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Associate Professor Yousuf Mohammed
Associate Professor

Yousuf Mohammed

Email: 
Phone: 
+61 7 344 37485
Mobile: 
0433853534

Overview

Background

Dr Yousuf Mohammed completed his PhD in pharmaceutics and skin drug delivery under the guidance of Associate prof Heather Benson, Prof Michael Roberts and Associate prof Tarl Prow. He has been working within the field of skin delivery at the Therapeutics Research Centre, University of Queensland - School of Medicine since 2012. His current research includes managing a five-year (2018-2023) US FDA funded project titled Bioequivalence of Topical products: Elucidating the Thermodynamic and Functional Characteristics of Compositionally Different Topical Formulations as a Principle Investigator and managing the five-year project (2014-2019) Characterization of Critical Quality Attributes for Semisolid Topical Drug Products as a Co-investigator. These projects aims to improve current regulatory guidelines for topical and transdermal semisolid products. Over the last 6 years, his work has been focused on skin penetration and skin toxicology of drugs and xenobiotics including nanoparticulate materials.

Availability

Associate Professor Yousuf Mohammed is:
Available for supervision
Media expert

Qualifications

  • Masters (Coursework), Curtin University of Technology
  • Doctor of Philosophy, Curtin University of Technology

Research interests

  • Bioequivalence of Topical products: Elucidating the sensorial and functional characteristics of Topical Formulations

    In addition to the defined therapeutic effect caused by an active drug in a product, there is also a placebo and, potentially, a nocebo effect associated with those products. In topical products, these latter effects may account from 30% to 50% of the overall response for some products. They may also explain why some topical products with apparently identical bioavailability are associated with different patient outcomes. This application seeks to address the question of when do subtle excipient and manufacturing changes in a topical product cause a sensorial sensation by subjects that the “feel” of a product has changed either before and/or after it is applied to human skin. A second question is whether the “feel” of a product both before and after application can be quantified by instrumental rheology, tribology and texture analysis methods and whether these, in turn, can be related to the reported sensorial behaviour. We will manufacture topical formulations that systematically vary in Q1, Q2, and/or Q3 attributes and have large and borderline perceptive differences. We will then characterized these products using a range of rheology, tribology and texture analysis methods. In parallel, these products will be evaluated by perceptive testing focus groups, with controls, of their sensorial characterisation of the ‘feel’ of the products. We will then relate these sensorial findings with the variations in formulation nature, composition and manufacture, and their resulting instrumental test results. Our goals are, firstly, to understand the relationships between product nature, instrumental findings and sensorial analyses and, secondly, to derive criteria for instrument tests that indicates what product composition subjects suggest do not differ, uncertain if they differ and do differ in their sensorial behaviour. It is hoped that we can define the simplest, robust test that accurately and robustly is in line with sensory perceptions. A range of statistical methods, including (potentially) sophisticated, machine learning and deep learning tools will then be used to model the most appropriate instrumental analysis that can, with reasonable confidence predict perceptive attributes. A key outcome is a potential regulatory guideline advocating that generic products should exhibit similar sensorial behaviour as a reference listed drug product, giving boundaries in rheology, tribology and texture analysis as defined by Q1, Q2 and Q3 differences when that sensorial behaviour between topical products is likely to be different.

  • Bioequivalence of Topical products: Elucidating the Thermodynamic and Functional Characteristics of Compositionally Different Topical Formulations

    The general requirements for generics to be considered are that the product is off-patent, contains an active ingredient in a previously approved medicine and is shown to be bioequivalent to that previously approved medicine. The fundamental forces governing the effects of topical drugs applied to the skin can be summed up in three distinct dimensions. 1. The interaction of the active pharmaceutical ingredient (API) with the excipients (formulation factors, solubility), 2. API with the skin (thermodynamic and pharmacodynamic activity) and 3. Excipient with the skin (penetration enhancement, diffusivity, irritancy). A thoughtful appreciation followed by a thorough understanding and then careful deliberations can help mitigate a number of failure modes that can arise from these three dimensions and result in disapproval of generic drug applications. However, there is an elusive fourth dimension, the psychorheology or the sensory/perceptive judgement of the rheological properties (and other organoleptic properties) that dictates the end user/consumers final acceptance of the product. Through this project we aim to develop meaningful risk mitigating methods and their scientific basis. These will encompass considering product behaviour during various stages of development/manufacturing, all the way to looking at the metamorphosing product as it is being applied to the treatment site on the skin. The development of generic topical products has been hampered by factors such as expensive clinical trials for BE assessment and application costs which get blown out due to the case by case assessment of applications. A burdensome application package is generally needed that wastes valuable resources and time on both sides of the coin. This project will ensure the much needed theoretical and practical framework that can enable a thorough yet efficient assessment of topical generic product applications.

