Crystal engineering approach was utilized for the development of different multicomponent solid forms of telmisartan (TEL) to improve its oral bioavailability. In this context, two cocrystals, gentisic acid (GA) and maleic acid (MA), while two eutectic mixtures, para-aminobenzoic acid (PABA) and adipic acid (AA), were successfully prepared and characterized by different analytical tools. Both the cocrystals exhibited characteristic heterosynthons, viz. OHacid⋯Narom and OHacid⋯O, to propagate new network. Structural features of coformers has been correlated with the outcomes of cocrystallization approach. Coformers having auxiliary functionality in addition to complementary functional groups have high propensity to generate cocrystals. However, multicomponent where auxiliary functionality is lacking, such combinations, is shown to form eutectic mixtures owing to strong homomeric interaction. Besides, the developed cocrystals and eutectic mixtures showed higher aqueous solubility (3-5.5-fold) and intrinsic dissolution rate (1-2.6-fold) over pure TEL. In vivo studies also revealed significant improvement in relative bioavailability (2-2.6-fold). The study also shed light on the implications of eutectic mixtures in mitigating the solubility issues of drugs which are often considered negative results of cocrystallization strategy.
Keywords: bioavailability; cocrystals; crystal engineering; eutectic mixtures; multicomponent solid forms.