What is in Tramadol
Tramadol contains tramadol hydrochloride as the active pharmaceutical ingredient, which is a centrally acting synthetic analgesic with a dual mechanism of action: weak mu-opioid receptor agonism and inhibition of norepinephrine and serotonin reuptake. 1
Chemical Composition and Formulation
The active ingredient is tramadol hydrochloride, with the chemical name (±)cis-2-[(dimethylamino)methyl]-1-(3-methoxyphenyl) cyclohexanol hydrochloride, molecular formula C₁₆H₂₅NO₂•HCl, and molecular weight of 299.8. 1
Each standard oral tablet contains 50 mg of tramadol hydrochloride as the active ingredient. 1
Inactive Ingredients
The tablets also contain the following inactive excipients: 1
- Hypromellose
- Lactose monohydrate
- Magnesium stearate
- Microcrystalline cellulose
- Polyethylene glycol
- Polysorbate 80
- Pregelatinized starch
- Sodium starch glycolate
- Titanium dioxide
Pharmacological Characteristics
Tramadol is a racemic mixture of two enantiomers that work synergistically through complementary mechanisms: 2, 3
- (+)-Tramadol: Acts as a mu-opioid receptor agonist and inhibits serotonin reuptake 3
- (-)-Tramadol: Inhibits norepinephrine reuptake 3
The dual mechanism provides analgesic efficacy approximately one-tenth as potent as morphine, with the advantage of reduced respiratory depression and lower dependence potential compared to traditional opioids. 4, 5
Physical Properties
Tramadol hydrochloride appears as a white, bitter, crystalline, odorless powder that is readily soluble in water and ethanol, with a pKa of 9.41. 1