(a) The following state agencies shall participate in the prescription drug bulk purchasing program authorized under this chapter.
(1) State Department of State Hospitals.
(2) Department of Corrections.
(3) Department of the Youth Authority.
(4) State Department of Developmental Services.
(b) Any state, district, county, city, municipal, or public agency governmental entity, other than a state entity specified in subdivision (a), may elect to participate in the coordinated purchasing program.