Next Article in Journal
Nanoemulsions of Satureja montana Essential Oil: Antimicrobial and Antibiofilm Activity against Avian Escherichia coli Strains
Next Article in Special Issue
Pharmacokinetic Estimation Models-based Approach to Predict Clinical Implications for CYP Induction by Calcitriol in Human Cryopreserved Hepatocytes and HepaRG Cells
Previous Article in Journal
Comparison of Genetically Engineered Immunodeficient Animal Models for Nonclinical Testing of Stem Cell Therapies
Peer-Review Record

Model-Based Prediction to Evaluate Residence Time of Hyaluronic Acid Based Dermal Fillers

Pharmaceutics 2021, 13(2), 133;
by Hyo-jeong Ryu 1,2, Seong-sung Kwak 1, Chang-hoon Rhee 3, Gi-hyeok Yang 1,3, Hwi-yeol Yun 2,*,† and Won-ho Kang 1,2,*,†
Reviewer 1: Anonymous
Reviewer 2: Anonymous
Pharmaceutics 2021, 13(2), 133;
Submission received: 14 December 2020 / Revised: 14 January 2021 / Accepted: 18 January 2021 / Published: 21 January 2021
(This article belongs to the Special Issue Model-Informed Drug Discovery and Development)

Round 1

Reviewer 1 Report

Dear authors.


Please address these points:


  1. we have zero information about these materials. Are they HA only? are they modified HA, Have they been crosslinked. What is the MW of each? Without this informatin these modelling results are meaningless.

2. equations 1-6 are very poorly presented

3. figure is extremely poor and impossible to analyse

4. what is the decomposition mechanism? This discussion could be expanded and explained using Soltes work 

Carbohydrate polymers 134, 516-523

Carbohydrate polymers 148, 189-193

5. a deeper discussion is required using info from question 1 above.

6.  a recent HA modification would be useful in the introduction to guide readers to the latest advances in the field

Carbohydrate Polymers, 116501

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report


The submitted paper deals with the experimental campaign carried out on the commercial hyaluronic acid based dermal fillers, aiming to provide a mathematical model for the balance between swelling and degradation. Results are interesting and highlight the inter-individual variations in the mid-long term after subcutaneous injections of the dermal fillers. Overall, this is an elegant characterization work with well-structured aims and conclusions. In my opinion, it can be published after some minor changes are made. In the following, there are some detailed considerations.

  • In the definition of model equations, is SC volume coincident with the injected volume? For the reader’s convenience, the units should also be defined (mm3, cm3…)
  • Maybe I did not get the point, but I assume a circular geometry has been defined. If so, please clarify.
  • Normally, the swelling ratio of gels is calculated starting from the dried xerogel. I think that the tested HA-based dermal fillers are in the hydrated state immediately before injection. Is there any information about the solid fraction of each of the gel? What is the initial swelling degree of the tested dermal fillers at the moment of injection?
  • The image resolution of the model equations should be enhanced.
  • Could the diameter of the needle syringe influence the volume of the dermal filler injected and, subsequently, the swelling kinetics and biodegradation? Is there any standard? If so, please specify.
  • Why did the authors choose eight mice for each group? How was the number established?

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

authors have answered questions

Back to TopTop