The purpose of drug administration through the skin is to treat skin disorders on a topical level or to deliver drugs to the systemic circulation via transdermal absorption due to the variability in peak plasma concentration following oral and parenteral delivery. Ethosomes lipid-based nanovesicles with improved softness, deformability, and elasticity, are the most investigated vesicular system. Ethanol, cholesterol, and lecithin are used to prepare ethosomes. The loose hair follicles and Stratum Corneum (SC) percutaneous route allowed the ethosomes to permeate the epidermis. During percutaneous penetration, the vesicles were released into the superficial layer of the skin, allowing the therapeutic substances to penetrate while the phospholipids remained in the upper epidermis.

Notwithstanding the physiological hurdles in the gastrointestinal tract, enteral delivery is the most practical route of drug administration. Lipid-based formulations known as nanostructured lipid carriers (NLCs) have received much research as drug-delivery nanovesicles. Due to their superior physical stability, biocompatibility, and enhanced drug-loading capacity, NLCs are preferred over other conventional lipidic nano-formulations, such as liposomes, solid lipid nanoparticles (SLNs), and nanoemulsions. NLCs are considered a promising strategy for oral bioavailability (BAV) enhancement of drugs; this could be due to the benefits of nanomaterials as well as the properties of the lipidic composition of the vesicles, which prevent enzyme degradation, mask unpleasant taste, and being favorably taken up to the lymphatic system through chylomicrons. This review particularly emphasizes their applications as oral drug delivery systems; this review discusses the most recent developments in using NLCs as nanocarriers and their composition, preparation, and characterization techniques.

The mucus layer covering the mucosal epithelial surface and mucin molecules interact with the bioadhesive drug delivery method to increase the time the formulations remain at the absorption site. The mucus layer covering the mucosal epithelial surface and mucin molecules interact with the bioadhesive drug delivery method to increase the time the dosage form remains at the absorption site. Bioadhesive formulations may be developed to provide sustained retention at the place of application and to give a controlled rate of medication release for greater therapeutic efficacy. Various factors, including the polymeric formulation's physicochemical properties and the mucosal tissue's content, influence the dosage form's ability to adhere to mucosal surfaces. This review covers the subjects of bio-adhesion mechanisms and theories, bio-adhesion polymers and polymers, various dosage forms and microbead manufacturing techniques.