Synthesis, Characterization, Biodegradation, and Drug Delivery Application of Biodegradable Lactic/Glycolic Acid Polymers: Part III. Drug Delivery Application

Figures & data

Figure 1. A schematic illustration of the solvent extraction method used for preparation of the progesterone-containing PLGA microspheres.

Figure 2. A micrograph of the progesterone-containing PLGA microspheres.

Table 1. Effect of polymer composition on size of the progesterone-containing PLGA microspheres

Molar ratio of lactic to glycolic acid moiety	Number-weighted average size (µm)	Volume-weighted average size (µm)
50:50	13.61	59.47
65:35	13.47	65.05
75:25	11.05	68.49
85:15	9.53	69.21
100:0	7.40	64.53

Molecular weight of the PLGA: 11,351–14,914.

Theoretical/feeding drug content: 10% by weight.

Table 2. Effect of polymer molecular weight on size of the progesterone-containing PLGA microspheres

Molecular weight (Dalton)	Number-weighted average size (µm)	Volume-weighted average size (µm)
12,459	12.33	70.02
32,216	4.15	53.30
61,524	11.79	76.31
81,965	9.14	118.49
116,470	9.00	134.72

Polymer composition: molar ratio of lactic to glycolic acid moiety = 75:25.

Theoretical/feeding drug content: 10% by weight.

Figure 3. Volume-weighted size distribution of the progesterone-containing PLGA microspheres.

Table 3. Effect of polymer composition on drug encapsulation efficiency of the progesterone-containing PLGA microspheres

Molar ratio of lactic to glycolic acid moiety	Actual drug content (%)	Drug encapsulation efficiency (%)
50:50	8.64	86.37±7.11
65:35	8.27	82.67±4.04
75:25	7.32	73.21±12.06
85:15	9.57	95.70±8.77
100:0	8.26	82.63±3.97

Molecular weight of the PLGA: 11,351–14,914.

Theoretical/feeding drug content: 10% by weight.

Table 4. Effect of polymer molecular weight on drug encapsulation efficiency of the progesterone-containing PLGA microspheres

Molecular weight (Dalton)	Actual drug content (%)	Drug encapsulation efficiency (%)
12,459	8.10	80.97±10.62
32,216	9.00	89.98±8.62
61,524	9.46	94.55±13.40
81,965	9.77	97.65±1.05
116,470	10.19	101.87±8.02

Polymer composition: molar ratio of lactic to glycolic acid moiety = 75:25.

Theoretical/feeding drug content: 10% by weight.

Figure 4. Effect of polymer composition (molar ratio of lactic to glycolic acid moiety) on progesterone release from the PLGA microspheres. (Molecular weight of the PLGA: 11,351–14,914 Dalton; Theoretical/feeding drug content: 10% by weight).

Figure 5. Effect of polymer molecular weight on progesterone release from the PLGA microspheres. (Polymer composition: molar ratio of lactic to glycolic acid moiety = 75:25; Theoretical/feeding drug content: 10% by weight).

Figure 6. Effect of drug content on progesterone release from the PLGA microspheres. (Polymer composition: molar ratio of lactic to glycolic acid moiety = 75:25; Molecular weight of the PLGA: 14,914 Dalton).