Journal
ANNALS OF BIOMEDICAL ENGINEERING
Volume 51, Issue 5, Pages 966-976Publisher
SPRINGER
DOI: 10.1007/s10439-022-03109-6
Keywords
Controlled release; Long-acting injectable; Protein release; Stabilization; Additives; Acidic microclimate
Categories
Ask authors/readers for more resources
There is a need to reduce the frequency of injections for protein drugs, and in situ forming implants (ISFIs) have shown potential for controlled release. However, protein instability is a challenge due to the acidic microclimate within ISFIs. This study demonstrates that adding basic salts can neutralize the acidic environment, improving protein stability and the potential of ISFIs for delivering pH-sensitive biomolecules.
There is a growing number of protein drugs, yet their limited oral bioavailability requires that patients receive frequent, high dose injections. In situ forming implants (ISFIs) for controlled release of biotherapeutics have the potential to greatly reduce the injection frequency and improve patient compliance. However, protein release from ISFIs is a challenge due to their proclivity for instability. Specifically, factors such as the acidic microclimate within ISFIs can lead to protein aggregation and denaturation. Basic salts have been shown in PLGA microparticle and microcylinder formulations to significantly reduce protein instability by neutralizing this acidic environment. The overall objective of the study was to demonstrate that basic salts can be used with an ISFI system to neutralize the implant acidification. To this end, the basic salts MgCO3 and Mg(OH)2 were added to a protein-releasing ISFI and the effect on drug release, pH, implant swelling, implant diffusivity, and implant erosion were evaluated. Either salt added at 3 wt% neutralized the acidic environment surrounding the implants, keeping the pH at 6.64 +/- 0.03 (MgCO3) and 6.46 +/- 0.11 (Mg(OH)(2)) after 28 day compared to 3.72 +/- 0.05 with no salts added. The salts initially increased solution uptake into the implants but delayed implant degradation and erosion. The 3 wt% Mg(OH)(2) formulation also showed slightly improved drug release with a lower burst and increased slope. We showed that salt additives can be an effective way to modulate the pH in the ISFI environment, which can improve protein stability and ultimately improve the capacity of ISFIs for delivering pH-sensitive biomolecules. Such a platform represents a low-cost method of improving overall patient compliance and reducing the overall healthcare burden.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available