Perioli Luana, Ambrogi Valeria, Bertini Barbara, Ricci Maurizio, Nocchetti Morena, Latterini Loredana, Rossi Carlo
Dipartimento di Chimica e Tecnologia del Farmaco, Università degli Studi di Perugia, Perugia, Italy.
Eur J Pharm Biopharm. 2006 Feb;62(2):185-93. doi: 10.1016/j.ejpb.2005.08.001. Epub 2005 Oct 3.
The use of sunscreen preparations is recently growing and their efficacy and safety must be taken into account since they are applied on the skin frequently and for many hours. Exposition to sunlight, in fact, can cause sunscreen photodegradation and determine their decrease in UV protection often with the occurrence of allergic and/or toxic degradation products. A high photostability is hence very important for their effectiveness and safety. The aim of this work is to obtain new sunscreen formulations stabilized by intercalating PABA, within the lamellar structures of two kinds of hydrotalcite. PABA was chosen as model sunscreen because of its high photoinstability and photosensitizing properties that nowadays bar its utilization. Both intercalated products showed an increased protection range and, in one case, an improved sunscreen photostability. Sunscreen release from creams containing intercalated or free PABA was evaluated as well. The very low or negligible sunscreen release, obtained from the intercalated product loaded formulations, resulted in a lack of a close contact between skin and filter with the consequence that cutaneous reactions and allergy problems are eliminated. The use of these materials resulted in a good strategic technological approach in order to increase efficacy and safety of solar products.
近年来，防晒制剂的使用日益增加，由于它们经常长时间涂抹于皮肤上，因此必须考虑其功效和安全性。事实上，暴露于阳光下会导致防晒剂发生光降解，并常常因产生过敏和/或有毒降解产物而使其紫外线防护能力下降。因此，高光稳定性对其有效性和安全性非常重要。这项工作的目的是通过将对氨基苯甲酸（PABA）插层到两种水滑石的层状结构中，获得新型稳定的防晒配方。选择PABA作为模型防晒剂是因为其高光不稳定性和光敏特性，这些特性目前限制了它的使用。两种插层产物均显示出防护范围扩大，在一种情况下，防晒剂的光稳定性有所提高。还评估了含插层或游离PABA的乳膏中防晒剂的释放情况。从含插层产物的配方中获得的极低或可忽略不计的防晒剂释放量，导致皮肤与滤光剂之间缺乏紧密接触，从而消除了皮肤反应和过敏问题。使用这些材料为提高防晒产品的功效和安全性提供了一种良好的策略性技术方法。
