Development and Evaluation of Ginkgo biloba L. Extract Loaded into Carboxymethyl Cellulose Sublingual Films
, Mindaugas Marksa 1, Laurynas Jarukas 1 and Liudas Ivanauskas 1Round 1
Reviewer 1 Report
The manuscript entitled “Development and evaluation of Ginkgo biloba L. extract loaded into carboxymethylcellulose sublingual films” presents the technology of obtaining sublingual films loaded with Ginkgo biloba extracts and the results of physicochemical characterization of films, besides the rate of release and the stability of bioactive compounds.
The introduction section covers all the background of the study and is clear presented, but please see above some comments on the English style used into the text.
The material and methods section contains all the information needed to understand the experimental methods used for this study.
The results section presents and discusses the obtained experimental data, showing that carboxymethylcellulose film containing the freeze-dried plant extracts can improve the dispersibility and dissolution rate of biological active flavonoids from Gingko Biloba.
Author Response
Response to the Editor and Reviewer’s comments on the manuscript
“Development and Evaluation of Gingko biloba L. Extract Loaded into Carboxymethyl cellulose Sublingual Films”
The authors would like to thank Reviewer for their comments and suggestions to improve the quality of the manuscript. Please find below our response to the remarks, the corresponding corrections of the manuscript have been made. Moreover, the stylistic corrections and additions as well as some new text were added on the basis of recommendations of reviewers.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript entitled “Development and evaluation of Ginkgo biloba L. extract loaded into carboxymethylcellulose sublingual films” deals with the evaluation of CMC based sublingual films with Ginkgo biloba L. extract in physicochemical evaluation by SEM and FTIR, mechanical properties and in vitro drug release for exploit and optimize the amount of GFD in sublingual films in order to make a positive impact on desirable features of a drug formulation, such as more rapid drug release, higher release yields and improvement of drug stability.
Overall, I see the work as excellent from a scientific point of view, with the formulations duly characterized by various methods and optimized in terms of components. Nevertheless, there are small errors that must be corrected to be published and many of them are grammatical and spelling errors:
Line19-20: “performed by SEM, FTIR. The mechanical properties and in vitro release of the prepared films were characterized…” change for “performed by SEM and FTIR. The…”
Line 23 GFD is in parentheses and I think it shouldn't be in, as well as in the legend of Table 4 (line 380) and in the conclusions (line 390).
Line 66-67: “methods of film manufacturing. Hot melt extrusion method is more often used to manufacture transdermal and transmucosal drug delivery systems, granules, sustained release tablets [22]”. change for “methods of film manufacturing. Hot melt extrusion method is more often used to manufacture transdermal and transmucosal drug delivery systems, granules and sustained release tablets [22]”.
Line 98-99:” Polyethylene glycol (PEG – MW1500) and glycerol were supplied by Sigma-Aldrich (Saint Louis, MO, United States); Arabic gum by Sigma-Aldrich (, Saint Louis, MO, United States).” change for “Polyethylene glycol (PEG – MW1500) and glycerol were supplied by Sigma-Aldrich (Saint Louis, MO, United States) and Arabic gum were supplied by Sigma-Aldrich (, Saint Louis, MO, United States).”
Line 107-108: “WNB7 (Memmert GmbH & Co. KG, Schwabach, Germany) at 95 °C for 1 hours. The prepared extract was filtered using vacuum filter.” change for “WNB7 (Memmert GmbH & Co. KG, Schwabach, Germany) at 95 °C for 1 hours. The prepared extract was filtered using a vacuum filter.”
Line 113 and 114 gum arabic must be changed for arabic gum.
Line 117: In the freeze-drying process should be added other parameters as freezing temperature, a sublimation pressure and a sublimation temperature.
Line 127-128: “and then kept for drying at 60 °C for 4 h, the RH 75%.” change for “and then kept for drying at 60 °C for 4 h, at RH of 75%.”
Line 164-165: “chromatogram obtained with the test solution; A2 – areas of the peak due to quercetin in the chromatogram obtained with the reference solution; p – percentage cont…“ change for “chromatogram obtained with the test solution; A2 – areas of the peak due to quercetin in the chromatogram obtained with the reference solution and p – percentage cont…“
Line 221: Authors should cite the ICH guidelines in the references and specify the stability ICH (number) consulted in the text.
