Semi-solids

Semi-solids are often underestimated and early mistakes in development planning can prove costly. Unlike solid dosage forms, product stability is prone to abruptly worsen late in stability trials incurring substantial losses in investment and development time.

Semi-solid formulations are deceptively complex due to the necessity of incorporating unstable liquids and specialized excipients presenting unique challenges for breaching skin and other membrane barriers.

Core challenges include:

Predictive Model Selection

Trial and error approaches are generally counterproductive leading to incorrect and costly physical/chemical stability and bioavailability (IVIVC) models.

Microbial Stability

Semi-solids often contain water which promotes microbial growth. Common preservatives are often irritants.

Process Development

Process parameters often significantly impact long-term stability in surprising ways. Experience with developing optimized and reproducible manufacture processes is critical.

 Packaging Configuration

Plastic components in packaging or gaskets often migrate into semi-solid products. Compatibility studies are highly recommended (e.g. chemical interaction, leachables & extractables).

Covar’s team has developed a wide variety of semi-solid drugs and is deeply familiar with the chemical, physical, photochemical, and microbial properties of semi-solid formulations, including the wide variety of essential specialty excipients employed. Covar offers full-service development programs including formulation development, ICH stability testing, and clinical supply manufacture and packaging.

 Capabilities:

  • Topical

    • Creams, ointments and gels for local delivery

    • Transdermal delivery systems with modified release for systemic absorption

    • Transdermal delivery systems with absorption enhancers for systemic absorption

  • Ophthalmic

    • Creams, ointments and gels for ophthalmic delivery

  • Vaginal & Rectal

    • Creams, ointments, and gels for vaginal or rectal delivery

Packaging configurations:

  • Tubes & bottles

  • Foil pouches

  • Unit dose pumps, including metered dose devices

  • Vaginal inserts