Tetracycline inhibition zone diameters

Sample no. (n = 10)

Tetracycline disc (30 µg)

Ch/VitC

Ch/VitC/FeEDTA

Ch/VitC/FeEDTA/T

Ch/VitC/FeEDTA/T/HA

Ch/VitC/T/HA

Average ± standard deviation

26.44 ± 0.28

0

0

23.67 ± 0.55

20.09 ± 1.63

22.80 ± 0.64