Line 275 carboxymethyl cellulose should be abbreviated. Moreover in the title is written as carboxymethylcellulose. Revised this word in the text.
In Figure 2 FGD should be changed for GFD.
Line 322-323: “content of flavonoid glycosides was calculated using following formula, which is described in HPLC Conditions for…”change for “content of flavonoid glycosides was calculated using following formula, which is described in HPLC conditions for…”
Line 339: Tedesco [40] with authors change for Tedesco [40] and coauthors.
In FTIR analysis, the authors should change 1, 2 and 3 in Figure 4 for A, B, C to avoid misunderstandings for readers. Moreover spectrums change for spectra, and as a suggestion, they should always expose the peaks in order or ascending or descending in that paragraph. In legend of Figure 4 the end point is missing.
Finally, in line 370 separate ° from 2 in ± 2°C as in the following line.
Comments for author File: 
Comments.pdf
Author Response
Response to the Editor and Reviewer’s comments on the manuscript
“Development and Evaluation of Gingko biloba L. Extract Loaded into Carboxymethyl cellulose Sublingual Films”
The authors would like to thank Reviewer for their comments and suggestions to improve the quality of the manuscript. Please find below our response to the remarks, the corresponding corrections of the manuscript have been made. Moreover, the stylistic corrections and additions as well as some new text were added on the basis of recommendations of reviewers.
Comments and suggestions to authors
Reviewer 2:
The manuscript entitled “Development and evaluation of Ginkgo biloba L. extract loaded into carboxymethylcellulose sublingual films” deals with the evaluation of CMC based sublingual films with Ginkgo biloba L. extract in physicochemical evaluation by SEM and FTIR, mechanical properties and in vitro drug release for exploit and optimize the amount of GFD in sublingual films in order to make a positive impact on desirable features of a drug formulation, such as more rapid drug release, higher release yields and improvement of drug stability.
Overall, I see the work as excellent from a scientific point of view, with the formulations duly characterized by various methods and optimized in terms of components. Nevertheless, there are small errors that must be corrected to be published and many of them are grammatical and spelling errors:
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Line19-20: “performed by SEM, FTIR. The mechanical properties and in vitro release of the prepared films were characterized…” change for “performed by SEM and FTIR. The…” Response: the changes has been done according to the suggestion. |
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Line 23 GFD is in parentheses and I think it shouldn't be in, as well as in the legend of Table 4 (line 380) and in the conclusions (line 390). Response: the changes has been done according to the suggestion. |
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Line 66-67: “methods of film manufacturing. Hot melt extrusion method is more often used to manufacture transdermal and transmucosal drug delivery systems, granules, sustained release tablets [22]”. change for “methods of film manufacturing. Hot melt extrusion method is more often used to manufacture transdermal and transmucosal drug delivery systems, granules and sustained release tablets [22]”. Response: the changes has been done according to the suggestion. |
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Line 98-99:” Polyethylene glycol (PEG – MW1500) and glycerol were supplied by Sigma-Aldrich (Saint Louis, MO, United States); Arabic gum by Sigma-Aldrich (, Saint Louis, MO, United States).” change for “Polyethylene glycol (PEG – MW1500) and glycerol were supplied by Sigma-Aldrich (Saint Louis, MO, United States) and Arabic gum were supplied by Sigma-Aldrich (, Saint Louis, MO, United States).” Response: the changes has been done according to the suggestion. |
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Line 107-108: “WNB7 (Memmert GmbH & Co. KG, Schwabach, Germany) at 95 °C for 1 hours. The prepared extract was filtered using vacuum filter.” change for “WNB7 (Memmert GmbH & Co. KG, Schwabach, Germany) at 95 °C for 1 hours. The prepared extract was filtered using a vacuum filter.” Response: the changes has been done according to the suggestion. |
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Line 113 and 114 gum arabic must be changed for arabic gum. Response: the changes has been done according to the suggestion: gum arabic was changed to Arabic gum. |
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Line 117: In the freeze-drying process should be added other parameters as freezing temperature, a sublimation pressure and a sublimation temperature. Response: the other parameters of the freeze-drying process was added to the materials and methods section. Added information: The primary drying was carried out at 0.05 mbar for 12 h at a plate temperature of -50 °C. The secondary drying step was run for 12 h at 0 °C. |
