Ever since Dr Charles Pravaz (1790-1853), a French surgeon, invented the hypodermic syringe, injectable solutions have been a key instrument in delivering therapeutic agents providing the advantages of parenteral administration such as rapid onset of action, avoidance of chemical and enzymatic degradation as well as overcoming the absorption barrier in the intestinal tracts.
Delivery of a solid formulation via the parenteral route represents a seismic shift in development pharmaceutics. Glide Pharma combines these advantages with the convenience and stability of solid formulations.
Solid injectable formulations offer many potential advantages:-
- Stability
- Controlled release profile
- Solubility improvement for poorly soluble drugs
- Enhanced immunogenicity for vaccines
- Bioequivalence to liquid injectables
All excipients used in Glide formulations either have a history of use in approved parenteral products or have GRAS status.
Stability
Solid dosage forms confer significantly reduced molecular mobility in comparison with liquid formulations, which explains why most solid dosage forms (e.g. tablets) are room temperature stable whereas the liquid forms (e.g. injectables) often require cold chain storage.
In addition, proprietary stabilisation formulations are being developed at Glide Pharma to provide further protection to thermally labile biological macromolecules or small molecular weight APIs.
Controlled release
There has been some rapid progress in the development of controlled or sustained delivery of injectable drugs. Hydrogels, microspheres and implant formulations have been developed to achieve a range of release profiles. However, the delivery of these dosage forms often requires large diameter needles, which can lead to significant issues with patient compliance or increased costs as healthcare professionals are required to carry out the administration.
These problems are elegantly overcome using the Glide SDI®.
Insoluble compounds
Formulations of water insoluble compounds often involve the use of organic co-solvents and surfactants, which can cause drug precipitation, pain, inflammation and haemolysis on injection. Glide solid injectable formulations can substantially improve the dissolution of the insolubles by entrapping them within glass matrices, encapsulating them within cyclodextrin or formulating as solid emulsions.
Bioequivalence to liquid injectables
Bioequivalence of Glide solid injectable formulations has been demonstrated in a range of animal models as well as an abbreviated Phase 1 clinical study compared to a subcutaneous injection with a needle and syringe.
Enhanced immunogenicity for vaccines
Protective immunity was obtained with just a single subcutaneous administration of a Glide flu antigen formulation whereas two doses were required for the needle and syringe injection of the same re-constituted formulation. There is a possibility that the solid injection may have enhanced the activities of the antigen presenting cells though the Glide route of administration.
Enhanced immunogenicity was also observed with other antigens.
