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Dr Irina Ermolina

Job: Senior Lecturer

Faculty: Health and Life Sciences

School/department: Leicester School of Pharmacy

Address: De Montfort University, The Gateway, Leicester, LE1 9BH.

T: +44 (0)116 257 7870

E: IErmolina@dmu.ac.uk

W: www.dmu.ac.uk/pharmaceutical

 

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Personal profile

Dr Irina Ermolina is a senior lecturer in Pharmaceuticals in the School of Pharmacy, De Montfort University. She gained her PhD degree in Molecular Physics in Institute of Biochemistry and Biophysics, Russian Academy of Sciences, Kazan, Russia. Prior to joining the DMU as an academic staff, Dr Ermolina was employed as Postdoctoral Research Fellow at Glasgow University and Southampton University. Previously she worked as a senior researcher in Institute of Biochemistry and Biophysics, Kazan, Russian Academy of Sciences.

Dr Ermolina now specializes in characterization of physical properties of pharmaceutical solids and powders studied by different analytical techniques; development and characterization of hydrogels as drug delivery systems; dielectric properties biological systems (proteins, DNA, cells, disaccharides); stability characterization of freeze-dried pharmaceuticals; the dynamic structure of proteins in solutions and membrane films.

Research group affiliations

  • Pharmaceutical Technology

Publications and outputs

  • Application of Design of Experiment for development of orally disintegrating tablets
    dc.title: Application of Design of Experiment for development of orally disintegrating tablets dc.contributor.author: Ermolina, I.; Hackl, E. dc.description.abstract: The current work presents the formulation development methodology for Orally Disintegrating Tablets (ODTs) using Design of Experiment (DoE). The statistical software JMP was used to design the experiments and analyse the data for producing sodium Ibuprofen freeze-dried ODTs. In the first stage, several pure excipients (polymers, amino acids, and polyols) were freeze-dried and the quality attributes of the cakes were evaluated. Four critical quality attributes (CQAs) were determined based on the target profile: disintegration time, mechanical strength, moisture uptake, appearance. In the second stage, the placebo tablets comprising sodium alginate, alanine, and mannitol (working as a matrix shape-former and lyo-/cryo-protectors), were designed using Mixture DoE, freeze-dried and characterized to identify the optimal combination of the excipients. In the third stage, the ODTs containing sodium Ibuprofen were designed within a reduced design space to optimize the formulation. The wettability and dissolution of the ODTs were studied. The proposed methodology enabled the estimation of working design space and facilitated the production of freeze-dried ODTs with the required quality attributes. Sodium alginate was identified as the key excipient in the formulation, affecting all CQAs. The optimal combination of sodium alginate, alanine and mannitol corresponding to the desirable target profile was found (30%:40%:30%). dc.description: open access article
  • Effect of lubricants on the properties of tablets compressed from varied size granules
    dc.title: Effect of lubricants on the properties of tablets compressed from varied size granules dc.contributor.author: Hackl, E.; Ermolina, I.; Kabova, E. dc.description.abstract: Magnesium stearate (MgSt) is one of the most widely used solid lubricants in oral solid dosage forms. However, MgSt can negatively impact the tablets, decreasing their mechanical properties and lengthening disintegration/dissolution times. The aim of the present study was to compare the effect of MgSt and Sodium Stearyl Fumarate (SSF) lubricants on the physical characteristics of immediate release caffeine tablets compressed using granules of different sizes. Overall, the results demonstrate that using SSF as a lubricant significantly enhances tablet mechanical strength and reduces disintegration/wetting times for all granule sizes used to compress tablets. With smaller granules, SSF tends to be more effective. Over-lubrication with SSF leads to a decrease in tablet hardness as well, though to a significantly lesser extent than over-lubrication with MgSt. dc.description: open access article
  • Inclusion by design: Embedding inclusive teaching practice into design and preparation of laboratory classes
