Dissolution studies of physical mixtures of indomethacin with alpha- and gamma-cyclodextrins

Polymer-embedded deep eutectic solvents (PEDES) as a novel bio-enabling formulation approach

There is a growing interest in using deep eutectic solvents (DES) as a pharmaceutical delivery system for poorly water-soluble compounds. To reduce the risk of drug precipitation following oral administration, this study addresses the hypothesis that directly including a polymeric precipitation inhibitor (PI) in a DES mixture could obtain a polymer-embedded deep eutectic system (PEDES) as a novel bio-enabling formulation principle. Following broad formulation screening, a PEDES embedding 15 % w/w of polyvinyl pyrrolidone K30 (PVP) in L-carnitine:ethylene glycol (1:4, molar ratio) DES was successfully formulated as a supersaturating formulation using indomethacin as model drug. The solubility of 175.6 mg/mL obtained in DES was remarkably high, and upon release (phosphate buffer, pH 6.5) a maximum supersaturation factor of 9.8 was recorded, whereby the release kinetics displayed a suitable "parachute effect". The formulation was further characterized to include a molecular dynamics simulation. It can be concluded that PEDES appears to be a viable novel formulation approach, setting solid grounds for further research to assess the full potential of this novel type of supersaturating drug delivery system.

Stabilization of Metastable Indomethacin α in Cellulose Nanocrystal Aerogel Scaffolds

Indomethacin (IM) is a small molecule active pharmaceutical ingredient (API) that exhibits polymorphism with the γ-form being the most thermodynamically stable form of the drug. The α-form is metastable, but it exhibits higher solubility, making it a more attractive form for drug delivery. As with other metastable polymorphs, α-IM undergoes interconversion to the stable form when subjected to certain stimuli, such as solvent, heat, pH, or exposure to seed crystals of the stable form. In this study, IM was crystallized into cellulose nanocrystal aerogel scaffolds as a mixture of the two polymorphic forms, α-IM and γ-IM. Differential scanning calorimetry (DSC) and Raman spectroscopy were used to quantitatively determine the amount of each form. Our investigation found that the metastable α-IM could be stabilized within the aerogel without phase transformation, even in the presence of external stimuli, including heat and γ-IM seed crystals. Because interconversion is often a concern during production of metastable forms of APIs, this approach has important implications in being able to produce and stabilize metastable drug forms. While IM was used as a model drug in this study, this approach could be expanded to additional drugs and provide access to other metastable API forms.

Inclusion Complexes of Non-Steroidal Anti-Inflammatory Drugs with Cyclodextrins: A Systematic Review

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most widely used classes of medicines in the treatment of inflammation, fever, and pain. However, evidence has demonstrated that these drugs can induce significant toxicity. In the search for innovative strategies to overcome NSAID-related problems, the incorporation of drugs into cyclodextrins (CDs) has demonstrated promising results. This study aims to review the impact of cyclodextrin incorporation on the biopharmaceutical and pharmacological properties of non-steroidal anti-inflammatory drugs. A systematic search for papers published between 2010 and 2020 was carried out using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol and the following search terms: “Complexation”; AND “Cyclodextrin”; AND “non-steroidal anti-inflammatory drug”. A total of 24 different NSAIDs, 12 types of CDs, and 60 distinct inclusion complexes were identified, with meloxicam and β-CD appearing in most studies. The results of the present review suggest that CDs are drug delivery systems capable of improving the pharmacological and biopharmaceutical properties of non-steroidal anti-inflammatory drugs.