Absorption of recombinant human granulocyte colony-stimulating factor (rhG-CSF) and blood leukocyte dynamics following intranasal administration in rabbits.

Absorption of recombinant human granulocyte colony-stimulating factors (rhG-CSF) following intranasal administration of aqueous preparations containing rhG-CSF with or without dimethyl-beta-cyclodextrin was investigated. It was found that rhG-CSF was absorbed and the total leukocyte numbers in peripheral blood markedly increased after intranasal instillation of rhG-CSF solution (pH 4) without excipients. Simultaneously administered dimethyl-beta-cyclodextrin enhanced nasal absorption of rhG-CSF. Consequently, serum rhG-CSF concentrations and total leukocyte numbers were greatly increased.