Novel engineered systems for oral, mucosal and transdermal drug delivery

Abstract

Technological advances in drug discovery have resulted in increasing number of molecules including proteins and peptides as drug candidates. However, how to deliver drugs with satisfactory therapeutic effect, minimal side effects and increased patient compliance is a question posted before researchers, especially for those drugs with poor solubility, large molecular weight or instability. Microfabrication technology, polymer science and bioconjugate chemistry combine to address these problems and generate a number of novel engineered drug delivery systems. Injection routes usually have poor patient compliance due to their invasive nature and potential safety concerns over needle reuse. The alternative non-invasive routes, such as oral, mucosal (pulmonary, nasal, ocular, buccal, rectal, vaginal), and transdermal drug delivery have thus attracted many attentions. Here, we review the applications of the novel engineered systems for oral, mucosal and transdermal drug delivery.

Development and Characterization of Mixed Niosomes for Oral Delivery Using Candesartan Cilexetil as a Model Poorly Water-Soluble Drug

“…In order to overcome the low bile salt stability problems, researchers investigate on the formulation of more stable vesicles. Several attempts including the usage of different lipids (highly fluorinated phospholipids (29)), usage of nonionic surfactants (polysorbate 20 (30)), incorporation of polymers to the bilayer structure (chitosan (27)), and vesicle coating (polysaccharides (31)) have increased the vesicle stability.…”

“…Bile salts are involved in lipid digestion after being synthesized in the liver, and they are released to the gastrointestinal tract. The interaction of bile salts with vesicular systems results in the disintegration of bilayer membrane to mixed micelles and thus leads to the leaking of the active agent (27,28). The steps of this transformation is described as follows: (i) penetration of the bile salts between water and lipid phase and formation of mixed bilayer vesicles with altered permeability, (ii) coexistence of mixed bilayer vesicles with mixed bilayer sheets, (iii) saturation of the bilayers with bile molecules and mixed micelle formation, (iv) disappearance of the bilayer structure.…”

Microneedles for drug delivery: trends and progress

“…Methods that have been employed to solve the short comings of both TDPs and hypodermic injections are ultrasound (Yamashita et al, 1996;Han & Das, 2013;Nayak et al, in press), MNs, iontophoresis (Langkjaer, et al, 1998), electroporation, chemical enhancers and others (Yamashita et al, 1996;Yang et al, 2011). These techniques can overcome the protective SC barrier as they allow the passage of large molecular compounds such as proteins and DNA (Benson & Namjoshi, 2008;Daugimont et al, 2010;Li et al, 2013;Zhang et al, 2014a,b). MN technology, in particular, has grown over the past 15 years and can permit drugs to bypass the SC layer by the insertion of micron sized needles that create micro channels through the SC Mitragotri, 2013;Pierre & Rossetti, 2014).…”

“…intra-venous, intra-muscular, intra-cranial, sub-cutaneous injections, etc. ), inhalation (pulmonary) and TDD (skin appendages) (Sullivan et al, 2008;Li et al, 2013). Oral administration and hypodermic injections are the most common delivery methods with approximately 80% of drugs administered orally.…”

Getting Under the skin: What is the Potential of the Transfollicular Route in Drug delivery?

“…Therefore, a wide range of methodologies have been developed and are being increasingly explored including physical means (e.g., sonophoresis, electroporation, microneedle systems and thermal ablation) as well as chemical means (penetration enhancers or incorporation in carrier systems) [2]. In this context, the hair follicles (HF) play a highly interesting role as penetration shunts of several types of substances, including macromolecules.…”