Figure 6. Human growth hormone (hGH) stability after encapsulation in a dissolving microneedle patch.

The addition of hGH to Nb2 cell culture in the stationary phase stimulated the proliferation of Nb2 cells, which was recorded at three days after hGH treatment and used as a measure of the functional activity of hGH after encapsulation in dissolving microneedles. Five experimental groups were studied: CMC solution by the reconstitution of a placebo CMC microneedle patch (CMC, negative control, ●), hGH solution (hGH, positive control, ▲), hGH solution mixed with CMC reconstituted from a placebo CMC microneedle patch (hGH + CMC, ▪), hGH and CMC solution reconstituted from a CMC microneedle patch encapsulating hGH (hGH in CMC microneedle patch, ◆), and hGH and CMC solution reconstituted from a CMC microneedle patch encapsulating hGH after storage for three months at ambient conditions (hGH in CMC microneedle patch (three months), ▾). All groups contain CMC and hGH at the same mass ratio (5 hGH: 95 CMC) at all hGH concentrations, except the positive control. Asterisk indicates comparison with the hGH positive control (two-way ANOVA, p > 0.05 for * and p < 0.05 for **). Data points represent the average ± standard deviation for n=4 replicates for all groups.

Source: Ref. [14] (CC BY-NC 3.0).