Liquids & Suspensions

As fewer CDMOs continue to specialize in this area, expertise and experience in liquids has become rarer. On the surface, liquids and suspensions appear deceptively simplistic. Nevertheless, several key challenges frequently present themselves during development:

 Stability Challenges

• Dissolution changes (e.g. bioavailability changes caused by sedimentation or redispersion)

• Viscosity and rheology (e.g. preference for thixotropic liquids for dispensing)

• Polymorphic changes in suspension

• Ostwald ripening (crashing out or change in particle size distribution)

Microbial Stability

In addition, chemically stable liquids may support excessive microbial growth and require specialized excipients to stabilize microbial levels.

 Taste Masking & Flavoring

Taste may also be critical. Very few suitable taste-masking or artificial flavors are non-toxic, so clients are restricted in the types of technologies available for blinded trials or to enhance patient compliance.

 Capabilities:

• Aqueous & non-aqueous solutions

• Powders for reconstitution

• Suspensions (immediate or controlled release)

• Lipid-based liquid formulations

• Self-emulsifying liquids (nano-emulsions)

• Liquids for ophthalmic, topical (including ear drops), or oral delivery

• Liquids for spraying (see inhalation and dosage forms)

• Liquids with ion exchange resins for taste masking

• Pediatric formulations