Man, Lowe's website always blows....
Basically, that <might> be the right stuff, or it might not be. Particle board and MDF are different beasts, but warehouse store lumber sections often lump them together. True MDF is much preferred over plain old particle board...It tends to be smoother, more square, and more durable than particle board.
MDF uses finer particles and uses more resin to create a much more dense board, whereas particle board uses larger fibers, and has more void space (lower density, more air).
The only way to know if that is the right stuff by going and checking it out. If it is very smooth, and has no "grain" look or fibre look to it, then it's MDF...if you can see the "chips" of wood that make up the board, then it's particle board.
http://en.wikipedia.org/wiki/Particle_boardhttp://en.wikipedia.org/wiki/Medium-density_fibreboardAny "good" lumberyard will have MDF....
Cheers,
Rich