[Rectal absorption of phenobarbital in children as affected by different vehicles].

68 infants received 7--15 mg phenobarbital and sodium-phenobarbital/kg body weight by suppositories of different melting-points and hydroxyl-values (Witepsol H 12, W 35, E 76). The kinetic analysis of the serum concentration curve shows that the rate of rectal absorption is significantly increased if sodium-phenobarbital instead of phenobarbital is applied. The absorption rate is faster using suppositories with a lower melting-point (32.5 degrees C) compared to suppositories with a higher one (37.5 degrees C). Increasing the amount of hydroxyl values in the vehicle the absorption rate of phenobarbital becomes faster. Comparing the area under the serum concentration curve after intravenous and rectal application in 8 infants the absorption ratio was 74%.