1. US 21 Code of Federal Regulations, Section 320.
2. Ueda CT, Shah VP, Derdzinski K, et.al. Performance test for topical and transdermal dosage forms. Pharmacop Forum. 2006;32(5):1586–9.
3. US Food, Drug and Cosmetic Act, Sec 301; 21 USC 331.
4. Guy RH, Guy AH, Maibach HI, Shah VP. The bioavailability of dermatological and other topically administered drugs. Pharm Res. 1986;3:253–62.
5. United States Pharmacopeial Convention, USP/NF 36/31, General chapters <3>, <724> and <1724>.