Development of Cyclodextrin-Based Mono and Dual Encapsulated Powders by Spray Drying for Successful Preservation of Everlasting Flower Extract

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors Ćujić-Nikolić et al. developed mono and dual encapsulated powders for preservation of everlasting flower extract based on cyclodextrins. The spray drying procedure was applied for powders preparation. This study ("Development of cyclodextrin-based mono and dual encapsulated powders by spray drying for successful preservation of everlasting flower extract") is a well detailed thorough work.

The authors stated the highest encapsulation efficiency with HP-β-cyclodextrin. The conventional carriers such as maltodextrin and whey protein were used in the mixtures with cyclodextrins. The highest yields were achieved in combinations of cyclodextrins and whey protein.

The authors proposed the enhanced functional properties of Helichrysum plicatum extract.

 

The Introduction of the study provides sufficient, the methods are well-described. The authors provided an exhaustive characterization of the obtained formulations by a great number of methods. The reference list contains a sufficient number of recent studies.

The manuscript is well written and easy to follow.

The novelty of the study is clear since there are no studies on the feasibility of the microencapsulation process by spray drying of any Helichrysum species.

 

The topic is relevant to the aim and scope of the Pharmaceutics.

Overall, this manuscript meets the standard for acceptance after addressing the minor comments below:

 

1) Lines 80-81

" Including the internal cavity… " This sentence needs references since it is not a common case when a slow release from CD formulations takes place.

2) Line 84

Some words accompanied by the appropriate references concerning the toxic action and the optimal amount of CD in drug formulations (ex. DOI: 10.1177/0192623307310945 or DOI:10.1155/2015/198268) should be also provided.

3) Lines 90-91

According to the literature the authors stated "……WP is much more effective in encapsulating polyphenolic compounds compared to maltodextrin" From this the decision of using maltodextrin seems surprising. Explain, please.

4) Lines 429-434

The issue of pH is unclear. Please, indicate the main factors determining the pH in different formulations.

5) Line 540     3.2.4. Spray-dried powders morphology

Please, underline more clearly the advantage of combinations of HP-beta-cyclodextrin and whey protein from the point of powder morphology.

Author Response

Dear Dr.,

Thank you very much for considering the Manuscript entitled “Development of cyclodextrin-based mono and dual encapsulated powders by spray drying for successful preservation of everlasting flower extract” for publication in Pharmaceutics. In Revision, we have taken all of the Reviewer's comments into account, and we hope that we have responded satisfactorily to the remarks. Changes in the text are marked with yellow color. The authors are hoping that the text is now in appropriate form. 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript developed a microencapsulation of everlasting (H. plicatum) flower extract by spray drying method. For wall materials, i.e. β- cyclodextrin, 2-hydroxypropyl-β-cyclodextrin, maltodextrin and whey protein, alone and their combinations were compared. There are some issues that needed to be clarified.

 

1. Spray drying is a mature pharmaceutical technology, and maltodextrin, whey protein, β- cyclodextrin, and 2-hydroxypropyl-β-cyclodextrin are all commonly used wall materials for spray drying. Though there are no studies on the feasibility of the microencapsulation process by spray drying of any Helichrysum species, it has been used for many other plants, which weakened the innovation of the research. The comparison between this manuscript and published studies had better be added to highlight the innovation of the study.

2. The study aimed to develop encapsulation systems to maintain the limited stability of everlasting (Helichrysum plicatum) flower extract polyphenols, as shown in abstract. However, there was no stability study to verify whether this aim was achieved.

3. The manuscript evaluated the extract-carrier interactions and thermal stability using FTIR and DSC，respectively, but it could not verify successful entrapment of SHE into carriers to form microencapsules.

4. Figure 4 did not show an obvious difference between pure SHE and carrier-extract complexes. It seemed that all samples were good and intact spheres.

5. When analyzing the DSC results, the groups having significant differences according to table 3 should be identified and the reasons should be explained clearly.

4. Others

(1) In the temperature column of Table 3, all groups were marked with the letter b, which meant there was no significant difference between any two groups. Why were some groups still marked with the letter a?

(2)What are microbeads in Table 4? This word was not found elsewhere in the manuscript.

(3) Should EE be encapsulation efficiency or drying efficiency in Table 4?

(4) HPBCD should be HP-β- CD.

(5)’ the extract-carrier interactions and thermal stability were by DSC and FTIR analysis’ should be ‘the extract-carrier interactions and thermal stability were by FTIR and DSC analysis’.

Comments on the Quality of English Language

Some sentences are diffulult to understand, such as 

Each biopolymer was dissolved separately in a previously prepared LHE and the combination of MD and WP with previously mentioned CDs.

 

Author Response

Dear Dr.,

Thank you very much for considering the Manuscript entitled “Development of cyclodextrin-based mono and dual encapsulated powders by spray drying for successful preservation of everlasting flower extract” for publication in Pharmaceutics. In Revision, we have taken all of the Reviewer’s comments into account, and we hope that we have responded satisfactorily to the remarks. Changes in the text are marked with yellow color. The authors are hoping that the text is now in appropriate form. Here are our answers to specific points:

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors The manuscript has been revised according previous suggestions.