Spanlastics gel-A novel drug carrier for transdermal delivery of glimepiride.

Glimepiride (3rd-generation sulfonylurea) is used for treatment of type 2 diabetes, but its oral administration has been associated with severe gastric disturbances such as nausea, vomiting, heartburn, anorexia, haemolytic anaemia. Accordingly, the transdermal route may represent a potentially suitable alternative. This work investigates the usefulness of a novel drug carrier system for transdermal application. The system investigated were called spanlastics gels and constituted span 60 with edge activator (tween 60 or tween 80). Spanlastics gel has been introduced as a stable form alternative to the liquid formulations of spanlastics. Spanlastics gels were prepared by coacervation phase separation method. Entrapment efficiency and size of spanlastics vesicles produced from the hydration of spanlastics gels were characterised. In vitro release and skin permeation of glimepiride from various spanlastics gel formulations were investigated across mixed cellulose membrane and excised rabbit skin. The obtained results indicated that the maximum entrapment efficiency was 65.36% when the tween 60 content was 30%. The drug release and permeation were increase as the concentration of edge activator increased. Spanlastics gel prepared with Tween 80 at concentration 50% showed higher permeability and flux value (248.69 µg/cm2and 8.31 µg/cm2.h, respectively) through rabbit skin.

Enhancing the Oral Bioavailability of Candesartan Cilexetil Loaded Nanostructured Lipid Carriers: In Vitro Characterization and Absorption in Rats after Oral Administration.

Candesartan Cilexetil (CC) is a prodrug widely used in the treatment of hypertension and heart failure, but it has some limitations, such as very poor aqueous solubility, high affinity to P-glycoprotein efflux mechanism, and hepatic first-pass metabolism. Therefore, it has very low oral bioavailability. In this study, glyceryl monostearate (GMS) and Capryol™ 90 were selected as solid and liquid lipids, respectively, to develop CC-NLC (nanostructured lipid carrier). CC was successfully encapsulated into NLP (CC-NLC) to enhance its oral bioavailability. CC-NLC was formulated using a hot homogenization-ultrasonication technique, and the physicochemical properties were characterized. The developed CC-NLC formulation was showed in nanometric size (121.6 ± 6.2 nm) with high encapsulation efficiency (96.23 ± 3.14%). Furthermore, it appeared almost spherical in morphology under a transmission electron microscope. The surgical experiment of the designed CC-NLC for absorption from the gastrointestinal tract revealed that CC-NLC absorption in the stomach was only 15.26% of that in the intestine. Otherwise, cellular uptake study exhibit that CC-NLCs should be internalized through the enterocytes after that transported through the systemic circulation. The pharmacokinetic results indicated that the oral bioavailability of CC was remarkably improved above 2-fold after encapsulation into nanostructured lipid carriers. These results ensured that nanostructured lipid carriers have a highly beneficial effect on improving the oral bioavailability of poorly water-soluble drugs, such as CC.

Application of Optimization Technique to Develop Nano-Based Carrier of Nigella Sativa Essential Oil: Characterization and Assessment.

BACKGROUND: Chitosan, a naturally occurring polymer, has interesting applications in the field of drug delivery due to its plentiful advantages as biodegradability, biocompatibility and nontoxic nature. Nigella sativa essential oil is unstable, volatile, and insoluble in water and these problems confine its usage in developing new medicines. OBJECTIVE: This study focuses on developing a chitosan-based nanocarrier for the encapsulation of Nigella Sativa essential oil. By using Quality by design outline, the quality target product outline, critical quality attributes and critical material attributes were defined by knowledge and risk-based procedures. METHODS: According to defined critical material attributes, Optimization software (Statgraphics XVII) was used to study the effect of the processing parameters. The processing parameters identified and fixed first with a "One factor at a time" approach. Various physicochemical characterization techniques were performed. RESULTS: As a result, the ratio of chitosan to benzoic acid (2:1) along with the stirring rate (4000 rpm) produced minimum-sized particles (341 nm) with good stability. The anti-bacterial activity study using Staph. Aureus strain proved that the optimized nanoparticles were more efficacious than the pure oil based on the diameter of inhibition zone obtained (diameter =5.5 cm for optimized formula vs diameter = 3.6 cm for pure oil). Furthermore, MTT (methyl thiazolyl-diphenyl-tetrazolium bromide) assay was performed to compare the in vitro cytotoxicity using two different cell lines (i.e. HCT 116 for colorectal carcinoma and PC3 for prostatic cancer). It was found that in both cell lines, the optimized nanoparticles had noteworthy antiproliferative properties illustrated by determining the concentration at which 50% of growth is inhibited (IC50). The optimized nanoparticles showed lower IC50 (17.95 ±0.82 and 4.02 ±0.12µg/ml) than the bare oil IC50 (43.56 ±1.95 and 29.72 ±1.41µg/ml).