Development of a Solid Supersaturable Micelle of Revaprazan for Improved Dissolution and Oral Bioavailability Using Box-Behnken Design

Figures & data

Figure 1 Solubility of RVP in various surfactant solutions (1% [w/w]) (A) and CMC determination via the solubilization method (B).

Abbreviations: LG, Lauroglycol 90; LF, Labrafil M 1944 CS; BL4, Brij L4; LS, Labrasol; RH60, Kolliphor RH60; RH40, Kolliphor RH40; G44, Gelucire 44/14; EL, Kolliphor EL; T80, Tween 80; T20, Tween 20.

Figure 2 Dissolution profiles of micelle with or without various supersaturating agents.

Note: *p <0.05 versus Micelle only.

Abbreviations: P407, Poloxamer 407; K90, Kollidon K90; P188, Poloxamer 188; K30, Kollidon K30.

Figure 3 Plots of the CI against the ratio of solid carrier to SuM to evaluate flow property changes in SuM formulations with silica-based adsorbents (A) and cellulose-based diluents (B).

Note: Arrows indicate the critical solidifying ratio.

Abbreviations: FLO, Florite PS-10; VP105, Vivapur 105; VP12, Vivapur 12; L-HPC, low-substituted hydroxypropyl cellulose B1.

Table 1 Independent and Response Variables Used in Box-Behnken Design

Independent Variables		Levels
		–1	0	1
X1	G44/BL4	1:0	1:1	0:1
X2	FLO (mg)	60	90	120
X3	VP105 (mg)	180	240	360
Response variables		Goal
Y1	DE30 (%)	Maximized
Y2	DEC	Maximized
Y3	CI (%)	Minimized

Abbreviations: G44, Gelucire 44/14; BL4, Brij L4; FLO, Florite PS-10; VP105, Vivapur 105; DE₃₀, dissolution efficiency at 30 min; DEC, dissolution enhancing capacity DE₃₀, dissolution efficiency at 30 min; DEC, dissolution enhancing capacity; CI, Carr’s index.

Table 2 Combinations of Independent Variable and Experimental Responses from Runs

Run	X1	X2	X3	Y1	Y2	Y3
1	–1	–1	0	38.14 ± 2.15	0.093 ± 0.002	17.9 ± 0.4
2	1	–1	0	28.75 ± 2.78	0.084 ± 0.006	19.6 ± 0.5
3	–1	1	0	26.45 ± 2.76	0.085 ± 0.004	11.5 ± 0.8
4	1	1	0	21.23 ± 4.97	0.062 ± 0.006	12.6 ± 0.4
5	–1	0	–1	42.09 ± 2.13	0.086 ± 0.006	15.4 ± 0.3
6	1	0	–1	33.61 ± 3.58	0.058 ± 0.008	15.8 ± 0.6
7	–1	0	1	34.44 ± 4.16	0.060 ± 0.005	12.4 ± 0.1
8	1	0	1	29.97 ± 7.43	0.050 ± 0.006	13.7 ± 0.5
9	0	–1	–1	45.56 ± 1.87	0.097 ± 0.002	20.6 ± 0.1
10	0	1	–1	31.67 ± 1.72	0.080 ± 0.002	10.5 ± 0.6
11	0	–1	1	33.85 ± 1.28	0.086 ± 0.005	14.9 ± 0.3
12	0	1	1	27.67 ± 2.86	0.063 ± 0.004	10.2 ± 0.4
13	0	0	0	34.60 ± 2.38	0.089 ± 0.005	13.0 ± 0.5
14	0	0	0	36.62 ± 1.05	0.091 ± 0.006	13.4 ± 0.5
15	0	0	0	35.84 ± 0.97	0.091 ± 0.005	12.9 ± 0.9

Notes: X_1, G44:BL4; X₂, FLO; X₃, VP105; Y₁, DE₃₀; Y₂, DEC; Y_3, Carr’s index; Values are presented as the mean ± SD (n = 3).

