Amphiphilic Copolymer of Polyhedral Oligomeric Silsesquioxane (POSS) Methacrylate for Solid Dispersion of Paclitaxel
Round 1
Reviewer 1 Report
This manuscript presented an amphiphilic copolymer for PTX dispersion. however, the authors need to show better quality characterization to support the statement.
XRD needs better quality (better S/N ratio)
The statement of PTX is miscible with MPC-ran-C2H5-POSS is confusing.
The glass transition assignment (Figure S3) is questionable.
FT-IR interpretation is not convincing.
The statement in Page 2 line 70. The authors need to provide the reference to prove the material is not cytotoxic.
Author Response
We would like to re-submit (Full paper ID materials-460041) manuscript entitled “Amphiphilic Copolymer of Polyhedral Oligomeric Silsesquioxane (POSS) Methacrylate for Solid Dispersion of Paclitaxel” for your reconsideration to publish in Materials.
Based on the comments and suggestion made by reviewer 1, we have made changes in the manuscript whereas it was needed. The changes were made inside of manuscript are highlighted as RED for ease of identification. A list of changes and point by point response is added in the uploaded word file. .
Author Response File: 
Author Response.docx
Reviewer 2 Report
In this manuscript by Suchismita Chatterjee et al., the authors report the result of polymerization of MPC and MPC-ran-14 C2H5-POSS )as a carrier for the solid dispersion of PTX. The PTX structure of MPC-ran-C2H5-POSS/PVP/PTX was amorphous, and they could enhance the solubility of PTX by the contribution of the amphiphilic nature of the MPC-ran-C2H5-POSS. It is interesting results, and XRD and other data support the results well. Despite the interesting results, there are some concerns to be clearly addressed.
1． According to the XRD, PTX was amorphous in MPC-ran-C2H5-POSS & PVP. The wt% of PTX of Fig.2 was 12 in all cases. Is 12 wt% the optimization condition? Have you checked relationship of structural characteristics (? Or changes) of PTX as a function of the concentration of PTX in MPC-ran-C2H5-POSS & PVP?
2． In dissolution profile, how did you get the dissolution rate? In case of MPC-ran-C2H5-POSS / PVP / PTX, PTX dissolved 40% before 10 min, and it saturated until 20 min, and then dissolution changed at 20min. As a result, it dissolved 90% at 40 min, and the concentration slowly decreased. Could you explain this complicated dissolution behavior of MPC-ran-C2H5-POSS / PVP / PTX? Except in PVP/PTX case, the dissolution concentration decreased after reaching the maximum point in the other two cases. Why the concentration decreased in MPC-ran-C2H5-POSS/ PVP/PTX and MPC-ran-C2H5-POSS/PTX?
Author Response
We would like to re-submit (Full paper ID materials-460041) manuscript entitled “Amphiphilic Copolymer of Polyhedral Oligomeric Silsesquioxane (POSS) Methacrylate for Solid Dispersion of Paclitaxel” for your reconsideration to publish in Materials.
Based on the comments and suggestion made by reviewer 2, we have made changes in the manuscript whereas it was needed. The changes were made inside of manuscript are highlighted as RED for ease of identification. A list of changes and point by point response is added in the uploaded word file.
Author Response File: Author Response.docx
Reviewer 3 Report
In my opinion, this work on copolymer-based formulations of paclitaxel is interesting and merits publication. However, I do have a few questions concerning the present manuscript:
1) Page 4, Lines 147-151: The authors state that 'the characteristic peaks of PTX were not observed...' The XRD data (Fig. 2a) looks rather noisy, however and only 12 % w/w of PTX was present in the formulation. Consequently, can the authors be sure that the apparent absence of PTX crystal peaks was due to the drug being in an amorphous form - rather than just dilution and poor sensitivity?
Perhaps it would be possible to re-run the XRD measurements at a higher flux or slower scan rate (to get more counts and better statistics).
2) P6, L171-173: Similar questions also arise concerning the FTIR data. Is the apparent absence of PTX peaks in the formulations (Fig. 2c) simply due to dilution?
The differences in spectra between the base polymers and the PTX formulations are very subtle. Would it be possible to highlight the differences in the figure, please?
Also, it would be useful to provide more information on how the FTIR spectra were collected, please. If in ATR mode, the authors should be aware that this is a surface technique (typically collecting data from within only 2 µm of the ATR element surface), which would raise the possibility that the spectrum is not representative of the bulk material.
3) The data in Fig. 3 looks rather imprecise: in particular, the error bars become quite large for some of the later data. Can the authors add suitable comments to the manuscript, please? For example, how was the hplc calibrated for PTX and how accurate were the subsequent measurements?
I presume the data shown in Fig. 3 is based on more than 1 set of measurements. The authors should provide further information in the manuscript.
Also, there were a few typographical or grammatical errors, such as:
L48-49: The intended meaning of the phrase '...should be selected to correct structural and physicochemical nature...' is not clear.
L56: '....(PVP) is extensively subjected for solid dispersions...' Do the authors mean'...(PVP) is extensively used for solid dispersions...'?
L180: '...such the jagged peaks around...'
Author Response
We would like to re-submit (Full paper ID materials-460041) manuscript entitled “Amphiphilic Copolymer of Polyhedral Oligomeric Silsesquioxane (POSS) Methacrylate for Solid Dispersion of Paclitaxel” for your reconsideration to publish in Materials.
Based on the comments and suggestion made by reviewer 3, we have made changes in the manuscript whereas it was needed. The changes were made inside of manuscript are highlighted as RED for ease of identification. A list of changes and point by point response is added in the uploaded word file. .
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The glass transition assignment of Figure S3 is still questionable. For example, curve F, why did you sign 101 deg C as a transition, not 43 deg C. Are these curves on the heating step? If so, curve F has some problem. Are these materials thermally stable at the temperature range you investigated?
Since you are using the Fox equation to demonstrate the dispersion is very good, the Tg assignment must be convincing!
Please also show the full DSC curves of all your samples.
Please also put some guidelines on the FT-IR spectra.
Author Response
We would like to re-submit (Full paper ID materials-460041) manuscript entitled “Amphiphilic Copolymer of Polyhedral Oligomeric Silsesquioxane (POSS) Methacrylate for Solid Dispersion of Paclitaxel” for your reconsideration to publish in Materials.
Based on the comments and suggestion made by reviewers we have made changes in the manuscript whereas it was needed. The changes were made inside of manuscript are highlighted as RED for ease of identification. A list of changes and point by point response is summarized in the attached word file.
Author Response File: Author Response.docx
