Solid Dispersions of Gefitinib with D-α-Tocopherol Polyethylene Glycol-1000 Succinate and 2-Hydroxypropyl β-Cyclodextrin Complex Improved Their Solubility, Dissolution and Apoptosis against A549 Cells

Round 1

Reviewer 1 Report

. Page 3, section 2.2.1, quantitative analysis of GEF, the authors mentioned that ''The retention time for GEF was 6.545 min.These results established a linearity between the peak area and the concentration of GEF and the method was successfully applied for the quantitative determination of GEF in the present study''. Authors cannot mention the results in the method section. these sentences must be rewrite and results should be mentioned in results section.

 2. Brief describe the HPLC method development results in Results and discussion section.

3. Why authors prepare only 1 formulation with TPGS and SLS? in my opinion, for optimization purpose, at least 3 formulations of SDs with each TPGS and SLS must be prepared.

4. In Figure 1, the figure of release profile of all formulations, only F1 is mentioned in red color, all other formulations are similar in symbol, cannot differentiate. Please clarify and highlight the difference in F2, F3 and GEF-Pure in figure 1.

5. Figure 3, the authors must present the FTIR spectra in overlay form to differentiate all the formulations. The authors did not mention the FTIR of SLS pure.

6. In figure 7, SEM, there is no pure SEM of HPB-CD. Need to place in figure 7.

7. The authors mentioned in whole manuscript, the SDs were prepared by co-precipitation, solvent evaporation followed by freeze drying.  But authors did not mention that either they used 1 method or 2 methods to prepare SDs? because the authors mentioned only 3 formulations and did not highlight any method. need to clarify.

Author Response

Comments and Suggestions for Authors by Reviewer #1

 

Response: The authors are thankful to the reviewer’s comments and suggestions. We have revised the manuscript by considering the reviewer’s valuable suggestions. The changes were highlighted with yellow texts in the revised version.

 

1. Page 3, section 2.2.1, quantitative analysis of GEF, the authors mentioned that ''The retention time for GEF was 6.545 min. These results established a linearity between the peak area and the concentration of GEF and the method was successfully applied for the quantitative determination of GEF in the present study''. Authors cannot mention the results in the method section. these sentences must be rewrite and results should be mentioned in results section.

Response: Thank you for this suggestion. The results of the HPLC method for the analysis of Gefitinib have been removed from the method section. Now it has been presented separately in results and discussion section. 

 

2. Brief describe the HPLC method development results in Results and discussion section.

Response: A brief description of the referred HPLC for the analysis of GEF has been included in the revised manuscript as 3.1 HPLC Analysis of GEF: The adopted HPLC method [16] was found to give linear calibration curve at these concentrations with correlation coefficient (R²) of 0.9997 and regressed equation of “y = 101575x – 80100”. The retention time for GEF was 6.545 min. The sensitivity in terms of limit of detection (LOD) and limit of quantification (LOQ) of this method was reported as 1.3 and 3.9 µg/mL, respectively. The accuracy in terms of recovery (%) of quality control samples were 98.5–101.2% with 1.09–1.56% of RSD (%), while the RSD (%) of peak area were 0.23–1.22% and 0.12–1.56% for intra-day and inter-day precision, respectively. As the RSD (%) of peak areas were less than 2%, the method was considered as accurate and reproducible [16]. These results established a linearity between the peak area and the concentration of GEF and the method was successfully applied for the quantitative determination of GEF in the present study.

 

 

3. Why authors prepare only 1 formulation with TPGS and SLS? in my opinion, for optimization purpose, at least 3 formulations of SDs with each TPGS and SLS must be prepared.

Response: Thanks for pointing out this. The formulations were developed with varying concentrations of the surfactants and HP β-CD. The concentration of GEF was kept constant. For each group, we have developed three formulations. Based on the value of percentage yield (%) and cumulative drug release (%), the optimal one from each group (such as F1, F2 and F3) was selected for further investigation. The formulation development for optimization purpose has been supplied as a Supplementary material (Table S1 and Figure S1).

 

4. In Figure 1, the figure of release profile of all formulations, only F1 is mentioned in red color, all other formulations are similar in symbol, cannot differentiate. Please clarify and highlight the difference in F2, F3 and GEF-Pure in figure 1.

Response: Thanks for the valuable suggestion. In Figure 1, the release profiles of different formulations have been represented with different color with different symbols. Now they can be differentiated well for comparison purpose.

 

5. Figure 3, the authors must present the FTIR spectra in overlay form to differentiate all the formulations. The authors did not mention the FTIR of SLS pure.

Response: Authors are thankful to the reviewer for this nice suggestion. The FTIR spectra of all excipients and formulations have been presented in overlay form (represented as Figure 3 in the revised manuscript). Also, the FTIR of pure SLS has been included now.

