Kinetic parameters Free-GHTHase PEG-GHTHase
Enzyme injection  NADH Injection Enzyme injection  NADH Injection
Initial Drug Conc. (U/ml)* 0.698 - 0.384 -
Biological half-life time (h)** 10 9.6 12.2 12
Elimination Constant (U/h)*** 0.016 0.016 0.010 0.016
* IEC was expressed by the of initial enzyme activity U per volume of blood plasma of
Zealand white rabbit (Approximately 85 ml/1.5 kg body weight).
** BT1/2 was the time (h), which the enzyme retains about 50 % of its original activity.
*** Elimination constant was expressed by the rate of enzyme removal from the body
Table 3: in vivo Pharmacokinetic properties of free and PEG-GHTHase using New
Zealand Rabbits.