Probucol-Ursodeoxycholic Acid Otic Formulations: Stability and In Vitro Assessments for Hearing Loss Treatment

J Pharm Sci. 2024 Aug;113(8):2595-2604. doi: 10.1016/j.xphs.2024.04.032. Epub 2024 May 10.

Abstract

Targeted drug delivery is an ongoing aspect of scientific research that is expanding through the design of micro- and nanoparticles. In this paper, we focus on spray dried microparticles as carriers for a repurposed lipophilic antioxidant (probucol). We characterise the microparticles and quantify probucol prior to assessing cytotoxicity on both control and cisplatin treated hair cells (known as House Ear Institute-Organ of Corti 1; HEI-OC1). The addition of water-soluble polymers to 2% β-cyclodextrin resulted in a stable probucol formulation. Ursodeoxycholic acid (UDCA) used as formulation excipient increases probucol miscibility and microparticle drug content. Formulation characterisations reveals spray drying results in spherical UDCA-drug microparticles with a mean size distribution of ∼5-12 μm. Probucol microparticles show stable short-term storage conditions accounting for only ∼10% loss over seven days. By mimicking cell culture conditions, both UDCA-probucol (67%) and probucol only (82%) microparticles show drug release in the initial two hours. Furthermore, probucol formulations with or without UDCA preserve cell viability and reduce cisplatin-induced oxidative stress. Mitochondrial bioenergetics results in lower basal respiration and non-mitochondrial respiration, with higher maximal respiration, spare capacity, ATP production and proton leak within cisplatin challenged UDCA-probucol groups. Overall, we present a facile method for incorporating lipophilic antioxidant carriers in polymer-based particles that are tolerated by HEI-OC1 cells and show stable drug release, sufficient in reducing cisplatin-induced reactive oxygen species accumulation.

Keywords: Cisplatin; Cyclodextrin; Drug delivery; HEI-OC1; Hearing loss; Probucol; UDCA.

MeSH terms

  • Animals
  • Antioxidants* / administration & dosage
  • Antioxidants* / chemistry
  • Antioxidants* / pharmacology
  • Cell Line
  • Cell Survival / drug effects
  • Cisplatin / administration & dosage
  • Cisplatin / pharmacology
  • Drug Carriers / chemistry
  • Drug Compounding / methods
  • Drug Liberation
  • Drug Stability*
  • Excipients / chemistry
  • Hair Cells, Auditory / drug effects
  • Hair Cells, Auditory / metabolism
  • Hearing Loss / chemically induced
  • Hearing Loss / drug therapy
  • Mice
  • Particle Size
  • Probucol* / administration & dosage
  • Probucol* / chemistry
  • Probucol* / pharmacokinetics
  • Probucol* / pharmacology
  • Ursodeoxycholic Acid* / administration & dosage
  • Ursodeoxycholic Acid* / chemistry
  • Ursodeoxycholic Acid* / pharmacology

Substances

  • Probucol
  • Ursodeoxycholic Acid
  • Antioxidants
  • Cisplatin
  • Drug Carriers
  • Excipients