PLGA millicylinders

Figure 4 Polymer water uptake kinetics (A), BSA release from (B) and stability in (C) PLGA millicylinders containing 10% sucrose ( ) or 3% Mg(OH)2 (e). Released BSA, soluble residue, and insoluble residue indicate total BSA release, PBST-soluble, and -insolube BSA recovered from the polymer after 4-week incubation, respectively. BSA loading was 10% (average S.E., n = 3). (From Ref. 42.)...

Therapeutic proteins have also been stabilized in PLGA millicylinders by neutralizing the acidic microenvironment with insoluble basic additives in combination with additional excipients that improve the intrinsic stability of the encapsulated protein. Two examples are provided below using t-PA and basic fibroblast growth factor. 

To stabilize bFGF in PLGA millicylinders, several additives were encapsulated with bFGF in PLGA. Since bFGF is a very potent protein and loaded in the polymer at a very low level (i.e. <0.1%), a water-soluble carrier molecule such as BSA is needed to aid in the transport of the poorly soluble base throughout the polymer for uniform acid neutralization (40). Therefore, Mg(0H)2 and BSA were used to neutralize... 

Figure 12 Controlled-release of bFGF. (A) PLGA millicylinders were loaded with 3% Mg(OH)2/0.0025% bFGF/0.0025%...

Table 9 Stabilization Effect of the Basic Salt on bFGF Delivery from PLGA Millicylinders...

Figure 2 Effect of Mg(OH)2 content on BSA release kinetics (A) and encapsulated BSA aggregation kinetics (B) during incubation of the PLGA implants at 37°C in PBST. Millicylinders were loaded with 15% BSA and 0% ( ), 0.5% (H), and 3.0% (A) Mg(OH)2 (average S.E., n = 3). (From Ref. 8.)...

Table 3 Effect of Mg(OH)2 and BSA Content on BSA Aggregation in BSA/PLGA (0.63 dl/g) Millicylinders after 4-Week Release Study in PBST at 37° C...

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