Concentration profiles of spherical solutes both in a slit pore and in a bulk are obtained for a wide range of solute concentrations by employing the Gibbs ensemble Monte Carlo scheme, in which two kinds of stochastic perturbations are performed with a random displacement of solutes and random interchanges of solutes. In principle, the solute particle is in motion due to a combination of Brownian movement and convective displacement by the surrounding fluid. The hydrodynamic coefficient for diffusive hindrance factor applied in this study is the recently provided result using an asymptotic matching technique. The long-range electrostatic interactions between the particle and the adjacent wall and between the particles are determined by solving with the singularity method, which provides accurate solutions to the linearized Poisson-Boltzmann equation. The obtained concentration profiles indicate that, whether both solutes and pores are uncharged or of like charge, solute-solute interactions promote concentration buildup near the pore wall. Due to the interplay of solute-solute and solute-wall interactions associated with repulsive energy, the hindered diffusion coefficient of charged system is predicted to increase with increasing solute concentration or ionic strength of solution, for a given relative pore size. Present investigation with the Gibbs ensemble Monte Carlo has made it possible to provide a proper estimation for the charged systems at non-dilute concentrations.