#TITLE_ALTERNATIVE#

• Main Author: Simanjuntak (NIM 107 03 032), Ronal
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/6711
• Institution: Institut Teknologi Bandung

Abstract : <br /> <br /> <br /> <br /> Vitamin C is used topically as an antioxidant and precursor of synthesis collagen to prevent aging. Vitamin C must diffuse through skin in order to reach dermis in which collagen is synthesized. The aim of this research is to study the influence of pH in cream and gel on diffusion rate of vitamin C. Gel and cream were made in variation of pH (pH 3, 5, and 7). Diffusion profile of vitamin C was determined by using diffusion cells. The amount of vitamin C diffused through membrane was measured at certain time interval for 180 minutes at 37+/-1 C. Quantitative analysis of vitamin C was done with UV spectrophotometri at 266 nm. The amount of vitamin C diffused through membrane in descending order is: gel with pH 3 (4,57+/-0,50%), pH 5 (3,62+/-0,57%), pH 7 (2,80+/-0,49%), cream pH 3 (2,74+/-0,47%), pH 5 (2,15+/-0,48%) and pH 7 (2,12+/-0,42%). Diffusion rate of vitamin C in gel and cream is decreased as pH increases. Percent diffusion of vitamin C in gel is higher than in cream. <br />