An extended release aqueous suspension composition of methylphenidate or salts thereof, is provided. The extended release aqueous suspension of methylphenidate or salts has pH below 3.5 and exhibit excellent storage stability when tested for impurity and potency of methylphenidate. The suspension also comprises immediate release and sustained release components of methylphenidate or salts thereof. Following administration of a single dose of the extended release aqueous suspension of methylphenidate, a therapeutically effective amount of methylphenidate is reached in less than an hour, provides release profile of at least 12 hours and its vivo release is characterized by one single main plasma concentration peak.