    dc.title: Inclusion by design: Embedding inclusive teaching practice into design and preparation of laboratory classes dc.contributor.author: Ermolina, I.; Hackl, E. V. dc.description.abstract: Introduction: Creation of an inclusive learning environment and provision of individual adjustments are duties of higher education providers. However, laboratory practical teaching is not always inclusive beyond general university requirements. Lab classes can present many barriers to disabled learners. Proactive adjustments embedded into the design and preparation of laboratory classes can make lab-based teaching as inclusive and accessible as possible. Perspective: The main challenges, difficulties, and barriers experienced by students with disabilities during laboratory classes were identified and analysed. A review of a large number of sources was conducted, and the best available evidence of inclusive practice in science and medicine laboratories (including those already implemented in the Reading School of Pharmacy and Leicester School of Pharmacy) were retrieved, critically appraised, and summarized. Recommendations on embedding inclusive practices into the design and preparation of laboratory classes were developed, including methods for making the following accessible: (1) printed materials, such as handouts, instructions, notes, etc.; (2) video files; and (3) colours. Additionally, the use of a range of pedagogic techniques and assistive technologies in inclusive teaching is discussed. Implications: We have developed general accessibility guides and provided laboratory teaching staff with examples of good inclusive teaching practice. Active implementation of the inclusiveby- design approach, in contrast to inclusive-on-request, can be beneficial for both learners and teaching staff since inclusion-by-design helps to establish a lasting inclusive culture in teaching laboratories.
  • Dielectric spectroscopy of the low-losses sugar lyophilises: IV. Comparative study of four disaccharides at different moisture contents and temperatures
    dc.title: Dielectric spectroscopy of the low-losses sugar lyophilises: IV. Comparative study of four disaccharides at different moisture contents and temperatures dc.contributor.author: Ermolina, I.; Smith, Geoff dc.description.abstract: The purpose of this article is to study the effect of moisture content on the molecular dynamics of freeze-dried disaccharide excipients, in the context of understanding the instability of a pharmaceutical product. Four di saccharides were measured by broad band dielectric spectroscopy, over a wide temperature range (− 140 to +80 ◦C) with increasing moisture content from 1 to 7.5%. The two observed sub-Tg relaxation processes (β and γ) were affected by the moisture content, with a dramatic change in relaxation time of the β-process, but only a moderate effect on the γ-process. A suggestion of the likely arrangement of dipoles, and intra-molecular mobility, was performed in the framework of the free-space theory and based primarily on the analysis of the relaxation times, activation energies and Frohlich parameters. This analysis allows for some speculation concerning the disaccharide moisture buffering in freeze-dried formulations. dc.description: open access article
  • Observations on the Changing Shape of the Ice Mass and the Determination of the Sublimation End Point in Freeze-Drying: An Application for Through-Vial Impedance Spectroscopy (TVIS)
    dc.title: Observations on the Changing Shape of the Ice Mass and the Determination of the Sublimation End Point in Freeze-Drying: An Application for Through-Vial Impedance Spectroscopy (TVIS) dc.contributor.author: Pandya, Bhaskar; Smith, Geoff; Ermolina, I.; Polygalov, Evgeny dc.description.abstract: Models for ice sublimation from a freeze-drying vial rely on the assumption of a planar ice interface up to ~25% loss of ice mass (which is difficult to qualify) whereas single-vial determinations of the sublimation endpoint (by temperature sensors) are based on the point when the observed temperature reaches a plateau, which cannot differentiate between sublimation and desorption-drying. In this work, the real part capacitance of TVIS vial(s) containing frozen water (during sublimation drying) was measured at 100 kHz. This parameter C′(100kHz) was shown to be highly sensitive to the shape and volume of the ice mass and is therefore a useful parameter for monitoring ice sublimation. By placing a digital camera in front of an isolated TVIS vial containing ice, it was possible to relate the changes in the shape of the ice mass with the changes in the trajectory of the time profile of C′(100kHz) and determine the point of deviation from a planar ice interface and ultimately determine the point when the last vestiges of ice disappear. Thereafter, the same characteristics of the C′(100kHz) time-profile were identified for those TVIS vials located out of sight of the camera in a separate full-shelf lyo study, thereby obviating the need for photographic examination. dc.description: open access article
