INTRODUCTION. The number of diabetic patients increases all over the world. All types of diabetes cause relative or absolute deficiency of insulin and its reduced peripheral effectiveness and lead to microand macroangiopathy. A considerable group of diabetic patients requires constant or periodic supplementation of insulin. Currently most of insulin preparations are composed of human insulin, produced on major scale with genetic engineering methods. The aim of the study was to compare biological availability of two insulin preparations administered intravenously: a new recombinant insulin by BIOTON Sp. z o.o. (Gensulin) and reference recombinant insulin by NovoNordisk (Human Actrapid).
MATERIAL AND METHODS. This open, randomized, cross-over study included 18 healthy male volunteers (mean age 32.94 ± 5.21 years, height 182.5 ± 4.81 cm, weight 80.94 ± 7.93). The study was composed of two treatment periods divided with a one week washout period. All patients were randomized to receiving either recombinant insulin (Gensulin) or reference insulin at the first stage of the study and after washout period the treatment groups were crossed-over. Insulin injection (100 min) was performed with the method of euglycaemic clamp; simultaneous injection of insulin and 20% glucose. The effectiveness of each preparation was assessed on the basis of calculating the amount of glucose needed for one unit of insulin during last 20 minutes of the injection. Insulin concentration, C peptide and serum potassium were additionally assessed in planned time intervals.
RESULTS
1. The analysis of results showed general similarities between new tested recombinant insulin (Gensulin) and reference insulin (Actrapid).
2. During the time period of insulin injection (0–100 min) in most of the study participants serum concentration (pmol/l) of Gensulin was slightly higher than concentration of Actrapid.
3. Serum glucose (mmol/l) was similar in both tested groups and remained stable during the course of insulin injection.
4. There were no statistically significant differences in mean velocity of glucose injection (mg/kg/min) during last 20 minutes of insulin injection.
5. Mean insulin concentration (i.u./l) in two last measurements during the injection were not statistically different.
6. There were no statistically significant differences in C peptide concentration (pmol/l) during the test.
7. There were no statistically significant differences in pharmacokinetic parameters (half-elimination time and AUC_100-140).
CONCLUSIONS. The results of the study suggest that recombinant insulin (Gensulin, BIOTON) is bioequivalent with reference recombinant insulin (Actrapid, NovoNordisk).