  • Characterization of Critical Quality Attributes for Semisolid Topical Drug Products

    This US FDA funded project aims to understand the formulation-drug-skin interactions. Certain physicochemical attributes of a pharmaceutical product can be deemed as Critical Quality Attributes based on their influence of the product performance. This 5 year project goes into 16 different quality attributes and tests for their role in the performance of topical products using 22 different tests and numerous instruments and methods.

  • Toxicology of topically applied nanoparticles

    The safety of nanoparticles used in sunscreens has been a controversial international issue in recent years, in part because previous animal exposure studies generally found much higher skin absorption of zinc from dermal application of ZnO sunscreens than human studies. Our group’s work for the last several years has challenged these false alarms and through evidence based volunteer studies, provided the vital confidence boosting evidence for safe use of sunscreens. This is particularly relevant as the typical exposure to dangerous UV radiations has been on the rise.

Research impacts

Dr Yousuf Mohammed completed his PhD in pharmaceutics and skin drug delivery under the guidance of Associate prof Heather Benson, Prof Michael Roberts and Associate prof Tarl Prow. He has been working within the field of skin delivery at the Therapeutics Research Centre, University of Queensland - School of Medicine since 2012. His current research includes managing a five-year (2018-2023) US FDA funded project titled Bioequivalence of Topical products: Elucidating the Thermodynamic and Functional Characteristics of Compositionally Different Topical Formulations as a Principle Investigator and managing a four-year (2019-2023) US FDA funded project titled Bioequivalence of Topical products: Elucidating the sensorial and functional characteristics of Topical Formulations as a Principle Investigator. He is also currently managing the five-year project (2014-2019) Characterization of Critical Quality Attributes for Semisolid Topical Drug Products as a Co-investigator. These projects aims to improve current regulatory guidelines for topical and transdermal semisolid products in its second year of No Cost Extension. Over the last 6 years, his work has been focused on skin penetration and skin toxicology of drugs and xenobiotics including nanoparticulate materials.

Working on the US FDA project over the last two years has given an opportunity to showcase real world translational research. The work Yousuf and team has done has led to FDA guidance for Acyclovir creams which highlight the novel methods developed as a part of the work carried out locally in Brisbane in between TRI and other labs in the St Lucia campus.

Role of dispensers on physicochemical properties of the cream when dispensed. Difference in product performance upon dispensing from different dispensers was first identified and reported by our group and the change in cream product guidance based on this work is one of the biggest achievements. Our work over the last couple of years and specifically in the current year (July 2016- June 2017) has also identified skin and drug properties that determine product performance. Of special mention is our work on testing IVPT performance with different doses, different skin membrane types and different sampling protocols and different study durations. This a part of grant’s Aim 3 where we proposed to develop ideal IVPT conditions based on careful literature review as well as clearly thought-out experiments to investigate each parameter that can effect a products performance. Our IVPT studies have also included developing in-use product application and testing protocols and have assessed direct comparisons of CQAs with product performance.

Locally within the Australian topical and consumer product regulatory scene, Dr Mohammed’s work published in the Journal of Investigative dermatology has helped dispel false alarms regarding the safety and toxicity of ZnO nanoparticles. The story was captured by numerous (>400) printed and online media articles. This work, coming out at the peak of summer in Australia led to improved consumer confidence regarding better sun protection habits.

