Absorption enhancers oral drug delivery

Fonte, P., Nogueita, T., Gehm, C., Ferreira, D., Sarmento, B., 2011. Chitosan-coated solid lipid nanoparticles enhance the oral absorption of insulin. Drug Delivery and Translational... 

Drug absorption enhancers have been intensively studied over the past three decades [190— 192] in order to increase the oral availability of poorly absorbed drugs (BSC classes II-IV) [193,194]. Much attention has been paid to the synthesis and evaluation of new absorption enhancer molecules. Excluding the preparation of polymer drug conjugates less awareness was focused on the delivery rate of the molecules tested that is, the concomitant input of the poorly soluble drug together with its enhancer, so that maximal area of the small intestine would be exploited for absorption. The differences between the dimensions of the GI tract in... 

Yang, S., et al. 2004. Enhanced oral absorption of paclitaxel in a novel self-microemulsifying drug delivery system with or without concomitant use of P-glycoprotein inhibitors. Pharm Res 21 261. 

Many drugs can now be delivered rectally instead of by parenteral injection (intravenous route) or oral administration. Generally, the rectal delivery route is particularly suitable for pediatric and elderly patients who experience difficulty ingesting medication or who are unconscious. However, rectal bioavailabilities tend to be lower than the corresponding values of oral administration. The nature of the drug formulation has been shown to be an essential determinant of the rectal absorption profiles. The development of novel absorption enhancers with potential efficacy without mucosal irritation (low toxicity) is very important. The delivery of peptide and protein drugs by the rectal route is currently being explored and seems to be feasible. 

Several promising strategies have emerged from the intensive recent research efforts into the oral delivery of peptides and proteins [6, 36, 37]. Absorption enhancers may be used either to temporarily disrupt the intestinal barrier so that drug... 

The in vivo performance of sodium caprate depends on the delivery system and how the drug and sodium caprate are released. The oral bioavailability of a peptide, for instance, was enhanced in rats and dogs using capsules containing a semisolid matrix of sodium caprate, polyethylene glycol and water. In contrast, other formulations were less effective. The extent of absorption enhancement reported ranged from almost no improvement up to fivefold (Aungst et al. 1996 Burcham et al. 1995). 

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