Hydrocodone and
Oxycodone are both narcotic pain relievers. However Oxycodone is about 2.5x stronger than Hydrocodone. Oxycodone is also available in MUCH larger doses (up to 80mg) than Hydrocodone.
Oxycodone is a schedule II controlled substance (CII)
Hydrocodone is a schedule III controlled substance (CIII)
When you say 'class 3' I am assuming you are in the US and actually mean Schedule III.
In the US, drugs are 'scheduled' in accordance to their risk of abuse vs medicinal value by the DEA.
CIII drugs are defined as having:
"(A) A potential for abuse less than the drugs or other substances in schedules I and II.
(B) A currently accepted medical use in treatment in the United States.
(C) Abuse of the drug or other substance may lead to moderate or low physical dependence
or high psychological dependence."
See this link for a further explanation of all schedules CI through CIV:
http://en.wikipedia.org/wiki/Controlled_substance
You can view a complete list of controlled substances here:
http://www.deadiversion.usdoj.gov/sc...phabetical.htm