Works

Search Professor Yousuf Mohammed’s works on UQ eSpace

84 works between 2012 and 2024

41 - 60 of 84 works

2022

Journal Article

Treating primary lymphoma of the brain in AIDS patients via multifunctional oral nanoparticulate systems

Jha, Saurav Kumar, Imran, Mohammad, Paudel, Keshav Raj, Mohammed, Yousuf, Hansbro, Philip and Dua, Kamal (2022). Treating primary lymphoma of the brain in AIDS patients via multifunctional oral nanoparticulate systems. Nanomedicine, 17 (7), 425-429. doi: 10.2217/nnm-2021-0444

Treating primary lymphoma of the brain in AIDS patients via multifunctional oral nanoparticulate systems

2022

Journal Article

Application of confocal raman microscopy for the characterization of topical semisolid formulations and their penetration into human skin ex vivo

Jung, Nathalie, Namjoshi, Sarika, Mohammed, Yousuf, Grice, Jeffrey E., Benson, Heather A. E., Raney, Sam G., Roberts, Michael S. and Windbergs, Maike (2022). Application of confocal raman microscopy for the characterization of topical semisolid formulations and their penetration into human skin ex vivo. Pharmaceutical Research, 39 (5), 935-948. doi: 10.1007/s11095-022-03245-7

Application of confocal raman microscopy for the characterization of topical semisolid formulations and their penetration into human skin ex vivo

2021

Journal Article

Topical drug delivery: history, percutaneous absorption, and product development

Roberts, Michael S., Cheruvu, Hanumanth S., Mangion, Sean E., Alinaghi, Azadeh, Benson, Heather A.E., Mohammed, Yousuf, Holmes, Amy, van der Hoek, John, Pastore, Michael and Grice, Jeffrey E. (2021). Topical drug delivery: history, percutaneous absorption, and product development. Advanced Drug Delivery Reviews, 177 113929, 113929. doi: 10.1016/j.addr.2021.113929

Topical drug delivery: history, percutaneous absorption, and product development

2021

Journal Article

Viscoelastic and deformation characteristics of structurally different commercial topical systems

Dabbaghi, Maryam, Namjoshi, Sarika, Panchal, Bhavesh, Grice, Jeffrey E., Prakash, Sangeeta, Roberts, Michael Stephen and Mohammed, Yousuf (2021). Viscoelastic and deformation characteristics of structurally different commercial topical systems. Pharmaceutics, 13 (9) 1351, 1351. doi: 10.3390/pharmaceutics13091351

Viscoelastic and deformation characteristics of structurally different commercial topical systems

2020

Journal Article

Development of an oil-in-water self-emulsifying microemulsion for cutaneous delivery of Rose Bengal: investigation of anti-melanoma properties

Forouz, Farzaneh, Dabbaghi, Maryam, Namjoshi, Sarika, Mohammed, Yousuf, Roberts, Michael S. and Grice, Jeffrey E. (2020). Development of an oil-in-water self-emulsifying microemulsion for cutaneous delivery of Rose Bengal: investigation of anti-melanoma properties. Pharmaceutics, 12 (10) 947, 1-17. doi: 10.3390/pharmaceutics12100947

Development of an oil-in-water self-emulsifying microemulsion for cutaneous delivery of Rose Bengal: investigation of anti-melanoma properties

2020

Journal Article

Using in vivo multiphoton fluorescence lifetime imaging to unravel disease-specific changes in the liver redox state

Barkauskas, Deborah S., Medley, Gregory, Liang, Xiaowen, Mohammed, Yousuf H., Thorling, Camilla A., Wang, Haolu and Roberts, Michael S. (2020). Using in vivo multiphoton fluorescence lifetime imaging to unravel disease-specific changes in the liver redox state. Methods and Applications in Fluorescence, 8 (3) 034003, 034003. doi: 10.1088/2050-6120/ab93de

Using in vivo multiphoton fluorescence lifetime imaging to unravel disease-specific changes in the liver redox state

2020

Journal Article

Quality by design: development of the quality target product profile (QTPP) for semisolid topical products

Namjoshi, Sarika, Dabbaghi, Maryam, Roberts, Michael S., Grice, Jeffrey E. and Mohammed, Yousuf (2020). Quality by design: development of the quality target product profile (QTPP) for semisolid topical products. Pharmaceutics, 12 (3) 287, 287. doi: 10.3390/pharmaceutics12030287

Quality by design: development of the quality target product profile (QTPP) for semisolid topical products

