Design and Development of Herbosomes: A Nove Strategy to Overcome the Bioavailability Hurdle of Quercetin

ABSTRACT

Alike many allopathic lipophilic drug molecules, these natural phyto-constituents are potent, lipophilic, but pose problems like poor aqueous solubility, slower drug release profile, and, reduced bioavailability leading to inferior therapeutic efficacy. This creates scope as well as a challenge for researchers to overcome the above-mentioned problems while developing a formulation for poorly aqueous soluble phytoconstituents. Herbosome is one of the efficient techniques to improve these problems. Herbosome /Phytosome is nothing but the combination of liposome with phytoconstituents forming H-bond anchored amphiphilic drug-phospholipids complexes. Quercetin i.e. 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4H-1-benzopyran-4-one is a polyphenolic flavonoid with potent and diverse biological effects like anti-inflammatory, anti-proliferative, and anti-mutagenic. However, like many other potent drugs, its usage is limited due to its poor aqueous solubility. To overcome this problem, an ameliorated complex of phospholipids loaded with quercetin was developed to improve its aqueous solubility for better absorption. Thus quercetin encapsulated in herbosomes/phytosomes was assessed for the phospholipid complex formation, appearance, surface, and porosity evaluation using different physicochemical tests like FT­IR, DSC, XRPD, 1H-NMR, SEM, and solubility studies. Apart from this anti-oxidant activity of quercetin was evaluated in vitro. The surface characteristics of herbosomes appeared to be flocculent and permeable with a coarse surface in SEM studies whereas FTIR, DSC, 1H-NMR, and XRPD data, confirmed the formation of the phospholipids complex. There were 12 folds improvement in aqueous solubility of per se quercetin and quercetin encapsulated in herbosome (i.e. from 3.44 µg/ml to 36.81 µg/ ml). On the other hand, the results of in vitro anti­oxidant activity of phytosomic quercetin showed no significant statistical difference compared to per se quercetin thus indicating no adverse effects of complexation on quercetin’s availability for anti­oxidant activity. Further, we prepared tard-gelatin capsules containing phytosomic quercetin and evaluated them for drug release, drug content, and solubility studies like dissolution, disintegration, drug content, and stability studies. The results for the evaluation of the kinetics of drug release were in line with the Korsmeyer Peppas model. The drug stability studies did not affect the drug's organoleptic properties, disintegration time, drug content, and in-vitro drug release of the formulation.

Keywords:  Quercetin, Aqueous solubility, Herbosome, Drug release, and in vitro study.