THE BIOAVAILABILITY OF TETRACYLINE TABLETS MANUFACTURIED BY PHARMACEUTICAL FACTORIES IN CHINA

The dissolution rates of 28 tetracycline tablet samples obtained from various factories were determined. The absorption of six of the 28 samples were determined using tetracycline solution as reference standard in 18 volunteers by urine test for 72 hours. The absorption of two of the six samples were also determined in ten volunteers by plasma test for 12 hours. The observed absorption of the six samples showed distinct statistical difference. The availabilities of the six samples were 87.40%, 81.40%, 79.08%, 75.15%, 57.05% and 39.15% respectively. The correlation between bioavailability and dissolution rate was not significant. A dissolution rate limit was suggested.