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Line 127-128: “and then kept for drying at 60 °C for 4 h, the RH 75%.” change for “and then kept for drying at 60 °C for 4 h, at RH of 75%.” Response: the changes has been done according to the suggestion. |
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Line 164-165: “chromatogram obtained with the test solution; A2 – areas of the peak due to quercetin in the chromatogram obtained with the reference solution; p – percentage cont…“ change for “chromatogram obtained with the test solution; A2 – areas of the peak due to quercetin in the chromatogram obtained with the reference solution and p – percentage cont…“ Response: the changes has been done according to the suggestion. |
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Line 221: Authors should cite the ICH guidelines in the references and specify the stability ICH (number) consulted in the text. Response: the ICH number (ICH Q1A (R2)) added in materials and methods section and reference added to the reference list [No. 29]. |
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Line 275 carboxymethyl cellulose should be abbreviated. Moreover in the title is written as carboxymethylcellulose. Revised this word in the text. Response: in line 275 carboxymethyl cellulose was abbreviated to CMC. Also all manuscript was revised and in all cases carboxymethyl cellulose was abbreviated to CMC. |
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In Figure 2 FGD should be changed for GFD. Response: the changes has been done according to the suggestion. |
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Line 322-323: “content of flavonoid glycosides was calculated using following formula, which is described in HPLC Conditions for…”change for “content of flavonoid glycosides was calculated using following formula, which is described in HPLC conditions for…” Response: the changes has been done according to the suggestion. The sentance was rewritten: The percentage content of flavonoid glycosides was calculated using following formula, which is described in HPLC conditions for determination of flavonoids. |
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Line 339: Tedesco [40] with authors change for Tedesco [40] and coauthors. Response: the changes has been done according to the suggestion. |
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In FTIR analysis, the authors should change 1, 2 and 3 in Figure 4 for A, B, C to avoid misunderstandings for readers. Moreover spectrums change for spectra, and as a suggestion, they should always expose the peaks in order or ascending or descending in that paragraph. In legend of Figure 4 the end point is missing. Response: the changes has been done according to the suggestion. Numbers 1,2 and 3 were changed to letters A, B and C, spectrums to spectra and the end point was added. |
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Finally, in line 370 separate ° from 2 in ± 2°C as in the following line. Response: the changes has been done according to the suggestion. |
Author Response File: Author Response.docx
Reviewer 3 Report
This manuscript, titled “Development and evaluation of Ginkgo biloba L. extract loaded into carboxymethylcellulose sublingual films”, considers the preparation and characterization of CMC sublingual films loaded with Ginkgo biloba L. extract. Although the work is interesting and the presented results are quite relevant, I feel that the discussion is rather scarce. I encourage the authors to improve the quality of the manuscript according to the following comments/questions/doubts:
Abstract
- The Abstract that appears in the online submission system does not coincide with the one that appears in the manuscript.
- “due its chemical complexity …” – Replace by “due to its chemical complexity …”
What is the meaning of “chemical complexity”? High average molecular weight? Or something else? Slow dissolution in what? Water?
- “within films” – Films of what?
- “Physicochemical evaluation of films was performed by SEM, FTIR.” – “Physicochemical evaluation of films was performed by SEM and FTIR.”.
- “and in vitro release” – Release of what?
- “of 2% CMC” – Define “CMC”.
- “ (p < 0.05)” – What does it mean?
Introduction
- “The plant fascinates …” – Avoid this kind of sentences.
- “Solvent casting method was used in this study because of lesser requirements for applied active pharmaceutical ingredient, simple equipment required and because of the possibility to perform hydrous process.” – This sentence is a bit confusing. Please rewrite it.
- “The constituent polymers of sublingual films are chosen based on desired physicochemical properties of the product. Carboxymethylcellulose (CMC) is one of the commonly used polymers for preparation of sublingual films.” – Seems a bit incomplete. Extend it including references.
