SMEDDS

Tyrosine kinase inhibitors have shown to be effective in the treatment of chronic myeloid leukemia. These drugs generally belong to the Biopharmaceutical Classification System Class II or IV, indicating that their oral bioavailability is less due to its poor solubility, permeability, or both. Dasatinib is a tyrosine kinase inhibitor and the present study was aimed to overcome these limitations associated with it. Thus, a transdermal system comprising of the drug loaded into a self-microemulsifying drug delivery system was formulated. The study started by selecting the right combination of the oil (oleic acid), surfactant (Labrasol®), and cosurfactant (polyethylene glycol 400) by performing solubility and emulsification ability studies. The ternary phase diagrams were constructed to identify the microemulsion region. The liquid system was converted into an easy-to-handle gel form using 1% w/w Carbopol ETD 2020 as the gelling agent. The final system had a droplet size of 76.42 ± 1.2 nm, a narrow polydispersity index, and a high zeta potential. The thermodynamic stability studies, dispersibility and dilution tests proved that the formulation would be unaffected and would form the microemulsion instantaneously. In vitro dissolution confirmed close to 100% drug release could be obtained within 30 mins as opposed to the plain drug showing only 50 – 60 % release. In vitro permeability studies, revealed a 1.6-times enhancement in the permeation of the drug. Preparation of a self-microemulsifying drug delivery system and loading it into a topical gel could address the issues associated with the effective delivery of dasatinib.

The aim of the present study was to formulate and evaluate self micro emulsifying drug delivery system to enhance the solubility of the BCS class II drug, i.e. itraconazole. SMEDDS of the model drug were prepared using castor oil and benzyl alcohol as oil phase, tween 80 as surfactant and poly ethylene glycol 400 and ethanol as co-solvents. The prepared SMEDDS were characterized by SEM and zeta potential. SMEDDS were evaluated for globule size, stability studies, dispersibility test and in vitro drug release. SEM photograph showed that globules were smooth and spherical in shape. The particle size and zeta potential of prepared formulation was found to be between 8-16 µm and -11.5 to -55.6 respectively. Stability of itraconazole drug was found to depending on the amount of castor oil present in the formulation. As concentration of castor oil in the formulation increases, so the stability. In vitro drug release of the formulations was carried out in pH 1.2 buffer for 2 hours. Formulation F6 showed 98.50% drug release at the end of 2 hours. It was concluded that the SMEDDS prepared seem to promising carriers for enhancing the bioavailability and the solubility of poorly water soluble drug.

The objective of this study was to develop self-emulsifying drug delivery system (SEDDS) to enhance the solubility of the poorly water-soluble drug Orlistat. Orlistat is class II molecule according to BCS (Biopharmaceutical Classification System), having low solubility and low permeability. The rate and extent of absorption of class II compounds is highly dependent on the performance of the formulated product. These drugs can be successfully formulated for oral administration, but care needs to be taken with formulation design to ensure consistent bioavailability. Solubility of Orlistat was evaluated in various nonaqueous carriers that included oils, surfactants, and cosurfactants. Pseudoternary phase diagrams were constructed to identify the self-microemulsification region. Self microemulsifying formulations were prepared using mixtures of oils, surfactants, and cosurfactants in various proportions. The self microemulsification properties, droplet size and thermodynamic stability of these formulations were studied upon dilution with water. The optimized liquid SMEDDS formulation was converted into free flowing powder by adsorbing onto a solid carrier for encapsulation. The dissolution characteristics of solid intermediates of SMEDDS filled into hard gelatin capsules were investigated and compared with pure drug and commercial formulation. The results indicated that solid intermediates showed the rate and extent of drug dissolution for solid intermediates were significantly higher than commercial formulation. The results of the study demonstrated the potential use of SMEDDS as a means of improving solubility, dissolution and concomitantly the bioavailability.

  Self Micro-emulsifying drug delivery systems (SMEDDS) are usually used to improve the bioavailability of hydrophobic drugs. Approximately 60-70% of new chemical entities exhibit poor aqueous solubility and present a major challenge to modern drug delivery system, because of their low bioavailability. SMEDDS is isotropic (one phase system) mixture of oil or modified oils, surfactants and co-surfactants, which form the fine oil-in-water microemulsion when introduced into aqueous phase under condition of gentle agitation. The digestive motility of the stomach and intestine provide the agitation necessary for self-microemulsion in-vivo. Triglyceride is the one of the component of SMEDDS, which helps in the absorption of drugs from the GI tract. SMEDDS enhance the bioavailability enabling reduction in dose of the drug. SMEDDS is evaluated by various methods like visual assessment, droplet polarity and droplet size, size of emulsion droplet, dissolution test, charge of oil droplets, viscosity determination, in-vitro diffusion study. This article gives an overview of improvement in the rate and extent of oral absorption of drugs by SMEDDS approach. The characterization of SMEDDS and application of SMEDDS is also introduced, with particular emphasis being placed on the developments of Solid self micro-emulsifying delivery system and dosage form of SMEDDS.

  The aim of this work was to develop a stable self micro emulsifying drug delivery system (SMEDDS) of herbal extract and evaluating its in vitro potential. The solubility of herbal extract was determined in various vehicles. Pseudoternary phase diagrams were used to evaluate the micro emulsification existence area. Release rate of herbal extract was investigated using a dissolution method. SMEDDS were characterized for clarity, precipitation and particle size distribution. Formulation development and screening was done based on results of solubility & from phase diagram. The optimized formulation used for in vitro dissolution was composed of herbal extract (30 %), Cremophor RH 40 (40 %), Plurol Oleique (30%). The SMEDDS formulation showed complete release in 10 min. as compared with the plain extract and conventional marketed formulation. SMEDDS subjected to various were conditions of storage as per ICH guidelines for 3 months. SMEDDS successfully withstood the stability testing. It has been found that dissolution profile of herbal extract from SMEDDS was much improved. SMEDDS appeared to be an interesting approach to improve solubility, and ultimately bioavailability Key words: SMEDDS; herbal extract; Pseudo-ternary Phase diagram; Self-emulsification