  • Application of Through Vial Impedance Spectroscopy for Lyophilization Process Development
    dc.title: Application of Through Vial Impedance Spectroscopy for Lyophilization Process Development dc.contributor.author: Pandya, Bhaskar; Smith, Geoff; Polygalov, E.; Ermolina, I.
  • New Impedance Based Methodologies to Determine the Vial Heat Transfer Coefficient and the Endpoint of Primary Drying
    dc.title: New Impedance Based Methodologies to Determine the Vial Heat Transfer Coefficient and the Endpoint of Primary Drying dc.contributor.author: Pandya, Bhaskar; Smith, Geoff; Polygalov, E.; Ermolina, I.
  • Prediction of the Collapse of Freeze-Dried Lactose Solution using Through Vial Impedance Spectroscopy (TVIS)
    dc.title: Prediction of the Collapse of Freeze-Dried Lactose Solution using Through Vial Impedance Spectroscopy (TVIS) dc.contributor.author: Jeeraruangrattana, Y.; Polygalov, E.; Ermolina, I.; Smith, Geoff dc.description.abstract: The aim of this work is to evaluate the application of TVIS system for the prediction of micro-collapse during a freeze-drying cycle. The electrical impedance of a 5%w/v lactose solution contained within a modified glass freeze-drying vial was measured over the frequency range of 10 Hz to 1 MHz during the entire freeze-drying process. A significant decrease in CʺPEAK at the point of micro-collapse (as confirmed by SEM) highlights the potential for using TVIS for monitoring microscopic changes in the product resistance to vapour flow associated with the phenomenon of micro-collapse. This study also demonstrated a good correlation between TVIS data (Log FPEAK) and temperature of the frozen solution during the annealing stage of the cycle. By using a temperature calibration from the annealing stage it was possible to predict the onset of collapse and thereby demonstrate the potential for TVIS to be used as a process control tool that would allow the cycle to be driven at the highest achievable temperature whilst avoiding collapse.
  • Application of Impedance Based Technology to investigate the Collapse of Freeze-dried Sugar-salt Solutions
    dc.title: Application of Impedance Based Technology to investigate the Collapse of Freeze-dried Sugar-salt Solutions dc.contributor.author: Jeeraruangrattana, Y.; Polygalov, E.; Ermolina, I.; Smith, Geoff
  • Determination of ice interface temperature, sublimation rate and the dried product resistance, and its application in the assessment of microcollapse using through-vial impedance spectroscopy
    dc.title: Determination of ice interface temperature, sublimation rate and the dried product resistance, and its application in the assessment of microcollapse using through-vial impedance spectroscopy dc.contributor.author: Smith, Geoff; Jeeraruangrattana, Yowwares; Polygalov, E.; Ermolina, I. dc.description.abstract: Through-vial impedance spectroscopy (TVIS) is a new approach for characterizing product attributes during freeze-drying process development. In this study, a pair of copper foil electrodes was attached to the external surface of a Type I glass tubing vial, of nominal capacity 10 mL and containing 3.5 g of an aqueous solution of 5% w/v lactose, and the impedance spectrum of the vial and contents recorded during a lyophilization cycle. The cycle included a temperature ramp in the primary drying stage in order to induce a collapse event in the dry layer. Using the peak in the dielectric loss spectrum, associated with the dielectric relaxation of ice, methods were developed to predict the sublimation rate and the ice interface temperature at the sublimation front, from which the dry layer resistance was then calculated. A four-fold increase in sublimation rate and a reduction in the dry layer resistance wereobserved once the ice interface temperature reached −33 °C, which coincides with the onset of the glass transition (as determined by DSC) and the time point at which micro-collapse occurred (as evidenced by SEM images at the end of the cycle). This work suggests a prospective application of impedance measurements in driving process efficiencies by operating the dryer at the highest achievable temperature (i.e. the collapse temperature) whilst avoiding macro-collapse. dc.description: The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.

