ABSTRACT
The application of biodegradable polymeric particles in the scale of micrometers
and nanometers as a controlled release dosage form of anticancer drugs has
generated immense interest. Due to their relatively large size, however, the
microspheres were not appropriate to direct the drug to target tissues or cells
via systemic circulation or across the mucous membrane [1-3]. Nanoparticles,
instead, were successfully used for systemic, oral, pulmonary, transdermal and
other administration routes for various purposes including drug targeting,
enhancement of drug bio-availability and protection of drug bioactivity and
stability [4-6]. Also, nanoparticles can improve the bioavailability of poorly
absorbed drugs, thus enhancing oral delivery [3, 4]. Moreover, the nanoparticles
are able to permeate cells for cellular internalisation and connective tissue
permeation and so deliver the drug efficiently to the targeted tissue without
clogging capillaries [7, 8]. The ability of nanoparticles to improve drug diffusion
through biological barriers is a typical benefit for the delivery of anticancer
agents. The enhanced endocytic activity and leaky vasculature in the tumor
could result in accumulation of intravenously administered nanoparticles [9].
Some studies have indicated that nanoparticle-bound antitumour agents showed
prolonged drug retention in tumours, reduction in tumour growth and prolonged
survival of tumour-bearing animals [10-13].
