A Novel Approach for Development and Characterization of Effective Mosquito Repellent Cream Formulation Containing Citronella Oil

Table 5

Erythema and edema scores for skin irritation index.

Sample	Reactions	4 h						24 h						48 h						72 h						PII	Results
		1	2	3	4	5	6	1	2	3	4	5	6	1	2	3	4	5	6	1	2	3	4	5	6
Saline
—	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0.0	Nonirritant
	Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Base
Test site	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	1	0	0.0416^ns	Irritation barely perceptible
	Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Control site	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1
	Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Standard irritant
Test site	Erythema	2	2	3	2	2	2	2	2	2	2	2	3	2	2	2	1	2	1	1	1	1	2	1	1	3.833***	Moderately irritant
	Edema	4	4	4	4	4	3	4	4	3	2	2	3	3	2	1	2	1	1	1	1	2	2	1	1
Control site	Erythema	0	1	0	1	0	1	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0
	Edema	0	1	0	1	0	1	0	0	0	1	0	0	1	0	0	0	0	0	0	0	0	0	0	0
CEO
Test site	Erythema	1	1	1	1	1	1	1	1	1	2	2	2	2	2	3	3	3	3	3	3	3	3	3	4	2.035^***a	Mildly irritant
	Edema	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Control site	Erythema	1	0	0	0	0	0	0	0	1	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0
	Edema	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
B5
Test site	Erythema	0	0	2	1	1	1	1	1	1	1	0	2	0	1	0	1	0	1	0	0	0	0	0	0	0.45^ns/a	Irritation barely perceptible
	Edema	0	0	2	0	0	0	1	0	1	1	0	1	0	0	0	0	0	0	0	0	0	0	0	0
Control site	Erythema	0	1	0	1	0	1	0	0	1	0	1	0	1	0	1	0	0	0	0	0	0	0	0	0
	Edema	0	1	0	0	0	0	0	0	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

For erythema: 0 = no erythema, 1 = very slight erythema (barely perceptible), 2 = well-defined erythema, 3 = moderate to severe erythema, and 4 = severe erythema (beet redness) to slight eschar formations.
For edema: 0 = no edema, 1 = very slight edema (barely perceptible), 2 = slight edema (edges of area well defined by definite rising), 3 = moderate edema (raised approximately 1 millimeter), and 4 = severe edema.
Evaluation of primary irritation index (PII): 0.00: no irritation, 0.04–0.99: irritation barely perceptible, 1.00–1.99: slight irritation, 2.00–2.99: mild irritation, 3.00–5.99: moderate irritation, and 6.00–8.00: severe irritation.
Data was analyzed by one-way analysis of variance (ANOVA) followed by Tukey’s post hoc test. ^nsnon-significantly different from saline control, < 0.001, when standard irritant and test control (cream base, CEO and B5) were compared with vehicle control. ^a < 0.001, when B5 and CEO were compared with standard irritant.