The pharmacokinetic profile of fat-soluble vitamins A, E, K1, and D3 co-administered with liquid paraffin or water in an experimental rat model was investigated. Animals received a solution of the four vitamins orally through a probe, followed 10 minutes later by the administration of either the liquid paraffin product dissolved in water (Emuliquen Simple®) or water (control). Vitamin formulations were 20, 50, 0.30 and 0.10 mg/kg for vitamins A, E, K1, and D3, respectively. Blood samples were collected before dosing and at 0.17, 1, 2, 4, 8, and 24 hours post-dosing. Vitamin concentrations were quantified by liquid chromatography coupled with mass spectrometry. No relevant differences in the absorption of vitamins in terms of AUC0-last (area under the curve up to the last measurable concentration) or Cmax in the absence or presence of co-administration of the liquid paraffin product were observed. The difference of these parameters between the treatment groups for all vitamins was in the range of bioequivalence (≤ 20%). The liquid paraffin-based laxative product did not interfere with the absorption of vitamins A, E, K1, and D3 that are ingested in the diet, which is clinically relevant due to the high prevalence of functional constipation in children and adults.

After the first release of synthalin B (dodecamethylenbiguanide) in 1928 and its later retraction in the 1940s in Germany and the retraction of phenformin (N-Phenethylbiguanide) because of the letal complication of acidosiss,metformin (1-1-dimethylbiguanide) was first released in France in 1959 and then in the USA in 1995 for oral treatment of diabetes type 2. Acute gastrointestinal side effects often lead to dose reduction and strongly limit adherence to therapy.Main long-term consequences are deficency of vitamin B12 and of iron and sometimes also acidosis development. Intravenously injected F18-labelled glucose in metformin-treated type 2 diabetics accumulates in the the small and even more in the large intestine.The densitometry picture observed in metformin-treated diabetics is similar to that observed in patients after bowel-cleansing or chronically taking different types of laxatives where the accumulated radioactivity can even reach values observed in colon cancer. The glucose-lowering mechanism of action of metformin is therefore not only due to inhibition of glucose uptake in the small intestine but also to „attraction“ of glucose from the hepatocyte to the intestine,possibly through its secretion into the bile.Metformin is not different from the other biguanides ,synthalin B and phenformin.The mechanism of action,and the side effects are comparable to those of laxatives.