Table 3 Summary of the Results of Statistical Analysis and Model Equations for the Measured Responses

Models	S	R^2	R^2 (Adj)	p-value	Lack of Fit p-value	Remark
DE30 (%)
Linear	4.333	59.61	56.66	<0.001	<0.001	-
Linear+square	3.243	79.03	75.72	<0.001	0.286	-
Linear+interaction	4.293	63.27	57.47	<0.001	<0.001	-
Quadratic	3.071	82.69	78.4	<0.001	0.835	Suggested
DEC
Linear	0.011	48.61	44.85	<0.001	<0.001	-
Linear+square	0.006	88.60	86.80	<0.001	0.008	-
Linear+interaction	0.011	52.56	45.07	<0.001	<0.001	-
Quadratic	0.005	92.55	90.63	<0.001	0.439	Suggested
CI (%)
Linear	1.217	85.26	84.18	<0.001	<0.001	-
Linear+square	0.925	92.10	90.86	<0.001	<0.001	-
Linear+interaction	0.996	90.85	89.41	<0.001	<0.001	-
Quadratic	0.521	97.69	97.10	<0.001	0.157	Suggested

Abbreviations: DE₃₀, dissolution efficiency at 30 min; DEC, dissolution enhancing capacity; CI, Carr’s index; S, standard error of regression.

Table 4 Analysis of Variance of the Experimental Responses for Quadratic Model

Source	DF	Y1 (DE30)			Y2 (DEC)			Y3 (CI)
		SS	F	p-value	SS	F	p-value	SS	F	p-value
Model	9	1576.29	18.57	< 0.001	0.009534	48.30	< 0.001	402.43	164.55	< 0.001
Residual	35	330.03	-	-	0.000768	-	–	9.51	-	–
Total	44	1906.32	-	-	0.010302	-	-	411.97	-	-
Lack of fit	3	8.63	0.29	0.835	0.000061	0.93	0.439	1.41	1.86	0.157

Abbreviations: DF, degrees of freedom; SS, sum of squares, DE₃₀, dissolution efficiency at 30 min; DEC, dissolution enhancing capacity; CI, Carr’s index.

Figure 4 Effects of independent factors on response variables: three-dimensional response surface plots of Y₁ (A), Y₂ (B), and Y₃ (C).

Table 5 Predicted Values and Experimental Values for the Optimized RVP-Loaded SSuM Formulation

Y Variables	DE30	DEC	CI
Predicted value	38.6	0.09	12.9
Experimental value	40.3	0.088	12.3
Prediction error (%)	4.40	−2.22	–4.65

Notes: Optimized SSuM contains 200 mg RVP, 253.8 mg G44, 106.2 mg BL4, 99.3 mg FLO, 199.8 mg VP105, and 40 mg P407.

Abbreviations: DE₃₀, dissolution efficiency at 30 min; DEC, dissolution enhancing capacity; CI, Carr’s index.

Figure 5 Solid-state properties of powders. (A) Scanning electron microscopy images. (B) Differential scanning calorimetry thermograms. (C) Powder X-ray diffractometry patterns.

Note: Scale bar = 10 μm.

Abbreviations: RVP, revaprazan; FLO, Florite PS-10; VP105, Vivapur 105; PM, physical mixture of RVP and solid carriers; SSuM, solid supersaturable micelle.

Figure 6 Dissolution profiles of raw RVP, Revaprazan^® (powder), solid micelle, and the optimized SSuM in distilled water.

Note: Values are the mean ± standard error (n = 3).

Abbreviations: RVP; revaprazan; SSuM, solid supersaturable micelle.

Figure 7 Plasma RVP concentration profiles after oral administrations of different formulations to Sprague-Dawley rats at an equivalent dose of 20 mg/kg of RVP.

Note: Values are the mean ± standard deviation (n = 6–8).

Abbreviations: RVP, revaprazan; SSuM, solid supersaturable micelle.

Table 6 PK Parameters of RVP Formulations in Rats

Parameters	Raw RVP	Revanex^®	Solid Micelle	SSuM
AUC0–24h (ng·h/mL)	1662.36 ± 547.06	2877.84 ± 564.18*	4940.90 ± 1591.37*,^#	7941.48 ± 1608.03*,^#,†
Cmax (ng/mL)	195.50 ± 82.23	339.50 ± 51.10*	619.35 ± 160.54*,^#	987.54 ± 171.38*,^#,†
Tmax (h)	5.00 ± 2.10	4.92 ± 2.25	4.92 ± 1.86	6.00 ± 1.79
Relative BA (%)
versus raw RVP	–	173.1	297.2	477.7
versus Revanex^®	57.8	–	171.7	276.0
versus Solid micelle	33.6	58.2	–	160.7

Notes: Significantly different at p <0.05, *versus RVP; ^#versus Revanex^®; ^†versus solid micelle.

Abbreviations: AUC, area under the curve; BA, bioavailability; RVP, revaprazan; SSuM, solid supersaturable micelle.