ORAL BIOAVAILABILITY ENHANCEMENT OF PACLITAXEL USING BIOENHANCER: A REVIEW.

Many new chemical entities with tremendous therapeutic potential are discovered; yet, due to poor solubility and/or membrane penetration characteristics, many of these compounds have undesirable pharmacokinetic qualities. The latter is due to the lipid-like barrier imposed by epithelial mucosal layers, which drug molecules must cross to exert a therapeutic effect. Pre-systemic metabolic breakdown of drug compounds, primarily by cytochrome P450 enzymes found in intestinal enterocytes and liver hepatocytes, is another barrier. Although the nasal, buccal, and pulmonary modes of administration bypass the first-pass effect, systemic drug distribution is still reliant on drug molecules being absorbed via mucosal surfaces. Bio enhancers (naturally derived drug absorption enhancers) have been discovered to increase the amount of unaltered drug in the systemic blood circulation by regulating membrane permeability and/or pre-systemic metabolism. This paper attempts to give an overview of natural bio-enhancers and their key modes of action for medication administration via the nasal, buccal, pulmonary, and oral routes. Injections are frequently used to administer poorly bioavailable drugs, such as large, hydrophilic therapeutics. Bioenhancers may help patients by allowing for systemic distribution of these less bioavailable medications via alternative routes of administration (i.e., oral, nasal, buccal, or pulmonary routes of administration), as well as reducing dosages of tiny molecular pharmaceuticals and so lowering treatment costs. [ABSTRACT FROM AUTHOR]