Disclosed is a process to produce an improved formulated vinylidene chloride polymer comprising a solid inorganic additive and producing improved vinylidene chloride polymer film products. The process includes adding the inorganic solid additive (such as magnesium hydroxide and/or other inorganic acid scavenger) in a dispersion of a liquid, such as a liquid plasticizer or stabilizer to improve distribution through the polymer and reduction of relatively large sized particles or agglomerates in the polymer and film.