficiency (EE) and the particle size of NP. The optimal formulation was characterized by Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), and in vitro release. Optimized formulation showed an EE of 49.09 % and an average particle size of 226.83 nm with a polydispersity index of 0.271. No drug-polymer interaction was observed in FTIR and DSC analysis. SEM images showed that the particles are spherical and uniform. The in vitro release study showed a sustained release nature, 53.98 % of the encapsulated drug has been released over 24hours period. This study demonstrated that statistical experimental design methodology can optimize the formulation and the process variables to achieve favorable responses.

Elicitation of Rheumatologist Preferences for the Treatment of Patients with Rheumatoid Arthritis After the Failure of a First Conventional Synthetic Disease-Modifying Anti-Rheumatic Agent.

INTRODUCTION: Rheumatoid arthritis (RA) clinical guidelines do not provide strong recommendations for the choice of disease-modifying anti-rheumatic drugs (DMARD) in patients with an inadequate response to methotrexate (MTX), and only limited evidence is available on factors influencing rheumatologist treatment decisions. We aimed to describe therapeutic preferences after the failure of a first-line strategy of MTX in simulated cases of patients with RA. METHODS: Fictional but realistic case-vignettes (n = 64) of patients with RA and an inadequate response to MTX were developed with a combination of RA-poor prognostic factors and comorbidities. Physicians were presented with eight vignettes and chose the most and least appropriate therapeutic option from the following six options randomly proposed 3 by 3: (1) replacing MTX with another csDMARD; (2) combining MTX with one or more csDMARDs; (3) adding a bDMARD of either TNF inhibitors (TNFi), tocilizumab (TCZ), abatacept (ABA), or rituximab (RTZ). A total of 1605 complete case vignettes were produced and randomly assigned to a representative sample of French rheumatologists. For each vignette, whenever a treatment was preferred, one point was incremented for this treatment; if this treatment was the least desired, one point was removed. Preferences were elicited using a normalized best-worst score. RESULTS: Two hundred and four French rheumatologists participated in the study with each vignette being assessed 20-28 times for a completion rate of 94%. TNFi was the first-choice strategy (80% of vignettes), except in cases with a history of infection and pulmonary comorbidity, where ABA was the first preference (85%). TCZ came third in 83% of the cases. Other options were never preferred and repeatedly yielded negative scores. CONCLUSIONS: We observed a conservative trend with TNFi as the main therapeutic choice for patients with RA and inadequate response to MTX. Preference for bDMARD-based strategies increased with the number of RA-poor prognosis factors, whereas an increase in the number of comorbidities resulted in an increased preference for ABA. Understanding clinical decision-making will be particularly important as the therapeutic landscape for RA continues to evolve.