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Dr Irina Ermolina

Job: Senior Lecturer

Faculty: Health and Life Sciences

School/department: Leicester School of Pharmacy

Address: Â鶹´«Ã½, 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, Â鶹´«Ã½. She gained her PhD degree in Molecular Physics in Institute of Biochemistry and Biophysics, Russian Academy of Sciences, Kazan, Russia. Prior to joining the Â鶹´«Ã½ 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


  • 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.

  • dc.title: Application of Through Vial Impedance Spectroscopy for Lyophilization Process Development dc.contributor.author: Pandya, Bhaskar; Smith, Geoff; Polygalov, E.; Ermolina, I.

  • 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.

  • 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.

  • 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

  • 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.

  • dc.title: Application of Texture Analysis technique in formulation development of lyophilized orally disintegrating tablets containing mannitol, polyvinylpyrrolidone and amino acids dc.contributor.author: Hackl, E. V.; Ermolina, I. dc.description.abstract: Orally disintegrating tablets (ODTs) attract a great attention as this easy swallowing dosage form often improves patient compliance. In the current work, orally disintegrating tablets comprising mannitol, polyvinylpyrrolidone (PVP) and an amino acid (alanine, glycine or serine) with various PVP-to-amino acid ratios were formulated. The combination of mannitol and an amino acid was aimed to use the advantages of mannitol, the matrix-supporting and disintegration agent, and to reduce the total amount of sugar/polyol in tablets. Tablets were manufactured by freeze-drying and their properties (appearance, internal structure, disintegration, mechanical and texture properties, moisture uptake, shrinkage, thermal properties) were assessed. In the work, great emphasis was placed on illustrating the applicability of the Texture Analysis of the freeze-dried cakes directly in vials in formulation development. The results show that the appearance, mechanical properties, disintegration and shrinkage of the freeze-dried ODTs depend significantly on the excipient composition with PVP playing the leading role. Partial mannitol replacement with an amino acid has a limited impact on the tablet properties. The presence of an amino acid also has no impact on the PVP-mannitol interaction. The mechanical and texture properties of freeze-dried ODTs depend non-linearly on the PVP content. The transition between the different types of textures occurs in a narrow range of PVP concentrations regardless of the type of amino acid in a formulation. The non-linear effect of PVP on various tablet properties should be taken into account when designing ODT formulations as it can compromise the robustness of the manufacturing process. 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.

  • dc.title: Solubility and dissolution rate enhancement of ibuprofen by co-milling with polymeric excipients dc.contributor.author: Smith, Geoff; Pedge, Nicholas; Khan, Karrar A; Bukhari, Nadeem Irfan; Hussain, Amjad; Ermolina, I. dc.description.abstract: The aim of this study was to enhance the kinetic solubility and dissolution rate of ibuprofen by co-milling with different excipients and to establish the underlying mechanism(s) for such enhancement. In the first-part, two excipients (HPMC and soluplus) were selected from seven, and the optimal ball-milling parameters of speed and time (18 Hz, 15 min) were determined based on solubility-enhancement and flow-ability criteria. In the second-part, co-milling of different weight-ratios of ibuprofen-to-excipient was carried out and solubility and dissolution rates were determined. Mechanisms of biopharmaceutical enhancement were studied by SEM, laser diffraction, DSC, and FTIR analysis of the co-mixtures. Ibuprofen solubility (0.09 mg/mL for un-milled) was increased by factors of 4–5 and 10–20 for HPMC and soluplus, respectively. The weakening of crystals, stabilization of the amorphous phase and an increase in solid-state hydrogen bonding are the likely mechanisms for this enhancement. Reductions in Q70% dissolution time were also observed, by a factor of 4 and 7 for ibuprofen:HMPC and ibuprofen:soluplus co-milled mixtures, respectively. Although, there were similar reductions in particle size, dispersibility and degree of amorphization in both mixtures, the higher dissolution rate for soluplus, over that for HPMC, must be due to the additional solubilization contribution to the kinetic solubility provided by soluplus. 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.

  • dc.title: Correlation between molecular dynamics and physical stability of two milled anhydrous sugars: lactose and sucrose dc.contributor.author: Smith, Geoff; Hussain, Amjad; Bukhari, Nadeem Irfan; Ermolina, I. dc.description.abstract: The process of milling often results in amorphization and the physical stability of amorphous phase is linked with its molecular dynamics. This study focuses on a propensity of two disaccharides (lactose and sucrose) to amorphize on ball milling and the stability of the resultant amorphous phase. The amorphous content in milled sugars is estimated by Differential Scanning Calorimetry (DSC) and the stability was measured in terms of the tendency to recrystallize by Broadband Dielectric Spectroscopy (BDS). The results show that the amorphous content increases with milling time and is greater for lactose than sucrose. At the same degree of amorphization, sucrose recrystallize at temperature ∼15 °C higher than lactose, indicating higher stability. The molecular dynamics (beta relaxation process), suggest that milled sucrose is more stable with higher activation energy (∼9 kJ mol−1) than that of lactose. The moisture content of amorphous phase also impacts its molecular dynamics in terms of increase in activation energy as the moisture decrease with increasing the milling times. The study suggests a greater stability of amorphous sucrose and susceptibility of milled lactose to recrystallize, however, on extended milling when the moisture content decreases, lactose was seen to become relatively more stable. 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.

  • dc.title: Quantification of residual crystallinity in ball milled commercially sourced lactose monohydrate by thermo-analytical techniques and terahertz spectroscopy dc.contributor.author: Smith, Geoff; Hussain, A.; Bukhari, Nadeem Irfan; Ermolina, I. dc.description.abstract: The quantification of crystallinity is necessary in order to be able to control the milling process. The use of thermal analysis for this assessment presents certain challenges, particularly in the case of crystal hydrates. In this study, the residual crystallinity on ball milling of lactose monohydrate (LMH), for periods up to 90 min, was evaluated by thermo-analytical techniques (TGA, DSC) and terahertz spectroscopy (THz). In general, the results from one of the DSC analysis and the THz measurements agree showing a monotonous decrease in relative residual crystallinity with milling time (∼80% reduction after 60 min milling) and a slight increase at the 90 min time point. However, the estimates from TGA and two other methods of analyzing DSC curve do not agree with the former techniques and show variability with significantly higher estimates for crystallinity. It was concluded that, the thermal techniques require more complex treatment of the data in the evaluation of changes in crystallinity of a milled material (in particular to account for the de-vitrification and mutarotation of the material that inevitably occurs during the measurement cycle) while the analysis of THz data is more straightforward, with the measurement having no impact on the native state of the material.

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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, Â鶹´«Ã½
  • 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

  • Â鶹´«Ã½ PhD Scholarship (full bursary),2009Terahertz imaging of the roller compaction process, Second supervisor
  • Â鶹´«Ã½ 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