Nevirapine
(NEV) is an antiretroviral drug which falls under the
Biopharmaceutics Classification System (BCS) class II category. In
this work, we report the synthesis of new eutectic and cocrystal of
NEV with enhanced dissolution. NEV resulted into an eutectic with
paracetamol (PAR) at a NEV mole fraction (XNEV) of 0.25
(corresponding to a NEV-PAR stoichiometric ratio of 1:3). Evaporative
crystallization using ultrasound and a slurry conversion of NEV with
trimesic acid (TMA) in methanol yielded a methanol solvate of NEV-TMA
(1:1) cocrystal. Also, a new NEV-trimellitic acid methyl ester (TMEA
methyl ester) (1:1) cocrystal hydrate was obtained during ultrasound
assisted evaporative cocrystallization of NEV-trimellitic acid anhydride
(TMEA)-XNEV-0.5 owing to transformation (esterification)
of the coformer, TMEA to TMEA methyl ester in methanol. The single
crystals of these cocrystals were characterized by single crystal
X-ray diffraction (SCXRD) analysis. The eutectic and cocrystals were
also characterized by powder X-ray diffraction (PXRD) analysis, field
emission-scanning electron microscopy (FE-SEM) analysis, thermal analysis,
and vibrational spectroscopic analysis. Powder dissolution studies
conducted in deionized water containing 0.1 wt % of sodium dodecyl
sulfate (SDS) at 37 °C showed that NEV-PAR-SSG-XNEV-0.25 eutectic exhibited 3.07 times enhanced dissolution than raw
NEV, whereas NEV-TMA (1:1) cocrystal methanol solvate prepared by
evaporative crystallization and slurry conversion exhibited 2.51 times
and 2.42 times enhanced dissolution than raw NEV.