Surfactants

Oral route has been considered as most convenient route but restricted to only hydrophilic compounds having GI stability and greater dissolution. The delivery of lipophilic compounds has been area of interest since most of the drugs under discovery shows limited bioavailability. Self-emulsifying delivery systems (SMEDDS) has drawn a greater attention in the formulation of poorly soluble compounds where increase in the absorption and permeation of the drug has observed. The self-emulsification which occurs in the case of SMEDDS has shown a potential advantage over conventional emulsion due to the fine globules formed upon dilution. The recent trends such as dry emulsion, s-SMEDDS, SNEDDS thoroughly investigated. This article, attempts to present the overview of the SMEDDS along with its formulation, application and characterization.

The discovery of the cubosomes is the unique story & spans the fields of the food science, biological membranes, differential geometry & digestive processes. The cubosomes are the square & rounded particles with the internal cubic lattices visible. The cubosomes are self-assembled nanostructured particles formed by the aqueous lipid & surfactant systems. The cubosomes are the thermodynamically stable, they have the structure like “honeycombed” with the bicontinuous domains of the water & lipid in which the surfactant assembles into the bilayers & twisted into the 3 dimension, periodic & the minimal surface forming the structure which are tightly packed. They exhibit the different internal cubic structure & composition with different drug-loading modalities. In drug nano formulations the cubosome have great potential for the melanoma therapy owing to their potential advantages which includes high drug payloads due to the high internal surface area & cubic crystalline structures relatively biodegradability of lipids, the simple preparation method, targeting & controlled release of the bioactive agents, the ability of encapsulating the hydrophilic, hydrophobic & amphiphilic substances, The cubosome dispersions are biocompatible & bioadhesive. Due to their properties the cubosome are versatile systems administrable by different routes such as parenterally, orally& percutaneously. Hydrating the surfactant or the polar lipid that forms the cubic phase & then dispersing the solid like phase into the smaller particles usually forms the cubosomes. To encapsulate guest molecules such novel particles are utilized which are either amphiphilic, lipophilic or hydrophilic due to its structure compartmentalization.

Various strategies have been widely investigated to enhance the solubility of poorly soluble drugs. These strategies increase the clinical efficacy when the drug is administered orally. Around 40% of novel chemical entities show evidence of poor aqueous solubility and their bioavailability becomes low. Thus to overcome this problem new technologies are applied. This new technologies improve the solubility of those drugs whose water solubility is poor. This new technology is known as SEDDS. Self-emulsifying drug delivery systems (SEDDS), which are isotropic mixtures of oils, surfactants, solvents and co-solvents/surfactants, can be used for the design of formulations in order to improve the oral absorption of highly lipophilic drug compounds. It can be orally administered in soft or hard gelatin capsules. This formulation enhanced bioavailability due to increase the solubility of drug and minimizes the gastric irritation.