View a full listing of Irina Ermolina's publications and outputs.

Research interests/expertise

  • Freeze-drying Pharmaceuticals
  • Dielectric spectroscopy
  • Thermoanalytical methods
  • Terahertz spectroscopy
  • Characterization of hydrogels.

Areas of teaching

  • Pharmaceutical technology
  • Analytical techniques for pharmaceutical applications
  • Material science for pharmaceutical applications
  • MSc Quality by Design course

Qualifications

MSc PhD

Honours and awards

  • Lady Davis Grant 1997-1999, Hebrew University, Jerusalem, Israel.

Membership of professional associations and societies

  • Member of IoP (Institute of Physics, since 2006).

Professional licences and certificates

  • PGCertHE, De Montfort University
  • PIAT, University of Manchester

Conference attendance

Oral presentations at the following Conferences:

  • I.Ermolina. Dielectric spectroscopy and its applications to biopolymers and polymers characterization, RAPS (Recent Appointees in Polymer Science), Nottingham, Sept 2008.
  • I. Ermolina, G. Smith, Moisture buffering of freeze-dried pharmaceutical products: A study by broadband dielectric spectroscopy. 6IDMRCS,Rome Aug 2009.
  • I. Ermolina, V .Khutoryanskiy.Dielectric, terahertz and microscopic studies of phase transition
    in aqueous solutions of poly(vinyl methyl ether), RAPS (Recent Appointees in Polymer Science), Nottingham, Sept  2009.
  • I. Ermolina and V. Khutoryanskiy. Investigating temperature-induced phase transition in aqueous solutions of poly(vinyl methyl ether) by dielectric, terahertz and microscopic techniques. BDS-2010, Sept Madrid, 2010.
  • J. Darkwah, G. Smith, I. Ermolina, Terahertz Pulsed Spectroscopy Study of Amino Acids and Gelatin. PharmSci, Nottingham, 2010.
  • I. Ermolina, A. Pandya, G. Smith, Comparative study of freeze-dried disaccharides by dielectric spectroscopy with respect to molecular mobility and stability, PharmSci, Nottingham, 2010.
  • I. Ermolina, V. Khutoryanskiy. Effect of copolymer composition on physicochemical properties of 2-hydroxyethylacrylate-co-2-hydroxyethylmethacrylate hydrogels
    studied by Dielectric Spectroscopy and Thermogravimetric Analysis.  RAPS (Recent Appointees in Polymer Science), Loughborough, Sept. 2011.

Poster award:
I. Ermolina, E. Hackl, V. Khutoryanskiy. Study of 2-hydroxyethylacrylate-co-2-hydroxyethylmethacrylate hydrogels using thermoanalytical methods, dielectric spectroscopy and drug release assay, UK-PharmSci-2012, Nottingham, 2012.

Consultancy work

Freeze-drying Pharmaceuticals, Dielectric spectroscopy, Thermoanalytical methods, Terahertz spectroscopy, and characterization of hydrogels.
Currently Available: Yes

Current research students

Supervision of 6 PhD students:

  1. Joseph Darkwah, 1st supervisor
  2. Amee Pandya, 2nd supervisor
  3. Alex Wall, 2nd supervisor
  4. Sohail Arshad, 2nd supervisor
  5. Amjad Husain, 2nd supervisor
  6. Banji Kelan, 2nd supervisor

Internally funded research project information

  • DMU PhD Scholarship (full bursary),2009Terahertz imaging of the roller compaction process, Second supervisor
  • DMU PhD Scholarship (fees-only),2011Process Control/Monitoring in the Manufacture of Protein Based Therapeutics, First supervisor.

Professional esteem indicators

Journal Referee for:
Carbohydrate Research; J Physics D; J Non-Crystal. Solids; J Phys. Chem. D; Biophysical J.

Irina Ermolina