Photostability studies of retinyl palmitate entrapped in policosanol oleogel matrices
نویسنده
چکیده
............................................................................................................................ xi CHAPTER 1. GENERAL INTRODUCTION ......................................................................... 1 Thesis Organization ............................................................................................................. 1 Literature Review ................................................................................................................ 1 Vitamin A ....................................................................................................................... 1 Retinyl Palmitate ............................................................................................................ 2 Photoreaction of Retinyl Palmitate................................................................................. 2 Strategies to Protect Retinyl Palmitate ........................................................................... 3 Oleogels .......................................................................................................................... 6 Oleogel as Bioactive Carrier .......................................................................................... 7 Policosanol ..................................................................................................................... 8 Previous Studies on Policosanol Oleogel ....................................................................... 9 Importance of this Research .............................................................................................. 10 Project Structure ................................................................................................................ 11 References.......................................................................................................................... 11 CHAPTER 2. KINETIC STUDY ON PHOTOSTABILITY OF RETINYL PALMITATE ENTRAPPED IN POLICOSANOL OLEOGELS .......................................... 16 Abstract .............................................................................................................................. 16............................................................................................................................. 16
منابع مشابه
Photodecomposition and Phototoxicity of Natural Retinoids
Sunlight is a known human carcinogen. Many cosmetics contain retinoid-based compounds, such as retinyl palmitate (RP), either to protect the skin or to stimulate skin responses that will correct skin damaged by sunlight. However, little is known about the photodecomposition of some retinoids and the toxicity of these retinoids and their sunlight-induced photodecomposition products on skin. Thus...
متن کاملSubstrate specificity of retinyl ester hydrolase activity in retinal pigment epithelium.
In the eye, hydrolysis of stored retinyl esters is catalyzed by retinyl ester hydrolase (REH) activities in retinal pigment epithelium (RPE) membranes. In the present study, biochemical analyses were conducted to determine the substrate specificity of these activities. Specific activities determined for hydrolysis of various retinol isomers of retinyl palmitate (9-cis-, 11-cis-, 13-cis-, and al...
متن کاملPlasma clearance of chylomicrons labeled with retinyl palmitate in healthy human subjects.
To estimate hepatic uptake of chylomicron remnants in humans, chylomicrons and intestinal very low density lipoproteins (VLDL) were endogenously labeled with retinyl esters, harvested by plasmapheresis, and pulse-injected into the donor 44 hr after plasmapheresis. Plasma decay of retinyl palmitate was measured in eight healthy volunteers. Retinyl palmitate plasma disappearance obeyed an apparen...
متن کاملHydrolysis of 11-cis- and all-trans-retinyl palmitate by homogenates of human retinal epithelial cells.
The retinal epithelium plays an important role in the storage and metabolism of retinoids in the eye. Studies were conducted to examine the enzymatic hydrolysis of retinyl esters by human retinal epithelial cells. Homogenates prepared from these cells were found to hydrolyze both the 11-cis- and all-trans-isomers of retinyl palmitate. Retinyl ester hydrolysis was time-, protein-, and pH-depende...
متن کاملPlasma decay of chylomicron remnants is not affected by heparin-stimulated plasma lipolytic activity in normal fasting man.
In an earlier study it was shown that retinyl palmitate appeared to be a satisfactory label for the core of chylomicrons and their remnants. When chylomicrons were endogenously labeled with retinyl palmitate and pulse-injected into healthy donors, retinyl palmitate was cleared from plasma by a first order process. Its fractional decay constant was very similar to the fractional catabolic rate o...
متن کامل