Imidazole Antifungals Against Fungal Pathogens: Resistance Mechanisms and Emerging Delivery Strategies

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The review article focusing on the resistance mechanism and emerging delivery strategies of imidazole antifungal agents is interesting and matches the scope of the journal. A few sections of the manuscript needs to be improved for clarity and additional information. Authors are requested to address the below comments:

1. Can authors please rewrite the abstract for better flow and content and whole context of the review.
2. In the introduction, authors are suggested make a detailed note on the limitations of existing formulations and any challenges associated with the delivery of imidazole compounds
3. Within in the literature search, what was the search criteria for year of publications?
4. Within the structure activity relationship, can authors please make a detailed notes on the chemical groups and associated advantages and limitations, can the groups associated with limitations can be replaced with other groups without affecting the clinical pharmacology.
5. Mechanism of action needs to be improved with more detailed information and proper flow of the content
6. Are all the medications listed in Table 1 focused on topical delivery? If so, please make it clear within Table legend.
7. Within topical imidazole section, please make a note on the recent innovation platforms and advancements
8. Is ketoconazole the only oral antifungal medicine available in the market?
9. In table 2, please include a column for innovation and for each of the formulation type please make a note on the achievement compared with the traditional formulations
10. Please make a figure or tablet to present the pharmacokinetics and pharmacodynamics of imidazole antifungals
11. Please concise the conclusion section and focus on the major finding and gaps in the research
12. The entire manuscript needs to be reviewed and corrected for English

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

Reviewer comments

1. Can authors please rewrite the abstract for better flow and content and whole context of the review.

Response:

We appreciate this suggestion. The abstract has been fully rewritten to improve clarity, coherence, and critical depth. We streamlined the narrative to follow a clear progression from clinical need to mechanistic basis, resistance challenges, and translational solutions. Redundancies and overly long sentences were removed, and the central theme, linking resistance biology with biopharmaceutical and drug delivery constraints has been made explicit. The revised abstract now provides a more focused and integrated overview aligned with the scope of the review.

"Revisions as per the reviewer’s suggestions are highlighted on page 2.

2. In the introduction, authors are suggested make a detailed note on the limitations of existing formulations and any challenges associated with the delivery of imidazole compounds

Response:

We thank the reviewer for this important suggestion. The Introduction has been revised to provide a more detailed and structured discussion of the limitations of existing imidazole formulations and the associated drug delivery challenges. Specifically, we have expanded the section to address key biopharmaceutical constraints, including poor aqueous solubility, high lipophilicity, limited penetration through keratinized and mucosal barriers, short residence time at the site of application, and variability in local drug exposure. We also incorporated discussion on formulation-related limitations such as rapid clearance, inconsistent release profiles, and subtherapeutic drug concentrations in biofilm-associated infections. These additions strengthen the rationale for advanced delivery strategies and better align the Introduction with the central theme of the review.

"Revisions as per the reviewer’s suggestions are highlighted on page 3.

3. Within in the literature search, what was the search criteria for year of publications?

Response:

We thank the reviewer for highlighting this omission. The Methods section has been revised to clearly specify the publication timeframe used in the literature search. We defined a primary inclusion window focused on recent studies to ensure relevance, while also incorporating seminal earlier reports where necessary to provide historical and mechanistic context. This clarification has now been explicitly stated in the revised manuscript.

"Revisions as per the reviewer’s suggestions are highlighted on pages 4,5.

4. Within the structure activity relationship, can authors please make a detailed notes on the chemical groups and associated advantages and limitations, can the groups associated with limitations can be replaced with other groups without affecting the clinical pharmacology.

Response:

We thank the reviewer for this insightful comment. The Structure–Activity Relationship (SAR) section has been substantially expanded to provide a more detailed and critical analysis of key chemical groups in imidazole antifungals. Specifically, we now discuss how distinct functional moieties (e.g., halogenated aryl groups, lipophilic side chains, linker regions, and heteroaromatic substitutions) influence antifungal potency, selectivity, solubility, and pharmacokinetic behavior. In addition, we outline the limitations associated with these groups, including increased lipophilicity, reduced aqueous solubility, off-target interactions, and metabolic instability. Importantly, we have incorporated a discussion on rational substitution strategies, highlighting how these limitations can be mitigated through chemical modification (e.g., polarity tuning, bioisosteric replacement, and linker optimization) without compromising clinical efficacy. These revisions provide a more mechanistic and translational perspective on SAR in imidazole antifungals.

"Revisions as per the reviewer’s suggestions are highlighted on page 6.

