Abstract: The in-vitro adsorption of chlorpheniramine maleate on activated charcoal, magnesium trisilicate, talc powder and magnesium carbonate have been studied at 37oC and pH = 5.0 using the Batch method. Both the Langmuir and Freundlich parameters were determined for each adsorbent and their values used in determination of adsorption capacities of each. The results show that the adsorption capacities increased in the order Activated carbon > Magnesium trisilicate > magnesium stearate > Talc power. This in-vitro study indicates that some chlorpheniramine maleate may be lost when it is administered concomitantly with pharmaceutical adsorbents.