factors that affect absorption of oral drugs
1 FACTORS AFFECTING DRUG ABSORPTION List of content :-- I. PHARMACEUTICAL FACTORS A] Chemical factors B] Physicochemical properties of drug substances 1.drug solubility & dissolution rate 2.--Which increases the pH of the diffusion layer, which promotes the solubility and dissolution of a weak acid and absorption is bound to be rapid. ï· Reverse in the case of salts of weak bases, it lowers the pH of diffusion layer and the promoted the absorption of basic drugs.
Absorption is a primary focus in drug development and medicinal chemistry, since the drug must be absorbed before any medicinal effects can take place.Moreover, the drug's pharmacokinetic profile can be easily and significantly changed by adjusting factors that affect absorption.or many drugs, reducing the particle size leads to a reduction in the dose that is required to achieve the same therapeutic effect. However, it should be noted that although the reduction of particle size increases the specific surface area and the dissolution rate, it does not affect solubility.
Greater the lipid water solubility coefficient, more is the lipid solubility of the drug and greater is the absorption. Less the coefficient, less is the lipid solubility and less is the absorption. Water film exists on the membranes so part of the drugs must be water soluble to cross this water film.Drugs with benzene ring, hydrocarbon chain, steroid nucleus and halogen groups in their structures are lipid soluble.rea of Absorptive Surface. Area of absorptive surface affects oral as well as other routes. Most of the drugs are given orally because of the large area of absorptive surface, so that greater absorption occurs. Intestinal resection decreases the surface area leading to a decreased absorption.