5. Mechanism of action needs to be improved with more detailed information and proper flow of the content.

Response:

We thank the reviewer for this valuable suggestion. The Mechanism of Action section has been substantially revised to improve both depth and logical flow. Specifically, the section has been reorganized into clearly defined subsections to enhance readability and mechanistic clarity. We have expanded the molecular description of CYP51 inhibition, including detailed explanation of heme coordination and its structural basis, followed by a more comprehensive discussion of downstream effects such as ergosterol depletion, accumulation of aberrant sterol intermediates, and consequent membrane destabilization.

In addition, we have strengthened the pharmacodynamic perspective by incorporating concentration-dependent antifungal activity (fungistatic versus fungicidal effects) and the role of tissue-level drug exposure in modulating therapeutic outcomes. The revised section now also includes an integrated discussion of how microenvironmental factors influence the mechanistic cascade, thereby improving the overall scientific coherence of the section.

Overall, these revisions significantly improve the depth, structure, and readability of the mechanism of action section.

"Revisions as per the reviewer’s suggestions are highlighted on pages 8,9,10.

6. Are all the medications listed in Table 1 focused on topical delivery? If so, please make it clear within Table legend.

Response:

We thank the reviewer for this important observation. Table 1 primarily summarizes imidazole antifungal agents used in topical and mucosal applications, as the focus of this section is on localized delivery and clinical use in superficial infections. To improve clarity, we have revised the table legend to explicitly state that the listed medications are predominantly intended for topical or mucosal administration, with emphasis on their formulation types and clinical applications in superficial fungal infections. This modification ensures that the scope and context of the table are clearly communicated to the reader.

"Revisions as per the reviewer’s suggestions are highlighted on page 12.

7. Within topical imidazole section, please make a note on the recent innovation platforms and advancements

Responses:

We thank the reviewer for this valuable suggestion. The Topical Imidazoles section has been revised to include recent advances in formulation and delivery platforms. Specifically, we have incorporated a concise discussion on lipid-based carriers, vesicular systems, nanoemulsions, and polymeric nanogels, along with their roles in enhancing drug penetration, retention, and controlled release. The revised text also briefly highlights emerging hybrid approaches for difficult-to-treat infections. These additions improve the translational relevance of the section and align the discussion with current formulation strategies.

"Revisions as per the reviewer’s suggestions are highlighted on page 11.

8. Is ketoconazole the only oral antifungal medicine available in the market?

Response:

We thank the reviewer for this important clarification. We have revised Section 5.2 (Systemic Imidazoles) to clearly indicate that ketoconazole is not the only oral antifungal agent. The text now explicitly states that other classes of oral antifungals, including triazoles (e.g., fluconazole and itraconazole) and the allylamine terbinafine, are more widely used in clinical practice due to their improved safety profiles and pharmacokinetic properties. We have also clarified that the use of oral ketoconazole has become limited due to safety concerns such as hepatotoxicity and drug–drug interactions. These revisions ensure accurate representation of current clinical practice and eliminate any potential ambiguity.

"Revisions as per the reviewer’s suggestions are highlighted on pages 14.

9. In table 2, please include a column for innovation and for each of the formulation type please make a note on the achievement compared with the traditional formulations

Response:

Thank you for this valuable suggestion. Table 2 has been comprehensively revised to improve clarity and critical interpretation. A new column titled “Innovation” has been added to explicitly highlight the formulation design principles and technological novelty of each delivery system.

Additionally, the previous column describing advancement has been refined and renamed as “Achievement vs. Conventional Formulations”, where the comparative advantages over traditional topical dosage forms (e.g., creams and ointments) are now clearly and consistently articulated. These revisions collectively enhance the scientific rigor and translational relevance of the table.

"Revisions as per the reviewer’s suggestions are highlighted on pages 15 to 26.

10. Please make a figure or tablet to present the pharmacokinetics and pharmacodynamics of imidazole antifungals

Response:

We thank the reviewer for this valuable suggestion. In response, we have included a new figure 4. summarizing the key pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of imidazole antifungals. The figure provides a structured comparison of parameters such as absorption, distribution, metabolism, elimination, and concentration-dependent antifungal activity, with distinctions between topical and systemic exposure. This addition improves clarity and provides a concise, integrated overview of PK/PD properties relevant to clinical performance.

"Revisions as per the reviewer’s suggestions are highlighted on pags 33.

11. Please concise the conclusion section and focus on the major finding and gaps in the research

Response:

We thank the reviewer for this helpful suggestion. The conclusion section has been revised to improve conciseness and focus. Specifically, we have streamlined the text to emphasize the major findings of the review, including the mechanism-driven activity of imidazole antifungals, the importance of pharmacokinetic exposure and formulation strategies, and the current preference for topical delivery. In addition, we have clearly highlighted key research gaps, particularly in optimizing drug delivery, overcoming biological barriers, and improving clinical translation. These revisions enhance clarity, reduce redundancy, and align the conclusion with the overall scope and contributions of the manuscript.

