Spectrophotometric Determination of Some Non-Sedating Antihistamines Using Erythrosine B

Table 1

The studied orders of addition of reactants.

Order of addition	𝜆max (nm)	Absorbance at 𝜆max
Drug—buffer—dye	546	0.647
Drug—dye—buffer	550	0.776
Dye—drug—buffer	544	0.637
Dye—buffer—drug	543	0.602

EBS (6 μg/mL) was used as a representative example.