Formulation and Optimization of Repaglinide Nanoparticles Using Microfluidics for Enhanced Bioavailability and Management of Diabetes

Abstract

The technologies for fabrication of nanocrystals have an immense potential to improve solubility of a variety of the poor water-soluble drugs with subsequent enhanced bioavailability. Repaglinide (Rp) is an antihyperglycemic drug having low bioavailability due to its extensive first-pass metabolism. Microfluidics is a cutting-edge technique that provides a new approach for producing nanoparticles (NPs) with controlled properties for a variety of applications. The current study's goal was to engineer repaglinide smart nanoparticles (Rp-Nc) utilizing microfluidic technology (Dolomite Y shape), and then to perform in-vitro, in-vivo, and toxicity evaluations of them. This method effectively generated nanocrystals with average particle sizes of 71.31 ± 11 nm and a polydispersity index (PDI) of 0.072 ± 12. The fabricated Rp's crystallinity was verified by Differential scanning calorimetry (DSC) and Powder X-ray diffraction (PXRD). In comparison to the raw and commercially available tablets, the fabricated Rp's nanoparticles resulted in a higher saturation solubility and dissolving rate (p < 0.05). Rp nanocrystals had a considerably lower (p < 0.05) IC₅₀ value than that of the raw drug and commercial tablets. Moreover, Rp nanocrystals at the 0.5 and 1 mg/kg demonstrated a significant decrease in blood glucose level (mg/dL, p < 0.001, n = 8) compared to its counterparts. Rp nanocrystals at the 0.5 mg/kg demonstrated a significant decrease (p < 0.001, n = 8) in blood glucose compared to its counterparts at a dose of 1 mg/kg. The selected animal model's histological analyses and the effect of Rp nanocrystals on several internal organs were determined to be equivalent to those of the control animal group. The findings of the present study indicated that nanocrystals of Rp with improved anti-diabetic properties and safety profiles can be successfully produced using controlled microfluidic technology, an innovative drug delivery system (DDS) approach.

Keywords: bioavailability; in-vitro; in-vivo study; microfluidic technology; rats; repaglinide (Rp).

Figure 1

Images of Rp (a) and (b) at different magnification.

Figure 2

Stability study at different storage temperature; (a) at 5 °C (b) at 25 °C and (c) at 40 °C for 30 days.

Figure 3

DSC thermograms of unprocessed (raw) and nanocrystals.

Figure 4

PXRD peaks of unprocessed Rp and Rp-Nc.

Figure 5

Solubility studies of Rp nanocrystals (Rp-Nc) and raw Rp.

Figure 6

In-vitro dissolution studies of the repaglinide.

Figure 7

Effect of Rp-Nc on level of biomarkers. Mean ± SEM (n = 8). Significance was determined statistically using one way ANOVA following Dunnett’s comparison test,^!!! p < 0.001 vs. normal control group and (*** p < 0.001, n = 8) by vs. diabetic control group.

Figure 8

Effect of Rp-Nc on SOD level. Mean ± SEM (n = 8). Significance was determined statistically using one way ANOVA following Dunnett’s comparison test, ^### p < 0.001 vs. normal control group and (*** p< 0.001, n = 8) by vs. diabetic control group.

Figure 9

Photomicrographs of microsection of kidney of rat (A) control group showing the normal histological structure of renal parenchyma and bowman capsule, (B) diabetic group showing focal necrosis of epithelial lining renal tubules with architecture disturbance, (C,D) Rp-Nc 0.5 mg and 1 mg treated groups showing slight hydropic degeneration along restoring histological structure of hepatic lobules, Rp-Nc 1 mg treated group showing slight congestion along restoration of normal histological structure of histological structure of renal parenchyma (H & E scale bar 25 µm).

Figure 10

Photomicrographs of microsection of liver of rat (A) control group showing the normal histological structure of hepatic lobules and normal portal traid, (B) diabetic group showing focal necrosis and apoptosis of hepatocytes associated with mononuclear cell infiltration, (C) Rp-Nc 0.5 mg treated group showing slight hydropic degeneration along restoring histological structure of hepatic lobules, (D) Rp-Nc 1 mg treated group showing restoration of normal histological structure of hepatic lobules and normal portal traid (H & E scale bar 25 µm).

Figure 11

Photomicrographs of microsection of pancreas of rat (A) control group showing the normal histological structure of islets of Langerhans with normal pancreatic acini, (B) diabetic group showing ruptured and destructed islets of Langerhans with damage in beta cells, (C,D) Rp-Nc 0.5 mg and 1 mg treated groups showing some normal islets of Langerhans with some mild destructed in normal pancreatic duct and in between normal pancreatic acini (H & E scale bar 25 µm).