Oral bioavailability formulation factors

Most peptides and proteins are currently formulated as parenteral formulations because of their poor oral bioavailability. Nevertheless, oral delivery of peptides and proteins would be the preferred route of administration if bioavailability issues could be overcome, as it offers the advantages of convenient, pain-free administration. Although various factors such as permeability, chemical and metabolic stability and gastrointestinal transit time can affect the rate and extent of absorption of orally administered peptides and proteins, molecular size is generally considered the ultimate obstacle [36]. 

Initial formulations of spironolactone were poorly absorbed from gastrointestinal tract because of less than optimal disintegration and dissolution [72]. In contrast to these early versions, newer preparations display enhanced absorption and oral bioavailability of 90% [73], resulting in a fall by a factor of four in the recommended oral dose of the medications [74]. 

Formulation factors affecting the oral bioavailability from conventional dosage forms such as solutions, suspensions, emulsions, capsules and tablets are described here. 

Name the formulation factors affecting oral bioavailability. 

Formulation factors affecting oral transmucosal bioavailability 175... 

FORMULATION FACTORS AFFECTING ORAL TRANSMUCOSAL BIOAVAILABILITY... 

Fig. 2 Summary of processes involved following the oral administration of a drug in tablet or capsule form. (From Blanchard, J. Gastrointestinal absorption. II. Formulation factors affecting bioavailability. Am. J. Pharm. 1978, 150, 132-151.)...

ABSTRACT. Cyclodextrins are applied to facilitate formulation problems, to improve stability and bioavailability Following factors are determining whether or not cyclodextrins can be applied in oral pharmaceutical preparations ... 

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