Crystalline Quinazolinone Ophthalmic Formulations Against Drug Agglomeration

The patent applies parameter changes by identifying and characterizing different polymorphic crystal forms of the hydrophobic TRPV1 antagonist with distinct physical properties. Each crystal form has specific X-ray diffraction patterns, melting points, and solubility characteristics that affect its behavior in aqueous formulations. By selecting appropriate crystal forms and controlling crystallization parameters (temperature, solvent, cooling rate), the formulation stability is improved while maintaining topical administrability.

The patent utilizes phase transitions by describing methods to convert between different crystal forms through controlled heating and cooling cycles. For example, crystal form A can be converted to crystal form B by heating to specific temperatures and then cooling. These phase transition controls prevent unwanted agglomeration and maintain formulation stability during storage and administration.

The patent applies preliminary action by pre-characterizing multiple crystal forms and establishing their conversion conditions before actual formulation manufacturing. The detailed X-ray diffraction patterns, melting points, and solubility data for each crystal form are determined in advance, allowing manufacturers to select the most suitable crystal form for their specific formulation needs without encountering unexpected issues during production.

The patent uses solvent molecules as intermediaries in the crystallization process. Specific solvents (water, ethanol, isopropanol, acetonitrile, DMSO) facilitate the formation of particular crystal forms through solvation and desolvation mechanisms. These intermediary solvent molecules help control the crystallization pathway and can be easily removed or replaced during the formulation process, simplifying manufacturing.