DESIGN AND EVALUATION OF ETRAVIRINE SUSTAINED RELEASE TABLETS PREPARED BY LIQUISOLID COMPACT TECHNIQUE USING POLYMERS

Abstract

Background
Etravirine is a second-generation non-nucleoside reverse transcriptase inhibitor (NNRTI) used in the treatment of HIV-1 infection. Owing to its poor aqueous solubility and dissolution rate-limited absorption, development of a sustained release dosage form remains challenging. Liquisolid compact technology offers a promising approach to improve dissolution while simultaneously controlling drug release.
Objective
The present study aimed to formulate and evaluate sustained release (SR) tablets of Etravirine using the liquisolid compact technique with natural polymers such as guar gum and xanthan gum. Propylene glycol and Tween 80 were employed as non-volatile liquid vehicles.
Methods
Twelve formulations (F1–F12) were prepared using varying concentrations of guar gum and xanthan gum in combination with propylene glycol or Tween 80. Pre-compression parameters including bulk density, tapped density, Carr’s index, Hausner ratio, and angle of repose were evaluated. The compressed tablets were characterized for weight variation, hardness, thickness, friability, drug content, and in vitro dissolution. Drug release kinetics were analyzed using Zero-order, First-order, Higuchi, and Korsmeyer–Peppas models. Drug–excipient compatibility was assessed by FTIR spectroscopy.
Results
All formulations exhibited satisfactory flow characteristics and compressibility. Post-compression evaluation demonstrated acceptable hardness (4.39–5.98 kg/cm²), friability (<1%), and drug content (98–102%). Dissolution studies revealed prolonged drug release up to 12 h. Among all formulations, F2 exhibited the most desirable sustained release profile with 100% drug release at 12 h. Kinetic analysis indicated that drug release followed first-order kinetics (R² = 0.984) and showed the highest correlation with the Higuchi diffusion model (R² = 0.980), suggesting diffusion-controlled release. The diffusion exponent (n = 0.814) indicated anomalous (non-Fickian) transport. FTIR studies confirmed the absence of drug–excipient interactions.
Conclusion
The study demonstrated that Etravirine sustained release tablets can be successfully developed using the liquisolid compact technique. The formulation containing xanthan gum with propylene glycol (F2) exhibited optimal sustained release behavior and may serve as a promising oral controlled-release system for improving patient compliance and therapeutic efficacy.