Chitosan glutamate hydrogels with local anesthetic activity for buccal application

Figures & data

Table 1.  Composition of CHG-LDC hydrogels.

Batch	% CHG	% LDC	% Glycerine	Water (ml)
A1	2.5	5	10	30
A2	2.5	5	5	30
B1	5	5	10	30
B2	5	5	5	30
B3	5	5	0	30
B4	5	5	25	30
C2	4	5	5	30
D1	1	5	10	30

Table 2.  Viscosity (mPas.s) of LDC-loaded CHG hydrogels stored at room temperature (23 ± 2°C) or in a refrigerator (4 ± 1°C) up to 12 months.

Batch	Room temperature				4 ± 1°C
	t = 0	t = 3 m	t = 7 m	t = 12 m	t = 12 m
B1	173,000	126,000	125,000	114,000	198,000
B2	123,000	144,000	132,700	133,000	192,000
B3	88,000	94,600	—	125,000	127,000
B4	100,100	97,800	113,000	121,500	114,000
A1	75,000	96,700	—	135,000	124,000
A2	74,000	66,000	—	58,000	85,000
C2	70,000	66,000	—	55,000	78,000
D1	73,000	52,000	59,700	93,500	123,200

Figure 1.  LDC release profile from hydrogels prepared with different amounts of CHG (glycerin: 5% by weight) (n = 4).

Figure 2.  LDC release profile from hydrogels prepared with different amounts of CHG (glycerin: 10% by weight) (n = 3).

Figure 3.  LDC release profile from hydrogels prepared with a fixed percentage of CHG (5% by weight) and different glycerin amounts (n = 3 or 4).

Figure 4.  Comparison among LDC in vitro release profiles from two CHG hydrogels and the two reference commercial products (n = 3 or 4).

Figure 5.  Changes in the in vitro LDC release profiles from hydrogel B1 (5% CHG, 10% glycerin) at different storage times at 4 ± 1°C (n = 3).

Table 3.  Duration of the local anesthetic activity (minutes) in vivo. Numbers 1–7 refer to the evaluators. Analysis of Variance was applied between Xylocaina^® gel and each hydrogel, while the Student’s t-test was used to compare the various hydrogels.

Hydrogel	1	2	3	4	5	6	7	Mean	± SD
B1	28	25	21	27	23			24.8	2.86
B3	27		24	28	27			26.5	1.73
B4	10	15				15	11	12.5	2.63
D1		18	22	16			20	18.7	2.58
A2	24	19		30	26	25		24.7	3.96
Xylocaina^®	25	20	15		15			18.7	4.79