Microwave Induced Solid Dispersion as a Novel Technique for Enhancing Dissolution Rate of Repaglinide

Abstract

The aim of the present study was to enhance the solubility, dissolution rate and thus antihyperglycemic activity of a poorly soluble, BCS class II drug repaglinide, using its solid dispersions (SDs) with polyethylene glycol (PEG) 6000. Solid dispersions were prepared by kneading, solvent evaporation, conventional fusion method and microwave induced fusion methods. The dispersions were evaluated for various in vitro parameters such as solubility study, dissolution study, fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). Microwave induced solid dispersions exhibited significant improvement in solubility and dissolution rate compared to that of pure drug. Results of DSC, XRD and SEM study showed translation of crystalline form of RG to amorphous form. Thus, microwave technology offers a simple, efficient, solvent free promising alternative method to prepare solid dispersion of RG with significant enhancement of the in vitro dissolution rate.

Characterization of Novel Solid Dispersions of Moringa oleifera Leaf Powder Using Thermo-Analytical Techniques

“…This proves the success of the solid dispersions. Similar findings were reported by Zawar & Bari [3] for their solid dispersion. Patel et al [37] reported similar results, where the solid dispersions diffraction patterns (semi-crystalline) showed more resemblance to PEG.…”

“…corresponding to its melting point. Similar results were reported by [3]. PEG6000 also showed a single, sharp, and narrow endothermic peak at 63.10 • C with a corresponding enthalpy (∆H) fusion of 193.4 J/g.…”

“…The microwave irradiation method adapted from [3,14] with some modifications was used. Equal amounts (50 g) 1:1 of MOLP and PEG were mixed in a 400 mL glass beaker and subjected to microwave for 2 min at 360 W in a domestic microwave (LG model).…”

“…However, the physical state of the solid dispersion depends on the physicochemical properties of the carrier and ingredient, the ingredient-carrier interactions, and the preparation methods. Hydrophilic polymers, including polyvinylpyrrolidone (PVP), hydroxypropylmethylcellulose (HPMC), and hydroxypropyl cellulose (HPC), polyethylene glycols, as well as sugar alcohols like mannitol and xylitol, are commonly used as solid dispersion carriers [3,4]. Polyethylene glycols (PEGs) with molecular weights of 1500−20,000 are widely used to manufacture solid dispersions.…”

“…The specific benefit of PEGs in the preparation of solid dispersions is that PEGs are miscible/soluble in numerous used organic solvents. The melting points of PEGs are under 65 • C (e.g., the melting ranges of PEG4000 and PEG6000 are 50−60 • C, and 55−63 • C, respectively) [3]. Lower melting points of PEGs are helpful in the manufacturing of solid dispersions by different methods.…”