32 DAFTAR PUSTAKA Agoes, G. , S. T. Darijanto, 1990, Teknologi Farmasi Likuida dan Semi Solida, Pusat Antar Universitas Bidang Ilmu Hayati, Institut Teknologi Bandung, 73-86. Baumann, Leslie, 2002, Cosmetic Dermatology : Principles and Practice, The McGraw- Hill Companies, New York, 3-59, 105, 109. Bojar, R. A. and Keith H. Holland, 2004, Acne and Propionibacterium acnes. J. Clin Dermatol., 22, 375-379. Chen, H. X, D. Du Chang, and X. Yang, 2006, Microemulsion-based hydrogel formulation of ibuprofen for topical delivery, Inter.