2020

Journal Article

Advances and controversies in studying sunscreen delivery and toxicity

Yamada, Miko, Mohammed, Yousuf and Prow, Tarl W. (2020). Advances and controversies in studying sunscreen delivery and toxicity. Advanced Drug Delivery Reviews, 153, 72-86. doi: 10.1016/j.addr.2020.02.001

Advances and controversies in studying sunscreen delivery and toxicity

2020

Journal Article

Novel nanocarriers for targeted topical skin delivery of the antioxidant resveratrol

Nastiti, Christofori M. R. R., Ponto, Thellie, Mohammed, Yousuf, Roberts, Michael S. and Benson, Heather A. E. (2020). Novel nanocarriers for targeted topical skin delivery of the antioxidant resveratrol. Pharmaceutics, 12 (2) 108, 108. doi: 10.3390/pharmaceutics12020108

Novel nanocarriers for targeted topical skin delivery of the antioxidant resveratrol

2020

Journal Article

Noninvasive in vivo human multiphoton microscopy: a key method in proving nanoparticulate zinc oxide sunscreen safety

Mohammed, Yousuf, Barkauskas, Deborah, Holmes, Amy, Grice, Jeffrey and Roberts, Michael (2020). Noninvasive in vivo human multiphoton microscopy: a key method in proving nanoparticulate zinc oxide sunscreen safety. Journal of Biomedical Optics, 25 (1) 014509, 014509-014509. doi: 10.1117/1.JBO.25.1.014509

Noninvasive in vivo human multiphoton microscopy: a key method in proving nanoparticulate zinc oxide sunscreen safety

2020

Journal Article

Bathing does not facilitate human skin penetration or adverse cellular effects of nanoparticulate zinc oxide sunscreens after topical application

Mohammed, Yousuf H., Haridass, Isha N., Grice, Jeffrey E., Benson, Heather A.E. and Roberts, Michael S. (2020). Bathing does not facilitate human skin penetration or adverse cellular effects of nanoparticulate zinc oxide sunscreens after topical application. Journal of Investigative Dermatology, 140 (8), 1656-1659. doi: 10.1016/j.jid.2019.12.024

Bathing does not facilitate human skin penetration or adverse cellular effects of nanoparticulate zinc oxide sunscreens after topical application

2020

Conference Publication

Multiphoton and FLIM imaging in quantifying ex vivo and in vivo body organ kinetics of solutes

Roberts, Michael S., Barkauskas, Deborah, Wang, Haolu, Liu, Xin, Studier, Hauke, Pastore, Michael, Zhang, Run, Holmes, Amy, Grice, Jeffrey E., Xu, Zhiping, Mohammed, Yousuf S. and Liang, Xiaowen (2020). Multiphoton and FLIM imaging in quantifying ex vivo and in vivo body organ kinetics of solutes. Multiphoton Microscopy in the Biomedical Sciences, San Francisco, CA United States, 2-4 February 2020. Bellingham, WA United States: SPIE. doi: 10.1117/12.2546058

Multiphoton and FLIM imaging in quantifying ex vivo and in vivo body organ kinetics of solutes

2019

Journal Article

Mechanistic evaluation of enhanced curcumin delivery through human skin in vitro from optimised nanoemulsion formulations fabricated with different penetration enhancers

Yousef, Shereen A., Mohammed, Yousuf H., Namjoshi, Sarika, Grice, Jeffrey E., Benson, Heather A. E., Sakran, Wedad and Roberts, Michael S. (2019). Mechanistic evaluation of enhanced curcumin delivery through human skin in vitro from optimised nanoemulsion formulations fabricated with different penetration enhancers. Pharmaceutics, 11 (12) 639, 639. doi: 10.3390/pharmaceutics11120639

Mechanistic evaluation of enhanced curcumin delivery through human skin in vitro from optimised nanoemulsion formulations fabricated with different penetration enhancers

2019

Journal Article

Targeted topical delivery of retinoids in the management of acne vulgaris: Current formulations and novel delivery systems

Latter, Gemma, Grice, Jeffrey E., Mohammed, Yousuf, Roberts, Michael S. and Benson, Heather A. E. (2019). Targeted topical delivery of retinoids in the management of acne vulgaris: Current formulations and novel delivery systems. Pharmaceutics, 11 (10) 490, 490. doi: 10.3390/pharmaceutics11100490

