Meloxicam-amino acids salts/ion pair complexes with advanced solubility, dissolution, and gastric safety

Abstract

Amino acids have attracted attention as a potential functional excipient for optimizing biopharmaceutics characteristics of poorly soluble drugs. The amino acids are a diverse class with many functional groups, natural compounds, biocompatible and low molecular weight substances. Two amino acids serine and arginine were investigated with meloxicam. Meloxicam has extremely low solubility; being NSAIDs, gastric upset and ulcer are common side effects. Solid dispersions were produced by precipitation and physical mixing techniques. The produced combinations underwent in vitro dissolution, docking, DSC, FTIR, XRD, solubility and gastric ulcer formation studies. Docking indicated formation of ion pair/salt between the basic amino acid arginine and meloxicam. Both solubility and dissolution rates were increased by up to 3000- and 12-fold, respectively. DSC, FTIR an XRD supported these findings. Rats treated with meloxicam showed loss of surface gastric epithelium integrity and ulceration. The animal group received meloxicam: arginine showed intact gastric mucosa with the surface epithelium and gastric glands well organized and nearly similar to the untreated control. Arginine with the guanidine group that was capable of preserving gastric mucosa after repeated administration for 10 days. This study highlighted the role of arginine as a functional excipient that did not only improve solubility and dissolution rates but ameliorated the long-standing gastric side effects attributed to meloxicam.