PSK is highly soluble in water and its bioavailability is by the oral route. Animal testings with radio-labelled PSK show that PSK is partially degraded in the gut to smaller molecules which then appear in the blood within 2 hrs in mice, I hrs in rats and 1-2 hrs in rabbits after oral ingestion.
By 4hrs, larger molecules are found in the blood3. In cancer-bearing animals, PSK is distributed in the bone marrow, salivary gland, brain, liver, spleen, pancreas and tumour tissues. About 70% of PSK is excreted in expired air while 15-20% is excreted in the urine and 0.8% in the bile4. About 11.5% of orally administered PSK accumulates in the macrophages in the liver and the spleen4.
PSK does not interact with other drugs nor affect drug-metabolizing enzyme activities in the liver5.