Acta Pharm. 52 (2002) 171-179

Bioadhesive controlled release metronidazole vaginal tablets^*

AMAL HASSAN EL-KAMEL,^1*  MAGDA SAMIR SOKAR,²  VIVIANE FAHIM NAGGAR² 
and   SAFAA SALAH AL GAMAL²

amalelkamel@yahoo.com

¹Department of Pharmaceutics, Faculty of Pharmacy, King Saud University, Kingdom of Saudi Arabia
²Department of Pharmaceutics, Faculty of Pharmacy, Alexandria University, Egypt

Metronidazole vaginal tablets were prepared by direct compression using four single bioadhesive polymers namely: sodium carboxymethylcellulose (NaCMC), methylcellulose (MC), hydroxypropylmethylcellulose (HPMC) and Carbopol 934, and HPMC/NaCMC mixture in different ratios. The drug-polymer ratio was 1:4. The drug dissolution rate at pH 4.8 from single polymer tablets followed the sequence: MC > Carbopol > Na CMC > HPMC, while in water it was: MC > NaCMC > Carbopol > HPMC. Drug dissolution rate from tablets containing NaCMC:HPMC (2:1) was an intermediate between that from either NaCMC or HPMC tablets.
Swelling studies indicated an increase in swelling indices with time at 37 ^oC for both blank and medicated tablets. Measurement of mucoadhesion gave the same rank order for both medicated and blank tablets namely: NaCMC > Carbopol > HPMC > MC. Adhesion behaviour of tablets prepared from NaCMC:HPMC (2:1) was intermediate between that of NaCMC and HPMC tablets. Generally, the presence of drug increased the adhesiveness of the formulation while that of the mucolytic agent decreased it.

Keywords: bioadhesion, cellulosic polymers, Carbopol, swelling, release study, mucolytic agent