- “which is desirable drug features for patients” – “which are desirable drug features for patients”
- “elongation of the break” – Replace by “elongation at break”.
Materials and methods
- “2.1. Plant material” - More details are required.
- “with some modifications [23].” – Try to summarize said modifications.
- “The prepared dispersion was freeze-dried (LyoQuest Telstar, Germany) at -50°C overnight.” – Controlled time?
- “as a plasticizer according to preliminary experiments” – References?
- “The prepared solution 2 was used after 24 h to remove all the air bubbles.” – Clarify.
- “and then kept for drying at 60 °C for 4 h, the RH 75%.” – Where?
- “The samples were stored in a glass container maintained at a temperature of 30 °C and a relative humidity 130 of 60 ± 5%, until further analysis.” – Why?
- Table 1. Column “CMC 2 %, w/v (g)” - ?
- Replace “L” (referred to liters) by “l” throughout the manuscript.
- Please define “HPLC”.
- “Samples of the prepared films, free from air bubbles and any imperfections were held vertically between the two clamps of the instrument hold at 1cm apart, the lower clamp was fixed while the upper one was movable. Each film was pulled by the upper clamp at a rate of 50 mm/min. The force and elongation at the point of break were measured.” – Irrelevant information. You may simplify this part considerably.
- “Measurements were run for each film separately and average value was taken.” – How many samples?
- “percentage elongation” – Elongation at break?
- You may remove equations (2) and (3), as it well known how stress and strain are determined. As a matter of fact, as defined in equation (3), what you have is the strain and not the elongation (elongation = L – L0).
- “disintegration time was recorded (n=6)” – What is the meaning of “(n=6)”?
- SEM analysis – What about sample preparation?
Results and Discussion
- Table 2 – No need to include a lot of the information as footnote, as pretty much all the information already appears in the “Materials and methods” section (idem for Table 3). You may also remove “Results are expressed as mean ± standard deviation” from the title.
- “Furthermore, the increasing amount of GFD in matrix may have determined a more irregular structure of prepared films, which reflected in decrease of polymer matrix cohesion and, consequently, in tensile strength of the films.” – Can you demonstrate this?
- “Moreover, the Young’s modulus and tensile strength results may influence the glycerol, which was used as a plasticizer in all formulations.” – Rewrite.
- “with reduced brittleness” – Better “with enhanced ductility” or “with enhanced elongation at break”.
- You state that “For sublingual drug administration, flexible and strong films are preferable.” – Have you got any idea of typical/target values?
- “the average thickness values of films were between 0.06 and 0.12 mm.” – Why the big difference?
- “who reported that increasing concentration of carboxymethyl cellulose expanded film thickness, which could be happening due to entrapment of oil particles in film matrix pores.” – Unclear.
- Figure 1 caption – Reverse – start with the micrograph on the left. Why only FRG-15? What about the others?
- “Blank film (CMC-0) shows uniform structure. Moreover, the SEM images of prepared sublingual film show uniform surface morphology of FRG-15 sample with homogenous distribution of GFD and with no crystalline structures visible on SEM images.” – Unclear based on only two micrographs (obtained at different magnifications).
- Figure 2, y axis – “flavonoid”. Idem as Figure 1 – Why only FRG-15?
- “flavonoid glycosides was calculated using following formula, which is described in HPLC …” – Rewrite.
- Figure 3. “The obtained results showed that flavonoid glycosides, presented in FRG - 2, demonstrated 1.3 - 2.0 fold higher dispersion in solvent than GFD.” – Now FRG-2? Why not FRG-15?
- “The technological process might cause low bioavailability of active compounds in freeze-dried extract.” – Unclear.
- “High dissolution data influenced the choice of polymer as a drug carrier, which plays an important role in drug delivery systems.” - ?
- “FTIR spectrums” – “FTIR spectra”
- Figure 4 – Difficult to read. “sublingual film contained” – “sublingual film containing”
- “A comparison fig (1) with fig (2) and fig (3)” – Change these references, as you already have presented figures with the same numbering reference.
Conclusions
- “The formed films were free from air bubbles, cuttings or cracks.” – Images? “Cuttings”?