Targeted topical delivery of retinoids in the management of acne vulgaris: Current formulations and novel delivery systems

2019

Journal Article

Cellular metabolism and pore lifetime of human skin following microprojection array mediation

Haridass, Isha N., Wei, Jonathan C. J., Mohammed, Yousuf H., Crichton, Michael L., Anderson, Christopher D., Henricson, Joakim, Sanchez, Washington Y., Meliga, Stefano C., Grice, Jeffrey E., Benson, Heather A. E., Kendall, Mark A. F. and Roberts, Michael S. (2019). Cellular metabolism and pore lifetime of human skin following microprojection array mediation. Journal of Controlled Release, 306, 59-68. doi: 10.1016/j.jconrel.2019.05.024

Cellular metabolism and pore lifetime of human skin following microprojection array mediation

2019

Journal Article

Evaluation of quantum dot skin penetration in porcine skin: effect of age and anatomical site of topical application

Nastiti, Christofori M.R.R., Mohammed, Yousuf, Telaprolu, Krishna C., Liang, Xiaowen, Grice, Jeffrey E., Roberts, Michael S. and Benson, Heather A.E. (2019). Evaluation of quantum dot skin penetration in porcine skin: effect of age and anatomical site of topical application. Skin Pharmacology and Physiology, 32 (4), 1-10. doi: 10.1159/000499435

Evaluation of quantum dot skin penetration in porcine skin: effect of age and anatomical site of topical application

2019

Journal Article

Permeation mechanism of caffeine and naproxen through in vitro human epidermis: Effect of vehicles and penetration enhancers

Abd, Eman, Benson, Heather A.E., Mohammed, Yousuf H., Roberts, Michael S. and Grice, Jeffrey E. (2019). Permeation mechanism of caffeine and naproxen through in vitro human epidermis: Effect of vehicles and penetration enhancers. Skin Pharmacology and Physiology, 32 (3), 132-141. doi: 10.1159/000497225

Permeation mechanism of caffeine and naproxen through in vitro human epidermis: Effect of vehicles and penetration enhancers

2019

Journal Article

Optical characterisation of zinc pyrithione

Sandiford, Lydia , Holmes, Amy M. , Mangion, Sean E. , Mohammed, Yousuf H. , Zvyagin, Andrei V. and Roberts, Michael S. (2019). Optical characterisation of zinc pyrithione. Photochemistry and Photobiology, 95 (5) php.13100, 1142-1150. doi: 10.1111/php.13100

Optical characterisation of zinc pyrithione

2019

Journal Article

Support for the safe use of zinc oxide nanoparticle sunscreens: lack of skin penetration or cellular toxicity after repeated application in volunteers

Mohammed, Yousuf H., Holmes, Amy, Haridass, Isha N., Sanchez, Washington Y., Studier, Hauke, Grice, Jeffrey E., Benson, Heather A. E. and Roberts, Michael S. (2019). Support for the safe use of zinc oxide nanoparticle sunscreens: lack of skin penetration or cellular toxicity after repeated application in volunteers. Journal of Investigative Dermatology, 139 (2), 308-315. doi: 10.1016/j.jid.2018.08.024

Support for the safe use of zinc oxide nanoparticle sunscreens: lack of skin penetration or cellular toxicity after repeated application in volunteers

2019

Journal Article

Topical and transdermal drug delivery: from simple potions to smart technologies

Benson, Heather A. E., Grice, Jeffrey E., Mohammed, Yousuf, Namjoshi, Sarika and Roberts, Michael S. (2019). Topical and transdermal drug delivery: from simple potions to smart technologies. Current Drug Delivery, 16 (5), 444-460. doi: 10.2174/1567201816666190201143457

Topical and transdermal drug delivery: from simple potions to smart technologies

Funding

Current funding

  • 2019 - 2025
    Elucidating Sensorial and Functional Characteristics of Topical Formulations
    United States Food and Drug Administration
    Open grant

