Preparation and Evaluation of Intravaginal Ring Containing Drospirenone

Table 4

Summary of the release data for the matrix-type, reservoir-type, and PVP-SD-treated reservoir IVR containing drospirenone.

Type	Equation of line of best fit	(𝑟) coefficient	Release rate (mg/day)	Burst (mg)
Matrix type	𝑦=1.2063𝑥+9.3079	𝑟=0.9896	1.2063	9.3079
Reservoir type	𝑦=0.5489𝑥+2.0083	𝑟=0.9968	0.5489	2.0083
PVP-SD reservoir IVR	𝑦=0.9504𝑥+5.04843	𝑟=0.9932	0.9504	5.04843

PVP-SD: drospirenone solid dispersion with PVP_k30 as carrier.