CONCERTA (methylphenidate HCl) Extended-release Tablets CII
CONCERTA is a central nervous system (CNS) stimulant. CONCERTA is available
in two tablet strengths. Each extended-release tablet for once-a-day oral
administration contains 18 or 36 mg of methylphenidate HCl USP and is
designed to have a 12-hour duration of effect. Chemically, methylphenidate
HCl is d,l (racemic) methyl a-phenyl-2-piperidineacetate hydrochloride.
Its empirical formula is C14H19NO2HCl.
Methylphenidate HCl USP is a white, odorless crystalline powder. Its
solutions are acid to litmus. It is freely soluble in water and in methanol,
soluble in alcohol, and slightly soluble in chloroform and in acetone.
Its molecular weight is 269.77.
CONCERTA also contains the following inert ingredients: butylated hydroxytoluene,
carnauba wax, cellulose acetate, hydroxypropyl methylcellulose, lactose,
phosphoric acid, poloxamer, polyethylene glycol, polyethylene oxides,
povidone, propylene glycol, sodium chloride, stearic acid, succinic acid,
synthetic iron oxides, titanium dioxide, and triacetin.
System Components and Performance
CONCERTA uses osmotic pressure to deliver methylphenidate HCl at a
controlled rate. The system, which resembles a conventional tablet in
appearance, comprises an osmotically active trilayer core surrounded by
a semipermeable membrane with an immediate-release drug overcoat. The
trilayer core is composed of two drug layers containing the drug and excipients,
and a push layer containing osmotically active components. There is a
precision-laser drilled orifice on the drug-layer end of the tablet. In
an aqueous environment, such as the gastrointestinal tract, the drug overcoat
dissolves within one hour, providing an initial dose of methylphenidate.
Water permeates through the membrane into the tablet core. As the osmotically
active polymer excipients expand, methylphenidate is released through
the orifice. The membrane controls the rate at which water enters the
tablet core, which in turn controls drug delivery. The biologically inert
components of the tablet remain intact during gastrointestinal transit
and are eliminated in the stool as a tablet shell along with insoluble