Experimental data of co-crystals of Etravirine and L-tartaric acid

Abstract

Etravirine is a drug used alongside other medication in the treatment of HIV and is a non-nucleoside reverse transcriptase inhibitor. It is a BCS class IV drug, having low solubility and high permeability (Drugbank, https://www.drugbank.ca/drugs/DB06414) [1]. As a result, large doses of the drug are required for treatment. Two pills have to be taken twice a day, making it a "pill burden" (Intelence, http://www.intelence.com/hcp/dosing/administration-options) [2]. Therefore, attempts of co-crystallizing Etravirine are attractive as the solubility of the drug tends to increase in this solid form (Schultheiss and Newman, 2009) [3]. In this study Etravirine co-crystals were synthesized in the molar ratios 1:1, 1:2 and 2:1 with L-tartaric acid as the co-former. Both slow evaporation and physical mixture was performed to mix the components. DSC values of final products are presented as well as FTIR spectra to observe the altered intermolecular interactions. A chemical stability test was performed after seven days using area under curve data from an HPLC instrument.

Keywords: Co-crystals; DSC instrument; Etravirine; FTIR instrument; HPLC.

Fig. 1

Thermograms from DSC analysis of products of Etravirine: L-tartaric acid (A) 1:1 by slow evaporation method, (B) 1:2 by slow evaporation method, (C) 2:1 by slow evaporation and (D) 1:1 by physical mixture.

Fig. 2

FTIR spectra of samples containing Etravirine: L-tartaric acid in molar ratios (A) 1:1 by slow evaporation method, (B) 1:2 by slow evaporation method, (C) 2:1 by slow evaporation* and (D) 1:1 by physical mixture. *Only one of the three batches of molar ratio 2:1 showed a broadened peak around 3500–3300 cm⁻¹.

Fig. 3

Chromatograms obtained from chemical stability analysis. A) 1:1, 0 days, B) 1:1, 7 days C) 1:2, 0 days D) 1:2, 7 days E) 2:1, 0 days F) 2:1, 7 days.