Chapter 11 - Drug nanocrystals as nanocarrier-based drug delivery systems

Abstract

Literature studies over the past few decades have estimated that more than 40% of drug delivery systems have various critical issues such as poor solubility, toxicity, a lack of sensitivity and poor specificity leading to poor and variable bioavailability. This nonspecific distribution of drugs in the body results in potentially strong side effects, which further limits their clinical use. To overcome the limitations of conventional drug administration, there is a great need for controlled drug delivery systems. The designing of site-specific drug delivery systems is challenging. The solution is advanced nanotechnology such as nanocarriers. Nanocarrier-based platforms (i.e., nanoparticles, nanocapsules, nanocrystals, lipid complexes, polymeric micelles, and dendrimers) are systems dedicated to the transport of chemotherapeutically active drugs composed of submicron-sized colloidal nanoparticles with (typically <500nm). Nanocarrier's means sizes of submicron having high surface to volume ratio leading to increased dissolution rate. They have been widely used to deliver poorly soluble drugs to target tissues, organs, or cells. The major aim for their application of drug delivery is to treat an ailment efficiently with the fewest side effects. This results in an enhancement of curative outcomes by exploiting the physiology of the diseased tissue microenvironment. Nanocarriers offer a number of benefits by delivering drugs to tiny areas within the body, reducing drug toxicity. They offers more efficient drug distribution, which makes them an ideal drug delivery module. Nanocarriers are enormously efficient for to transporting drugs over the blood–brain barrier, branching pathways of the pulmonary system, and the tight epithelial junctions of the skin. Because of the leaky constitution of nanocarriers, they have better penetration power in tumors. Drug nanocrystals and nanosuspensions have been recognized as efficient and successful approaches to drug delivery. These nanocrystals are composed of unadulterated drug crystals (sizes within the nanometer range). Only a thin coating of surfactants needs to be added for steric and electrostatic surface stabilization. In this chapter, we will discuss various properties, synthetic routes for production, and the applications of nanocrystals in drug delivery systems.