 

6. In figure 7, SEM, there is no pure SEM of HPB-CD. Need to place in figure 7.

Response: The SEM of pure HP β-CD has been included now in Figure 7.

 

7. The authors mentioned in whole manuscript, the SDs were prepared by co-precipitation, solvent evaporation followed by freeze drying.  But authors did not mention that either they used 1 method or 2 methods to prepare SDs? because the authors mentioned only 3 formulations and did not highlight any method. need to clarify.

Response: We are thankful to the reviewer for highlighting the error. Actually we have developed the formulation (SD) by co-precipitation method, where the extra organic solvent was evaporated by magnetic stirring. Finally, the developed SDs were dried by freeze-drying method for further characterization. To avoid any confusion, we have corrected these in the revised manuscript.

Reviewer 2 Report

The authors have developed solid dispersions of Gefitinib with different excipients. Generally, this manuscript is interesting with good data presentation and the originality of the research. However, some typos, unsuitable words, grammatical errors are found here. Thus, I would recommend a moderate English editing. Here are some comments for improving the quality of this research.

- Please check the grammar of the Title.

- Please check the word number. The abstract should not be more than 200 words.

- Please give the full term of the word before using abbreviations.

- There is no aim and general conclusion in the abstract. Please make it as a structured abstract.

- Please check the appropriateness of chosen words, such as Further and shortest in the abstract.

- In the introduction, when authors mention poor oral bioavailability, poor aqueous solubility, limited intestinal permeability, low dissolution rate, these should be followed by data/number. Please add these in the manuscript.

- Introduction - Paragraph 2: It is written "to improve pharmacological activity". Why did the authors mention about this? The previous explanations in the paragraph are about bioavailability not the pharmacological activity. Please explain about this statement.

- Please avoid using quotation mark ("..") in the brand of the product and some inappropriate places. Just type it normally.

- Did the authors do the analytical method validation or use a validated method by other researcher? Please indicate the LOD, LOQ, Accuracy and precision of the HPLC method.

- Table 1 should appear after section 2.2.2.

- Some units are incorrect, for example in the Section 2.2.3, it is written "using 0.45 µ". µm? Also, the degree symbols in temperature should not be underlined.

- In the in vitro dissolution study, please mention the predetermined time intervals clearly.

- SEM: The method should be completed with voltage and other parameters.

- Section 2.2.5.5. Micrometrics - should be micromeritics.

- In terms of results and discussion, some of the results presented have not been discussed. For instance, the results in Table 1 and 2, the authors only mention the data without elaborating the reasons why it happenned.

- For FTIR & DSC, these results should be compared with the works of other and more discussed.

- Figure 6 should be completed with annotations.

A moderate editing in Englis is required.

Author Response

Comments and Suggestions for Authors by Reviewer #2

 

The authors have developed solid dispersions of Gefitinib with different excipients. Generally, this manuscript is interesting with good data presentation and the originality of the research. However, some typos, unsuitable words, grammatical errors are found here. Thus, I would recommend a moderate English editing. Here are some comments for improving the quality of this research.

Response: The authors are thankful to the reviewer’s comments and suggestions. We have revised the manuscript by considering the reviewer’s valuable suggestions. The changes were highlighted with yellow texts in the revised version.

 

- Please check the grammar of the Title.

Response: Thanks for the suggestion. As per the suggestion we have modified the title as “Solid Dispersions of Gefitinib with D-α-Tocopherol Polyethylene Glycol-1000 Succinate and 2-Hydroxypropyl β-Cyclodextrin Complex Improved their Solubility, Dissolution and Apoptosis Against the A549 Cells”.

 

- Please check the word number. The abstract should not be more than 200 words.

Response: The abstract has been modified as per the suggestion.

 

- Please give the full term of the word before using abbreviations.

Response: Corrected as per the suggestions.

 

- There is no aim and general conclusion in the abstract. Please make it as a structured abstract.

Response: The abstract has been revised as per the suggestion. The aim of the study was mentioned and a general conclusive statement was added in the abstract.

 

- Please check the appropriateness of chosen words, such as Further and shortest in the abstract.

Response: Thanks for the kind suggestion. In the modified abstract we have removed these words.

 

- In the introduction, when authors mention poor oral bioavailability, poor aqueous solubility, limited intestinal permeability, low dissolution rate, these should be followed by data/number. Please add these in the manuscript.

Response: As per the suggestion the possible data have been included and the references were also updated in the revised version.

The inclusions are as follows; for poor oral bioavailability (not more than 60%)

For poor aqueous solubility (approximately 0.3 mg/mL in ethanol and 0.5 mg/mL in 1:1 v/v solution of DMSO and PBS of pH 7.2).

The term limited intestinal permeability has been removed from the manuscript, because GEF belongs to BCS class-II drug (low solubility and high permeability). It means it doest not have permeability issue.

