Carbomer Gel Formulation for LQ Drug Delivery

Carbomer 940 gel does not cause skin irritation and is the vehicle for the drug application in this article. First, 1 g of carbomer 940 powder (Meilunbio, Dalian, China) was mixed with 100 mL of ultrapure water and stirred for 5 min, and then the pH was adjusted to 7.0 with triethanolamine (Macklin, Shanghai, China). Subsequently, three different concentrations of LQ were added to formulate a 1% carbomer gel containing 0.5%, 1%, and 2% (w/v) LQ. The previous step requires stirring at 25 °C until a homogeneous and good-quality gel is formed [38 (link)]. What is more, cold paste (Haixu, Rizhao, China) is pre-made. LQ-CG-CP was prepared by uniformly applying LQ-containing carbomer gel to the cold paste. Its relevant characterization and in vitro drug release assays can be found in Figures S3 and S4 of the Supplementary Materials.