Described herein are pharmaceutical formulations for the treatment of hypercholesterolemia, comprising nanoparticles having a polymeric hydrophobic core which is associated with an inhibitor of PCSK9. The inhibitor may be EGF-A, EGF-B, or an siRNA. Preferred polymers include chitosan. The nanoparticle may further include a hydrophilic shell coating the core. The core may be porous.