- “film formulation contained” – “film formulation containing”
Author Response
Response to the Editor and Reviewer’s comments on the manuscript
“Development and Evaluation of Gingko biloba L. Extract Loaded into Carboxymethyl cellulose Sublingual Films”
The authors would like to thank Reviewers for their comments and suggestions to improve the quality of the manuscript. Please find below our response to the remarks, the corresponding corrections of the manuscript have been made. Moreover, the stylistic corrections and additions as well as some new text were added on the basis of recommendations of reviewers.
Comments and suggestions to authors
Reviewer 3:
This manuscript, titled “Development and evaluation of Ginkgo biloba L. extract loaded into carboxymethylcellulose sublingual films”, considers the preparation and characterization of CMC sublingual films loaded with Ginkgo biloba L. extract. Although the work is interesting and the presented results are quite relevant, I feel that the discussion is rather scarce. I encourage the authors to improve the quality of the manuscript according to the following comments/questions/doubts:
Abstract
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The Abstract that appears in the online submission system does not coincide with the one that appears in the manuscript. Response: the mistake has been corrected. |
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“due its chemical complexity …” – Replace by “due to its chemical complexity …” Response: the mistake has been corrected. |
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What is the meaning of “chemical complexity”? High average molecular weight? Or something else? Slow dissolution in what? Water? Response: The main active compounds group in the Ginkgo biloba extract is flavonoid groups. According to literature the Ginkgo biloba extract contains about 22-27 % of flavonoid glycosides. The flavonoid glycosides are hydrophilic materials and has a high molecular weight and the dissolution in water is low. |
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“within films” – Films of what? Response: the mistake has been corrected and changed. |
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“Physicochemical evaluation of films was performed by SEM, FTIR.” – “Physicochemical evaluation of films was performed by SEM and FTIR.” Response: the mistake has been corrected. |
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“and in vitro release” – Release of what? Response: the sentence was changed to: The mechanical properties and in vitro release profile of flavonoid glycosides from the prepared films were characterized in the study. |
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“of 2% CMC” – Define “CMC”. Response: the CMC has been explained. |
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“(p < 0.05)” – What does it mean? Response: “(p < 0.05)” it shows the statistical differences between the samples. |
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Introduction |
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“The plant fascinates …” – Avoid this kind of sentences. Response: Authors agree with reviewer, that such kind of sentences do not fit for scientific publications and removed this sentence from the manuscript. |
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“Solvent casting method was used in this study because of lesser requirements for applied active pharmaceutical ingredient, simple equipment required and because of the possibility to perform hydrous process.” – This sentence is a bit confusing. Please rewrite it. Response: the sentence was changed to: Solvent casting method was used in this study due to its simple preparation method and it is suitable for the hydrophobic active ingredient incorporation into the hydrophilic carriers. |
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“The constituent polymers of sublingual films are chosen based on desired physicochemical properties of the product. Carboxymethylcellulose (CMC) is one of the commonly used polymers for preparation of sublingual films.” – Seems a bit incomplete. Extend it including references. Response: the explanation was extended and the references was added. Added information: The constituent polymers of sublingual films are chosen based on desired physicochemical properties of the product [23]. Moreover, polymer employed should be non-toxic, non-irritant and devoid of leachable impurities. It also should have good wetting and spreadability properties [23]. CMC is a cellulose derivative produced by the reaction of cellulose with sodium monochloracetate. CMC is one of the commonly used polymers for preparation of sublingual films. It can produce films with exellent clarity and with the ability to carry a wide range of active ingredients, which has been proven to be useful in the preparation optimal polymeric matrices [24]. |
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“which is desirable drug features for patients” – “which are desirable drug features for patients” Response: the changes has been done according to the suggestion. |
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“elongation of the break” – Replace by “elongation at break”. Response: “elongation of the break” it was replaced to “elongation at break”. |
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Materials and methods |
