공중합체에 따른 약물 콘택트렌즈의 약물 전달 연구

Study of Drug Delivery from Contact Lens Depending on Copolymers

본 연구에서는 hydroxyethyl methacrylate (HEMA)에 poly(vinyl pyrrolidone) (PVP), poly(N-isopropylacrylamide) (PNIPAAm), 3-(trimethoxysilyl)propyl methacrylate (TRIM)을 공중합하여, pH 변화가 하이드로젤 렌즈에서의 약물 전달 패턴을 분석하였다. 콘택트렌즈는 HEMA와 PVP, PNIPAAm, TRIM의 비율을 달리하여 열 중합하였다. 약물은 인공눈물 점안제제인 hydroxypropyl methylcellulose (HPMC)를 사용하였다. 약물방출량은 UV-spectrophotometer를 이용하여 정량 분석하였다. 그 결과, 음이온성 하이드로젤(p-HEMA, p-HEMA-VP) 렌즈는 용액의 pH가 증가 시 약물의 누적량이 점차 증가하였고, 양이온성 하이드로젤(p-HEMA-NIPAAm) 렌즈에서의 약물 누적량은 감소하였다. 또한 실리콘 함유 렌즈는 실리콘 작용기(-TRIM)의 중합에 따라 실리콘 비함유 렌즈와 반대의 약물 방출 패턴이 나타났다. 이러한 하이드로젤의 이온성 작용반응을 이용하여 눈물의 pH에 선택적으로 약물 전달량을 조절할 수 있는 콘택트렌즈 설계가 가능할 것으로 판단된다

In this study, poly (vinyl pyrrolidone) (PVP), poly (N-isopropylacrylamide) (PNIPAAm) and 3-(trimethoxysilyl) propyl methacrylate (TRIM) were copolymerized with hydroxyethyl methacrylate (HEMA). The effect of pH change on the drug delivery from the polymerized hydrogel lenses was analyzed. Contact lenses were thermally polymerized by varying the ratio of HEMA to PVP, PNIPAAm, and TRIM. Hydroxypropyl methylcellulose (HPMC), a source of artificial tear eye drops was used as a test drug. Drug releasing pattern was analyzed using a UV-spectrophotometer. As a result, the accumulated amount of the drug was gradually increased when the pH was increased in the anionic hydrogel (p-HEMA, p-HEMA-VP) lens. The released drug amount from cationic hydrogel (p-HEMA-NIPAAm) lens was decreased in increased pH. On the other hand, the silicone lens exhibited a drug release pattern opposite to that of the hydrogel lens due to the polymerization of the silicone functional group (-TRIM). This suggests that selective drug delivery from contact lens design is possible through solution-material ionization elationship depending on the polymerization components.