Research Article

AAPS PharmSciTech

, Volume 10, Issue 1, pp 166-171

First online:

Improving Tenoxicam Solubility and Bioavailability by Cosolvent System

  • Ming-Kung YehAffiliated withDepartment of Pharmacy Practice, Tri-Service General Hospital
  • , Li-Chien ChangAffiliated withSchool of Pharmacy, National Defense Medical Center
  • , Andy Hong-Jey ChiouAffiliated withInstitute of Preventive Medicine, National Defense Medical Center Email author 


The formulation study of tenoxicam, a poorly water-soluble drug, was developed by use of a ternary cosolvent system and has significantly enhanced the solubility. Additionally, the relative bioavailability of testing formulation was also evaluated by New Zealand rabbit with a single i.m. injection. The three-phase diagram for dimethylsulfoxide (DMSO)/propylene glycol/water, DMSO/ethanol/water, and DMSO/polyethoxylated castor oil/ethanol system was developed. The volume ratio of 5:4:1 in the DMSO/polyethoxylated castor oil/ethanol system resulted in a more suitable vehicle than other systems, with a high solubility (20.73 mg/ml) and low viscosity (10.0 Cp). A pharmacokinetic study of bioequivalence (F rel = 0.89) was also obtained. The present study not only provides a novel strategy improving tenoxicam solubility but also helps further scientific knowledge for the development of parenteral formulations.

Key words

bioavailability cosolvent system pharmacokinetics poorly water-soluble drug solubility tenoxicam