ISSN - 0975-7058 Special Issue (October) EFFECT OF OPTIMIZATION OF TWEEN 80 AND PROPYLENE GLYCOL AS A SURFACTANT AND COSURFACTANT ON THE PHYSICAL PROPERTIES OF ASPIRIN MICROEMULSION KORI YATI*, YUDI SRIFIANA, FARENSYAH PUTRA Department of Pharmacy, Faculty of Pharmacy and Science, University of Muhammadiyah, Jakarta, Indonesia. Email: koriyati@ymail.com Received: 21 April 2017, Revised and Accepted: 13 July 2017 ABSTRACT Background: Aspirin is recommended as a first-line antiplatelet drug for all types of acute diseases that cause thrombosis in the blood vessel, especially in cardiovascular disease. Orally administered aspirin has side effects such as the risk of gastrointestinal bleeding and has presystemic metabolism in the gastrointestinal tract and liver. Transdermal delivery offers an alternative for administering aspirin that by passes the gut and this may be more convenient and safe for long-term use. This study used a form of microemulsion to prevent hydrolysis of aspirin because it contains a high concentration of the surfactant. A microemulsion is a dosage form that can penetrate into the skin for transdermal delivery. Objectives: The aim of this research was to evaluate the effect of Tween 80 and propylene glycol as the surfactant and cosurfactant on the physical stability of the microemulsion. Materials and Methods: Various concentrations of Tween 80 and propylene glycol (2:1) were used 54%, 57%, 60%, and 63%, and the physical stability of the different microemulsions was tested for 6 weeks. Result: The results showed that the formula F3 was the most stable formula. The formula F3 showed the following properties such as pH of 3.74±0.30, viscosity of 1198.76±56.02 cps, BJ of 1.0669±0.005 g/mL, surface tension of 38.77±0.43 dyne/cm, and particle size of 49.46±6.91 nm. Conclusions: Based on the results concluded that the optimum concentration of Tween 80 as the surfactant and propylene glycol as the cosurfactant with a ratio of 2:1 was 60%. Keywords: Aspirin, Transdermal, Microemulsions, Tween 80. INTRODUCTION Aspirin is a nonsteroidal anti-inflammatory drug that is efficient as an antiplatelet because it can inhibit the activity of the enzyme cyclooxygenase in platelets. Orally administered aspirin has side effects such as the risk of gastrointestinal bleeding and has presystemic metabolism in the gastrointestinal tract and liver. This situation is exacerbated by the continued use of aspirin that can causes serious side effects in the gastrointestinal tract. In view of the poor effectiveness of oral administration, a transdermal drug delivery system is an alternative method that can improve the effectiveness of aspirin use [1,2]. Transdermal delivery by passes the gut and may, therefore, be more convenient and safe for long-term use. A microemulsion is a dosage form used for penetration in transdermal delivery. It contains a surfactant, so it is fine when formulated with aspirin because aspirin is a drug that can be hydrolyzed in the presence of water. The presence of a surfactant can prevent hydrolysis of aspirin by protecting it in micelles that can obstruct the entry of hydroxyl groups that attack the ester groups [3]. The surfactants used in this study were Tween 80. Surfactants help in forming oil-in-water microemulsions with a cosurfactant, which improves the solubilization. Short to medium chain length alcohols (C3-C8) are commonly added as cosurfactants, which further reduce the interfacial tension and fluidity of the interface. This study used propylene glycol as the cosurfactant. The aim of this study was to investigate the effect of Tween 80 and propylene glycol as a surfactant and cosurfactant on the physical properties of aspirin microemulsions. MATERIALS AND METHODS Materials Aspirin was purchased from of Yixing City, Xingyu. Virgin coconut oil was purchased from LIPI Cibinong, Bogor. Tween 80 was purchased from PT. KAO Chemical. Propylene glycol was purchased from PT. Dow Chemical Pacific. Methylparaben and Propylparaben were purchased from PT. Clariant. Pseudoternary phase diagram construction For preparing the microemulsion first, preliminary experiments were first carried out using pseudoternary phase diagrams. In the preliminary experiments, the microemulsion formula was optimized with virgin coconut oil as the oil phase, a combination of Tween 80 and propylene glycol (2:1) as the surfactant and cosurfactant, and distilled water as the aqueous phase. Preparation of aspirin microemulsions Various microemulsions were chosen from the pseudoternary phase diagrams. The concentration of virgin coconut oil was 5%, and combination (54%, 57%, 60%, and 63%) of Tween 80, and propylene glycol (2:1) concentrations were used. Aspirin was dispersed in the virgin coconut oil as the oil phase and then added to a mixture of distilled water and Tween 80. Then, propylene glycol was added to form a clear and homogeneous mixture (Table 1). Organoleptic Organoleptic includes observation of the shape, clarity, and smell. Observations were carried out for 6 weeks, on weeks 0, 3, and 6. Research Article PTMDS 2017 | The 1 st Physics and Technologies in Medicine and Dentistry Symposium © 2017 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4. 0/) DOI: http://dx.doi.org/10.22159/ijap.2017.v9 s1 .71_78