Morphology Control of Drug Crystallites

The morphology, or shape and size, of finite sized crystallites can have profound effects on the performance of pharmaceutical products. For example, oral delivery typically requires an effective particle size reduction mechanism to improve dissolution behavior, and inhalants require particle sizes in the range of 2-20 μm with uniform aspect ratios. Additionally, particles often need to favorably interact with excipients for formulation purposes.

Since crystallization conditions can profoundly affect the resulting morphologies (needles, platelets), computational predictions of the crystal morphology often prove helpful in understanding and controlling these effects.

Particle Size Control of Drug Crystals

Effective particle size reduction is due to cleavage of the crystallites. Computed surface energies give a direct link to these cleavage energies and can be a valuable guideline to optimize particle size reduction.

Related Case Studies:
Molecular modeling of the crystal cleavage of drugs and pharmaceutical excipients
Morphology & breakage of crystals: Scale-up manufacturing during wet milling of API
Crystal Morphology Tools used in the Fight Against Malaria

Drug Bioavailability, Dissolution, and Interactions with Excipients

Drug bioavailability, dissolution, and interactions with excipients all depend on the interactions occurring at the surfaces of the crystallite. A morphology prediction gives insight into not only the different types of surfaces a crystallite exposes, but also their relative distribution. Simulation tools (such as Amorphous Cell and Forcite) can help in quantifying the interactions between the surfaces of the crystallite and a particular molecule let it be a solvent or an excipient.

Related Software and Services

• Materials Studio Morphology - Predicts crystal morphology from the atomic structure of a crystal
• Materials Studio Amorphous Cell - Provides a versatile technique used to develop an understanding of molecular properties and behavior, especially for liquids and amorphous polymers
• Materials Studio Forcite - Performs energy calculation and geometry optimization of molecules and periodic systems
• Contract Research & Scientific Consulting Services - through access to our full suite of software, the experienced computational scientists at Accelrys can collaborate with you on your projects.