Besides the considerable differences in the intestinal absorption of the 
different antibiotic classes as described in part I of this paper galenic 
preparations and the administration in form of a capsule -- tablet or sirup play 
a major role too. The particle size of antimicrobial drugs in sirup form has to 
be carefully selected. It should not be too small to prevent a rapid decay of 
the substance by gastric acid; if it is too large the dissolution of the 
substance is not fast enough for maximal absorption in the upper intestinal 
tract. Enteric coating, soluble binders, the dissolution time of a tablet are 
other important variables in the absorption of orally administered antibiotics. 
The most important influence on the resorption of orally administered 
antibiotics comes from the patient. Individual variations in the absorption are 
exceptionally high with amoxycillin. Different age groups show considerable 
variations in intestinal absorption which can amount to an extent of a two to 
threefold increase or decrease over the mean. Simultaneous administration of 
food or drugs have significant influences on the absorption of certain 
antibiotics. The pharmacokinetic investigation and bioavailability studies are 
done on healthy young adults. Diseases of the intestinal tract like acute 
diarrhea or malabsorption syndromes influence the absorption of orally 
administered antibiotics to a considerable extent which even renders some drugs 
completely ineffective. In cystic fibrosis the enteral absorption is retarded 
and pharmakokinetic parameters sizably altered.