Influence of hydrotrope on solubility and bioavailability of curcumin: its complex formation and solid-state characterization

Solubility-enabling formulations for oral delivery of lipophilic drugs: considering the solubility-permeability interplay for accelerated formulation development

INTRODUCTION

Tackling low water solubility of drug candidates is a major challenge in today's pharmaceutics/biopharmaceutics, especially by means of modern solubility-enabling formulations. However, drug absorption from these formulations oftentimes remains unchanged or even decreases, despite substantial solubility enhancement.

AREAS COVERED

In this article, we overview the simultaneous effects of the formulation on the solubility and the apparent permeability of the drug, and analyze the contribution of this solubility-permeability interplay to the success/failure of the formulation to increase the overall absorption and bioavailability. Three different patterns of interplay were identified: (1) solubility-permeability tradeoff in which every solubility gain comes with a price of concomitant permeability loss; (2) an advantageous interplay pattern in which the permeability remains unchanged alongside the solubility gain; and (3) an optimal interplay pattern in which the formulation increases both the solubility and the permeability. Passive vs. active intestinal permeability considerations in the context of the solubility-permeability interplay are also thoroughly discussed.

EXPERT OPINION

The solubility-permeability interplay pattern of a given formulation has a critical effect on its overall success/failure, and hence, taking into account both parameters in solubility-enabling formulation development is prudent and highly recommended.

Preparation, in vitro and in vivo evaluation of a novel mitiglinide microemulsions

This study aimed to prepare an o/w mitiglinide microemulsion (MTGME) to improve the drug solubility and bioavailability. The formulation of o/w MTGME was optimized by the solubility study of drug, pseudo-ternary phase diagram and Box-Behnken design successively. MTGME was characterized by dynamic laser light scattering (DLS), zeta potential and transmission electron microscopy (TEM), moreover, the storage stability, pharmacodynamics and pharmacokinetics were investigated. The optimal prescription for MTGME consisted of Maisine 35-1 (oil), Cremophor EL (surfactant) and propylene glycol (PG, cosurfactant). MTGME with a spherical dimension of 58.1 ± 5.86 nm was stable when stored at 4 °C for 3 months. The blood glucose levers (BGL) of diabetic mice were uniformly and significantly decreased by intragastric (i.g.) administration of 1-4 mg/kg MTGME, in which BGL (i.g. 4 mg/kg MTGME) was reduced by 69% during 24 h. The pharmacokinetics study of MTGME (i.g., 20 mg/kg) in Wistar rats showed higher plasma drug concentration (Cmax, 2.9 folds), larger area under curve (AUC, 4.6 folds) and oral bioavailability than those of MTG suspensions. Generally, the MTGME (o/w) showed good effect on controlling hyperglycemia. Therefore, microemulsion can be used as an effective oral drug delivery system to improve the bioavailability of MTG.

Improving the Bioavailability and Efficacy of Coenzyme Q10 on Alzheimer's Disease Through the Arginine Based Proniosomes

Coenzyme Q10 (CoQ10) is a fat-soluble vitamin-with a benzoquinone-like structure. CoQ10 plays a role in membrane stability, energy conversion, and ATP production. It is also one of the important antioxidants in the body. The bioavailability of exogenous CoQ10 is extremely low due to its poor aqueous solubility and large molecular mass. In this study, mixed proniosomal drug delivery systems have been used to increase solubility and bioavailability of CoQ10. Arginine (semi-essential amino acid) was incorporated in the formulation composition to achieve higher efficacy by boosting nitric oxide presence, endothelial dysfunction, and cellular uptake. Proniosomes were investigated in terms of particle size, polydispersity index, zeta potential, encapsulation efficiency, and process yield, and optimization studies were carried on by utilizing STATISTICA 8.0 software considering dependent factors (carrier amount, drug amount, and surfactant ratio). Optimum proniosome formulation (particle size 187.5 ± 16.35 nm, zeta potential: -44.7 ± 12.8 mV, encapsulation efficiency 99.05±0.30%, and product yield: 90.55%) was evaluated for thermal analysis, in-vitro drug release using microcentrifuge method. In-vitro cytotoxicity studies of proniosomes were performed on intestinal Epithelial Cells (Cellartis®, ChiPSC18) and no cytotoxic effects was seen during the 72 h. Besides, anti Alzheimer effect was investigated on APPSL-GFP lentivirus-infected human neural cells (APPSL-GFP-l-HNC) and Alzheimer biomarkers (p-tau181 and p-tau217). While CoQ10's relative bioavailability was statistically increased by proniosome compared to CoQ10 suspension (p<0.01, Grubb test). PK parameters of proniosome formulation, obtained with non-compartmental modeling, were fitting to the data (R2=0.956±0.026). The study results proved that proniosomal formulation has a high potential drug delivery system for both increasing bioavailability and anti-Alzheimer effect of CoQ10.