Development of Topical/Transdermal Self-Emulsifying Drug Delivery Systems, Not as Simple as Expected

Round 1

Reviewer 1 Report

In this manuscript, the authors focus on the issue of designing self-emulsifying drug delivery systems (SEDDS) for topical/transdermal administration. Comparing SEDDS for oral and topical/transdermal delivery, the authors point out advantages and disadvantages of SEDDS for these administration routes. The manuscript is well organized but some points should be addressed.

Line 159. The meaning of “dosing intervals” is unclear. Does the term “intervals” refer to time or drug concentration?

Line 207. The meaning of the sentence “Nevertheless, it is mentioned in literature that only the cis form of oleic acid can establish enhanced flux of topically applied drugs due to the unsaturated structure of this form of oleic acid” is unclear. The trans form of oleic acid (elaidic acid) is unsaturated as well. Please, correct.

Line 277. The authors wrote the following question, “how can topical/transdermal SEDDSs be optimised in terms of excipient concentrations utilised in addition to achieving spontaneous emulsions?” The authors should address this issue providing their opinion and literature data.

English must be revised. For instance, in many sentences, the use of the word “principal” is incorrect and should be replaced with “principle”.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors prepared a review about the development of topical/transdermal self-emulsifying drug delivery systems, not as simple as expected. The review is well-constructed, but there are some lack of important parts. The authors have to explain the difference among SEDDS, SMEDDS and SNEDDS. I feel that the authors also have to prepare the chapter about the biocompatibility of these dosage forms. Because these systems contain high amount of surfactants and co-surfactants and cytocompatibility is sometimes controversial. 

Author Response

Please see the attachement.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

This improved manuscript was compared with the previous one, it is better.

I accept it without modification.