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“2.1. Plant material” - More details are required. Response: Missing information was added. Added information was: Samples were collected during the stages of leaf aging. The samples were collected from branches located at the height of 1-3 m from the ground. During each sampling, about 40 leaves were collected from different parts of the crown of Ginkgo biloba. To obtain a representative Ginkgo biloba leaf sample, leaves collected from different trees were mixed together into a single combined sample. Ginkgo biloba leaves were dried at room tempeture (25 °C ± 2). The dried raw material was packed into paper bags and was stored in a sun-protected dry environment at room temperature and at 60 ± 5% relative humidity until the analysis. Prior to the analysis, the air-dried raw material was ground, and the wastage of Ginkgo biloba leaves was evaluated. |
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“with some modifications [23].” – Try to summarize said modifications. Response: Authors noticed the mistake in this sentence with reference. They changed the old reference to new one, and there left no explain what modifications were made, because extraction procedure was made according to Ding and coauthors [25]. |
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“The prepared dispersion was freeze-dried (LyoQuest Telstar, Germany) at -50°C overnight.” – Controlled time? Response: the mistake has been corrected and changed to 24 hours. |
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“as a plasticizer according to preliminary experiments” – References? Response: the sentence was changed to: The CMC was used as film-forming polymers and glycerol was used as a plasticizer [22]. |
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“The prepared solution 2 was used after 24 h to remove all the air bubbles.” Clarify. Response: The prepared solution 2 was kept in the fridge (15 ± 0.5 °C) for 24 h to remove all the air bubbles from the sample. |
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“and then kept for drying at 60 °C for 4 h, the RH 75%.” – Where? Response: the mistake has been corrected: kept in the oven for drying at 60 ± 0.5 °C for 4 h, the RH 75 ± 0.5 %. |
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“The samples were stored in a glass container maintained at a temperature of 30 °C and a relative humidity 130 of 60 ± 5%, until further analysis.” – Why? Response: to avoid instability of the prepared films it was kept in a glass container. |
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Table 1. Column “CMC 2 %, w/v (g)” -? Response: the mistake has been corrected and the explanation was added above the table. |
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Replace “L” (referred to liters) by “l” throughout the manuscript. Response: “L” was changed by “l” throughout the manuscript. |
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Please define “HPLC”. Response: HPLC was defined. |
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“Samples of the prepared films, free from air bubbles and any imperfections were held vertically between the two clamps of the instrument hold at 1cm apart, the lower clamp was fixed while the upper one was movable. Each film was pulled by the upper clamp at a rate of 50 mm/min. The force and elongation at the point of break were measured.” – Irrelevant information. You may simplify this part considerably. Response: the text was simplified according to the suggestions. |
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“Measurements were run for each film separately and average value was taken.” – How many samples? Response: Measurement was done in triplicates and the average value was taken. |
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“percentage elongation” – Elongation at break? Response: the mistake has been corrected. |
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You may remove equations (2) and (3), as it well known how stress and strain are determined. As a matter of fact, as defined in equation (3), what you have is the strain and not the elongation (elongation = L – L0). Response: the equations was removed according to the suggestions. Where L0 is the original distance between the two grips of the tensometer and L is the distance between the two grips at the moment of film rupture. |
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“disintegration time was recorded (n=6)” – What is the meaning of “(n=6)”? Response: six replications were made for each sample. |
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SEM analysis – What about sample preparation? Response: the sample was directly used for SEM analysis, because the used apparatus doesn’t require any preparation. |
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Results and Discussion |
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Table 2 – No need to include a lot of the information as footnote, as pretty much all the information already appears in the “Materials and methods” section (idem for Table 3). You may also remove “Results are expressed as mean ± standard deviation” from the title. Response: the changes have been done according to the suggestions and the information was removed in table 2 and table 3. |
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“Furthermore, the increasing amount of GFD in matrix may have determined a more irregular structure of prepared films, which reflected in decrease of polymer matrix cohesion and, consequently, in tensile strength of the films.” – Can you demonstrate this? Response: the sentence was deleted because of lack relative information about the topic. |
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“Moreover, the Young’s modulus and tensile strength results may influence the glycerol, which was used as a plasticizer in all formulations.” – Rewrite. Response: sentence was rewritten: Moreover, the glycerol which was used as a plasticizer may influenced the Young’s modulus and tensile strength results. |
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“with reduced brittleness” – Better “with enhanced ductility” or “with enhanced elongation at break”. Response: the term “with reduced brittleness” was changed to “with enhanced ductility”. |