Past funding

  • 2019 - 2023
    Bioequivalence of Topical Products: Elucidating the Thermodynamic and Functional Characteristics of Compositionally Different Topical Formulations (USFDA grant admin. by University of South Australia)
    University of South Australia
    Open grant
  • 2018 - 2021
    Formulation drug product quality attributes in dermal physiologically-based pharmacokinetic models for topical dermatological drug products and transdermal delivery systems
    United States Food and Drug Administration
    Open grant

Supervision

Availability

Associate Professor Yousuf Mohammed is:
Available for supervision

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Available projects

  • Advanced microneedle platform for localized delivery

    This project is an exceptionally innovative combination of pharmaceutical science, materials science, nanotechnology, and clinical science to develop a state-of-the art drug delivery technology for an optimal treatment and overdose risk management of highly potent medicinal compounds. The project will trigger a paradigm shift towards safer dosing of abuse and misuse prone drugs, which suffer from unreliable bioavailability due to solubility or permeation challenges.

  • Bioequivalence of Topical products: Elucidating the Thermodynamic and Functional Characteristics of Compositionally Different Topical Formulations

    The purpose of this project is to support the research necessary to elucidate how systematic alterations to the qualitative (Q1) and/or quantitative (Q2) composition of topical formulations impacts their physical, structural, and functional properties. A key aspect of the research relates to understanding how the thermodynamic properties of a topical dosage form change as it undergoes metamorphosis during dose application and drying on the skin, how the drug's thermodynamic activity profile during the metamorphosis of the dosage form may compare between compositionally different (non-Q1 and/or non-Q2) topical formulations, and how these and other forces may modulate the rate and extent to which topically applied drugs may become available at or near their site(s) of action in the skin. Another key aspect of the research relates to identifying and understanding other potential failure modes for bioequivalence (BE) and/or therapeutic equivalence (TE) (e.g., differences in irritation potential) that may arise between compositionally different (non-Q1 and/or non-Q2) topical formulations.

  • Bioequivalence of Topical Products: Elucidating the Sensorial and Functional Characteristics of Compositionally Different Topical Formulations

    The purpose of this project is to support research relevant to topical semisolid drug products that will help elucidate the relationship between a product's quality attributes and its functional properties. A specific purpose is to elucidate how characterizations of the arrangement of matter, including rheological characterizations (e.g., texture analysis, tribology) may correlate with and/or be predictive of sensorial differences perceived by human subjects (or patients). Upon the successful completion of this research, it should be possible to predict, based upon product quality characterizations, whether test and reference products that may be compositionally different are likely to have a comparable look and feel, including comparable perceptions of grittiness, silky-smoothness, and cooling sensation.

Supervision history

Current supervision

  • Doctor Philosophy

    Development and Assessment of Topical Delivery Systems for Various Skin Diseases

    Principal Advisor

  • Doctor Philosophy

    Strategies for Vitamin D transdermal supplementation

    Principal Advisor

  • Doctor Philosophy

    Transdermal delviery of NAD+ precursor molecule Nicotinamide Mononucleotide using Advanced Microneedle arrays

    Principal Advisor

  • Doctor Philosophy

    Development and Assessment of Topical Delivery Systems for Various Skin Diseases

    Principal Advisor

  • Doctor Philosophy

    Simultaneous absorption and evaporation PBPK models for topical drugs and inactive agents

    Principal Advisor

    Other advisors: Dr Abbas Shafiee

  • Doctor Philosophy

    Thermodynamic dependence of Topical Formulations

    Principal Advisor

    Other advisors: Associate Professor Peter Moyle, Dr Hui Peng

  • Doctor Philosophy

    Development of topical delivery system (TDS): Role of intrinsic and extrinsic factors on performance

    Principal Advisor

    Other advisors: Professor Roger Wepf

Completed supervision

Media

Enquiries

Contact Associate Professor Yousuf Mohammed directly for media enquiries about:

  • Bioequivalence of Pharmaceutical Products
  • Cosmetics
  • Dermatology
  • FLIM
  • Healthcare products
  • Multiphoton Microscopy
  • Personal care products
  • Regulatory Guidelines
  • Rheology
  • Skin feel
  • Skin Imaging
  • Skin Toxicology
  • Topical Products
  • Toxicology
  • Tribology
  • •Drug delivery devices

Need help?

For help with finding experts, story ideas and media enquiries, contact our Media team:

communications@uq.edu.au