For low dissolution rate (approximately 41.13% from API of pure GEF).

 

- Introduction - Paragraph 2: It is written "to improve pharmacological activity". Why did the authors mention about this? The previous explanations in the paragraph are about bioavailability not the pharmacological activity. Please explain about this statement.

Response: We are thankful for pointing the mistake. We have not performed any pharmacological/pharmacodynamic activity in the present work. Therefore, the term “pharmacological activity” has been removed from the second paragraph of introduction part. The sentence has been revised as: Therefore, it was mandatory to develop a formulation with better solubility, dissolution and absorption to enhance the oral bioavailability of GEF.

 

- Please avoid using quotation mark ("..") in the brand of the product and some inappropriate places. Just type it normally.

Response: Thanks for the suggestion. We have removed the quotation marks in the brand names and other places.

 

- Did the authors do the analytical method validation or use a validated method by other researcher? Please indicate the LOD, LOQ, Accuracy and precision of the HPLC method.

Response: Thanks for the comment. We have used a previously reported validated HPLC method for the quantitative analysis of GEF in the present investigation. The LOD, LOQ, accuracy and precision of the reported HPLC method have been included in revised manuscript, which as:

3.1 HPLC Analysis of GEF: The adopted HPLC method [16] was found to give linear calibration curve at these concentrations with correlation coefficient (R²) of 0.9997 and regressed equation of “y = 101575x – 80100”. The retention time for GEF was 6.545 min. The sensitivity in terms of limit of detection (LOD) and limit of quantification (LOQ) of this method was reported as 1.3 and 3.9 µg/mL, respectively. The accuracy in terms of recovery (%) of quality control samples were 98.5–101.2% with 1.09–1.56% of RSD (%), while the RSD (%) of peak area were 0.23–1.22% and 0.12–1.56% for intra-day and inter-day precision, respectively. As the RSD (%) of peak areas were less than 2%, the method was considered as accurate and reproducible [16]. These results established a linearity between the peak area and the concentration of GEF and the method was successfully applied for the quantitative determination of GEF in the present study.

 

- Table 1 should appear after section 2.2.2.

Response: As per the suggestion, Table 1 has been shifted after the section 2.2.2.

 

- Some units are incorrect, for example in the Section 2.2.3, it is written "using 0.45 µ". µm? Also, the degree symbols in temperature should not be underlined.

Response: The unit for pore size has been corrected as "0.45 µm”. The symbol of degree centigrade (°C) for temperature has been corrected wherever it was wrongly typed.

 

- In the in vitro dissolution study, please mention the predetermined time intervals clearly.

Response: The predetermined time points selected for the in vitro release study was as follows: 0, 5, 10, 15, 30, 45, 60, 90 and 120 minutes

 

- SEM: The method should be completed with voltage and other parameters.

Response: The method for SEM has been updated in the revised manuscript. The morphology of GEF-pure, PM, F1, and F3 was assessed was assessed through scanning electron microscopy (SEM). The SEM (Zeiss EVO LS10, Cambridge, UK) was done using the gold-sputter technique. Herein, the gold coating was done on the dried samples using the “Q-150R Sputter Unit” of “Quorum Technologies Ltd. (East Sus-sex, UK)”. The coating was done for 1 minute at 20mA current in an Argon atmosphere. Finally, the imaging was done at working distance of 15 mm, accelerating voltage of 10-20 kV and the magnification was 500-2000 times.

 

- Section 2.2.5.5. Micrometrics - should be micromeritics.

Response: It is corrected now.

 

- In terms of results and discussion, some of the results presented have not been discussed. For instance, the results in Table 1 and 2, the authors only mention the data without elaborating the reasons why it happened.

Response: Thanks for the suggestion. Here we have tried well to discuss most the results found during the experiments in the revised version. In Table 1, the detailed compositions of the developed formulations (SDs) were mentioned. The percentage yield (%) was mentioned in Table 1, the reason of variation in the yield value has been discussed in the revised version. The results mentioned in Table 2, haven discussed and included in the revised manuscript. The changes were highlighted with yellow texts.

 

- For FTIR & DSC, these results should be compared with the works of other and more discussed.

Response: Thank you for your valuable comment. As per the suggestion, the results of FTIR and DSC has been discussed in detail and compared with the previously reported available literatures. The changes were highlighted with yellow text in the revised manuscript.

 

- Figure 6 should be completed with annotations.

Response: As per the suggestion, Figure 6 has been completed with proper annotations. Updated Figure 6 has been incorporated in the revised manuscript.

 

 

Comments on the Quality of English Language

A moderate editing in English is required.

Response: Thank you very much for kind suggestions. We have made editing to improve the English language, now it is looking better than before.

Round 2

Reviewer 1 Report

No