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You state that “For sublingual drug administration, flexible and strong films are preferable.” – Have you got any idea of typical/target values? Response: the typical/target dose 40 mg/3 times a day. |
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“the average thickness values of films were between 0.06 and 0.12 mm.” – Why the big difference? Response: the increasing GFD concentration raised thickness values. |
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“who reported that increasing concentration of carboxymethyl cellulose expanded film thickness, which could be happening due to entrapment of oil particles in film matrix pores.” – Unclear. Response: the sentence was changed: Our findings correspond with results of Dashipour et. al. It was reported in the manuscript that increasing concentration of carboxymethyl cellulose expanded film thickness, which could be happening due to entrapment of oil particles in film matrix pores [34]. |
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Figure 1 caption – Reverse – start with the micrograph on the left. Why only FRG-15? What about the others? Response: SEM analysis was done only for the sample coded FRG – 15, since it showed higher elongation and tensile strength, and faster disintegration time, which are important physicochemical properties for production. |
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“Blank film (CMC-0) shows uniform structure. Moreover, the SEM images of prepared sublingual film show uniform surface morphology of FRG-15 sample with homogenous distribution of GFD and with no crystalline structures visible on SEM images.” – Unclear based on only two micrographs (obtained at different magnifications). Response: Thank you very much for the comment but during extreme situation in Lithuania we won’t be able to do more SEM photos. The obtained micrographs were done earlier and now in this extreme time we won’t be able to continue this analysis. In our opinion, the two different magnifications show two different samples one is blank CMC film sample, second photo shows the FRG-15 formulation with incorporated extract into the film formulation. The different magnifications also it is important, because in the blank and in the FRG-15 samples we used the amount of CMC solution and the same amount of glycerol. We discussed only about the surface morphology, which is an important parameter for sublingual film formulation. The aim of this analysis is to prepare the homogeneous systems. |
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Figure 2, y axis – “flavonoid”. Idem as Figure 1 – Why only FRG-15? Response: the mistake with word - flavonoid was corrected. Release assay was performed only for the sample coded FRG – 15 (the size of the film was 2 × 2 cm and the mass of one film was 0.95 g), since it showed higher elongation and tensile strength, and faster disintegration time, which are important physicochemical properties for production and marketing of this dosage form (Figure 2). |
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“flavonoid glycosides was calculated using following formula, which is described in HPLC …” – Rewrite. Response: the sentence was rewritten: The percentage content of flavonoid glycosides was calculated using following formula, which is described in HPLC conditions for determination of flavonoids. |
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Figure 3. “The obtained results showed that flavonoid glycosides, presented in FRG - 2, demonstrated 1.3 - 2.0 fold higher dispersion in solvent than GFD.” – Now FRG-2? Why not FRG-15? Response: the mistake has been corrected. |
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“The technological process might cause low bioavailability of active compounds in freeze-dried extract.” – Unclear. Response: This issue could be explained that the technological process such as freeze-drying influenced low bioavailability of flavonoid glycosides in the formulation. |
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“High dissolution data influenced the choice of polymer as a drug carrier, which plays an important role in drug delivery systems.” - ? Response: the sentences were deleted. |
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“FTIR spectrums” – “FTIR spectra” Response: “FTIR spectrums” was changed to “FTIR spectra”. |
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Figure 4 – Difficult to read. “sublingual film contained” – “sublingual film containing” Response: “sublingual film contained” was changed to “sublingual film containing”. |
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“A comparison fig (1) with fig (2) and fig (3)” – Change these references, as you already have presented figures with the same numbering reference. Response: the changes has been done according to the suggestion. Numbers 1,2 and 3 were changed to letters A, B and C. |
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Conclusions |
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“The formed films were free from air bubbles, cuttings or cracks.” – Images? “Cuttings”? Response: the mistake has been corrected and information was deleted. |
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“film formulation contained” – “film formulation containing” Response: the mistake has been corrected and changed according to requirements. |
Author Response File: Author Response.docx
Round 2
Reviewer 3 Report
I would like to thank the authors for taking into account and individually addressing all my comments/questions/doubts. I think that the manuscript has improved significantly and is now fit to be pusblished in Applied Sciences.
