Background

In collaboration with The Woolcock Institute and The University of Sydney, Medlab under a government grant sought to develop NanoCelle® for administration by the nasal route; Insulin (MC-1006) was chosen as the compound most suited.

As an introduction, therapeutic proteins are highly unstable and susceptible to mechanical stress, chemical and enzymatic degradation via oral administration.

To date, protein therapy has been delivered mostly via the subcutaneous route, which can cause unwanted side effects (e.g., skin necrosis, nerve pain, injured capillaries, and topical infection).

Protein administration via a non-invasive intranasal route can circumvent the side effects of injection therapy, improving their acceptability and compliance with treatment.

The objectives were to evaluate the physicochemical properties, cytotoxicity, and effect on cells’ monolayer integrity of an intranasal insulin MC-1006 that is a formulation of insulin in nanosized micelles

Whilst the work was early discovery, the results warrant further investigation.

The Study - published

• Formulation Preparation. Insulin nanomicelle MC-1006 was provided by Medlab Clinical Ltd, Sydney, Australia.

• Physicochemical Characterisation. To determine the particle size, polydispersity index (PDI) and zeta potential of the formulations, containing blank nanomicelle and insulin nanomicelle (pH 2.5 and pH 4.8), using the dynamic light scattering.

• Laser Diffraction Analysis. To evaluate the droplet size of the nasal spray from the 3 formulations.

• In Vitro Cytotoxicity. To assess the toxicity profile of the nanomicelle formulations on RPMI-2650 cells, a nasal septum cell line (5 × 104 cells/well), by a CellTiter 96® AQueous One Solution Cell Proliferation Assay.

• TEER Measurement. To determine the integrity of RPMI-2650 cells’ monolayer prior to its exposure to the formulations and 4h after exposure using an EVOM volt ohmmeter.

• Stability Study. To understand the effect of storage conditions on the size, PDI, and zeta potential of nanomicelle.

The Results

• Blank nanomicelle demonstrated comparable physicochemical properties as insulin nanomicelle prepared at pH 2.5 and pH 4.8 conditions.

• Dv50 values for the insulin nanomicelle (both at pH 2.5 and 4.8) formulations were significantly smaller than for the blank nanomicelle (p < 0.05).

• Insulin nanomicelle at pH 4.8 demonstrated significantly higher cell viability (93.06 ± 1.58%) than insulin nanomicelle at pH 2.5 (86.47 ± 2.35 %) at an equivalent concentration (p < 0.05).

• Blank nanomicelle and insulin nanomicelle at pH 4.8 had no adverse effect on the viability and tight junctions of nasal epithelial cells.

• Insulin nanomicelle at pH 4.8 showed stability when stored at both room temperature and refrigerated conditions (2-5 oC).

The Poster is available here.