Question

True or False With Reasons.
1.The phenyl acyl substitutent in cephalosporins contribute to increased acid stability of lactam ring.
2.Tetracyclines cannot be administered with multivalent ion rich antacids​

Answer 1

Answer for the 2nd question:

2]  Stereochemistry of tetracyclines is very complex. Vignan Pharmacy College,Vadlamudi,Guntur.  The tetracycline's are incompatible with co-administered, multivalent ion-rich antacids and with hematinics and concomitant consumption of daily products rich in calcium ion also is contraindicated