The percentage of those of Hispanic origin in the United States who were of Mexican background in 2013. Another 9.5 percent were of Puerto Rican background, 3.7 percent Cuban, 3.7 percent Salvadoran, 3.3 percent Dominican and 2.4 percent Guatemalan.
Onset of effects occurs within 30-60 minutes after taking Concerta. After that, duration of action lasts from 8-12 hours. And the average times to reach peak plasma concentrations across all doses of Concerta occur between 6-10 hour s. The average half-life for Concerta in adults is about 3.5 hours.
The Ritalin brand also comes in a formulation that has a duration of eight hours, utilizing biphasic release to make 50 percent of the drug available immediately and 50 percent available through modified release beads. Other brands, such as Concerta, last for up to 12 hours.