"Revisions as per the reviewer’s suggestions are highlighted on page 46.

12. The entire manuscript needs to be reviewed and corrected for English

Response:

We thank the reviewer for this important observation. The entire manuscript has been carefully revised to improve language clarity, grammar, and overall readability. We have corrected grammatical errors, improved sentence structure, removed redundancies, and ensured consistency in scientific terminology and style throughout the text. In addition, the manuscript has been edited to achieve a more coherent and professional academic tone in line with journal standards. All changes have been incorporated and are reflected in the revised version.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript submitted by Saini et al. provides a comprehensive review of imidazole antifungal agents, covering their chemistry, mechanism of action, clinical applications, resistance mechanisms (CYP51 mutations, efflux pumps, biofilms), and advanced delivery strategies (lipid nanoparticles, nanoemulsions, ionic liquids, etc.) aimed at overcoming bioavailability limitations and resistance. In general, the manuscript contains a lot of information, informative summarizing tables and nice illustrtaions. Nevertheless, the revision is required to add some clarity and strenghth some sections.

1. Section 3, dedicated to the chemistry of imidazoles, contains only a verbal description and does not include any chemical structures. It would be advisable to supplement this section with the actual chemistry.
2. The review lacks a critical assessment of the comparative efficacy of different nanocarrier systems against each other. Which of them have actually reached clinical trials, and which have remained at the level of laboratory development?
3. Some figures (e.g., Fig. 6) contain small, illegible text that needs to be improved.
4. Figure 5 is mentioned in the text, but no explanation or description of this figure is provided in the text.
5. The page numbering in the manuscript should be made consecutive, as there are currently problems with it in the current version.

Author Response

Reviewer’s comments

1. Section 3, dedicated to the chemistry of imidazoles, contains only a verbal description and does not include any chemical structures. It would be advisable to supplement this section with the actual chemistry.

Responses:

We thank the reviewer for this insightful comment. The Structure–Activity Relationship (SAR) section has been substantially expanded to provide a more detailed and critical analysis of key chemical groups in imidazole antifungals. Specifically, we now discuss how distinct functional moieties (e.g., halogenated aryl groups, lipophilic side chains, linker regions, and heteroaromatic substitutions) influence antifungal potency, selectivity, solubility, and pharmacokinetic behavior. In addition, we outline the limitations associated with these groups including increased lipophilicity, reduced aqueous solubility, off-target interactions, and metabolic instability. Importantly, we have incorporated a discussion on rational substitution strategies, highlighting how these limitations can be mitigated through chemical modification (e.g., polarity tuning, bioisosteric replacement, and linker optimization) without compromising clinical efficacy. These revisions provide a more mechanistic and translational perspective on chemistry of imidazole antifungals. We have shifted the position of Figure 3 (i.e. Structures of Different Imidazole derivative) in the chemistry section and now it will be read as Figure 2.

"Revisions as per the reviewer’s suggestions are highlighted on pages 6,7.

2. The review lacks a critical assessment of the comparative efficacy of different nanocarrier systems against each other. Which of them have actually reached clinical trials, and which have remained at the level of laboratory development?

Response:

We thank the reviewer for this insightful comment. In response, we have revised the nanocarrier discussion in Section 5.1 to include a critical comparison of different delivery systems. Additionally, a new Table 3 has been introduced to summarize the comparative performance, key limitations, and translational status of these platforms. This table distinguishes systems with emerging clinical relevance from those that remain at the preclinical stage, thereby addressing the gap between formulation innovation and clinical translation.

“Revisions as per the reviewer’s suggestions are highlighted on page 27.

3. Some figures (e.g., Fig. 6) contain small, illegible text that needs to be improved.

Response:

Thank you for highlighting this issue. The resolution and readability of all figures, including Fig. 6, have been carefully improved. Font sizes, labels, and annotations have been enlarged and standardized to ensure clarity and legibility at publication scale. High-resolution versions of the revised figures have been provided, and formatting has been optimized in accordance with the journal’s guidelines.

4. Figure 5 is mentioned in the text, but no explanation or description of this figure is provided in the text.

Response:

We thank the reviewer for this insightful comment.  We have highlighted the figure cited in the text.

“Revisions as per the reviewer’s suggestions are highlighted on page 36.

5. The page numbering in the manuscript should be made consecutive, as there are currently problems with it in the current version.

Response:

Thank you for pointing this out. The page numbering issue has been corrected, and the manuscript has been carefully revised to ensure consecutive and consistency throughout the manuscript. The updated version now follows the journal’s formatting requirements.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

All comments are well addressed with proper justification and supporting literature. The revised version of the manuscript can be accepted for publication.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have made substantial revisions to the manuscript. Now the manuscript looks stronger and is suitable for publication in its present form.