8.3.2.4　The dosage form of drugs

The dosage form of topical medication has a significant effect on transdermal absorption.It is generally believed that the efficiency of drug penetration in gels，emulsions，ointments，plasters and creams is superior to that in powders and aqueous solutions.

In addition to the factors mentioned above，the dissociation degree，melting point and pH of drugs also affect its transdermal efficiency.(https://www.daowen.com)