Items Betahistine
dihydrochloride
Etilefrine
hydrochloride
Linearity range (μg/ml )
Apparant molar absorptivity* (mol-1 cm-1)
Sandell’s sensitivity (μg/ml per 0.001 A)
Regression equation :
Intercept (a)
Slope (b)
Correlation coefficient (r)
Variance
0.25 -  7
4.76 x 104
2.28 x 10-2
0.189
0.107
0.9999
0.602
3 - 13
1.51 x 104
6.92 x 10-3
- 9.05 x 10-5
0.069
0.9998
0.719
*calculated on the basis of the molecular weight of the drug
Table 2: Spectral data for determination of betahistine dihydrochloride and etilefrine hydrochloride using fixed time method.