*3.6.1 Oral delivery*

Nanoparticle formulations have many benefits over conventional oral delivery methods, including increased absorption, minimized drug toxicity, enhanced oral bioavailability, and excellent clinical potency. Hence, nanoparticle systems have been modified for use in drug delivery systems for compounds such as oral drugs, steroids, hormones, diuretics, and antibiotics [40, 45, 46].

## *3.6.2 Parenteral delivery*

Parenteral delivery via the intravenous route has been used for controlled drug delivery and drug targeting to particular sites. Aliphatic polyester nanoparticles

#### *Aliphatic Polyester Nanoparticles for Drug Delivery Systems DOI: http://dx.doi.org/10.5772/intechopen.100977*

significant in the parenteral delivery system since they can improve drug solubility, long-term stability in the body, biocompatibility, and ease of development for delivery to a targeted site. Nanoparticle formulations have prominent advantages over other systems. Additionally, fine nanoparticles are cleared more slowly than coarse particles [47, 48].
