Suitable polymers for the homogeneous formulation of drug/polymer mixtures should be selected to correct the structural and physicochemical nature with a rapid dissolution rate. This study aimed to evaluate a copolymer prepared by the radical polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and a polyhedral oligomeric silsesquioxane (POSS) methacrylate bearing an ethyl (C₂H₅) group (MPC-ran-C₂H₅-POSS) as a carrier for the solid formulation of paclitaxel (PTX). A single-phase homogeneous formulation of PTX with the mixture of the MPC-ran-C₂H₅-POSS and polyvinylpyrrolidone (PVP) was prepared by a solvent method. The formulation of MPC-ran-C₂H₅-POSS/PVP/PTX enhanced the dissolution rate and the dissolved amount (approximately 90% within 40 min) without precipitation. The X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) analysis confirmed the presence of PTX as an amorphous state. The amphiphilic nature of the MPC-ran-C₂H₅-POSS contributed to enhancing the aqueous solubility of PTX. The new formulation is applicable for solid dispersion technique via the supersaturation of PTX in an aqueous media.