Rifaximin Amorphous Forms for Stable Bioavailability

The patent applies parameter changes by developing new polymorphic forms of rifaximin with different crystal structures (Forms I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV, XV, XVI, XVII, XVIII, XIX, XX, XXI, XXII, XXIII, XXIV, XXV, XXVI, XXVII, XXVIII, XXIX, XXX, XXXI, XXXII, XXXIII, XXXIV, XXXV, XXXVI, XXXVII, XXXVIII, XXXIX, XL, XLI, XLII, XLIII, XLIV, XLV, XLVI, XLVII, XLVIII, XLIX, L, LI, LII, LIII, LIV, LV, LVI, LVII, LVIII, LIX, LX, LXI, LXII, LXIII, LXIV, LXV, LXVI, LXVII, LXVIII, LXIX, LXX, LXXI, LXXII, LXXIII, LXXIV, LXXV, LXXVI, LXXVII, LXXVIII, LXXIX, LXXX, LXXXI, LXXXII, LXXXIII, LXXXIV, LXXXV, LXXXVI, LXXXVII, LXXXVIII, LXXXIX, XC, XCI, XCII, XCIII, XCIV, XCV, XCVI, XCVII, XCVIII, XCIX, C). Each polymorphic form has distinct physical and chemical properties that affect dissolution rate, bioavailability, and therapeutic consistency while minimizing systemic absorption. The patent specifically identifies X-ray diffraction patterns, melting points, and solubility characteristics for each form to enable selection of the most appropriate polymorph for targeted gastrointestinal treatment.

The patent applies preliminary action by pre-characterizing each polymorphic form's physical and chemical properties including X-ray diffraction patterns, melting points, solubility, and stability profiles before clinical application. This preliminary characterization enables selection of the most suitable polymorphic form for specific therapeutic indications and facilitates development of optimized manufacturing processes. The patent provides detailed descriptions of each form's properties to guide formulation development and production scale-up, reducing the complexity of manufacturing by enabling informed selection of the appropriate polymorphic form upfront.