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: https://www.dmu.ac.uk/pharmaceutical

 

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 Texture Analysis technique in formulation development of lyophilized orally disintegrating tablets containing mannitol, polyvinylpyrrolidone and amino acids
    Application of Texture Analysis technique in formulation development of lyophilized orally disintegrating tablets containing mannitol, polyvinylpyrrolidone and amino acids Hackl, E. V.; Ermolina, I. 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. 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.
  • Correlation between molecular dynamics and physical stability of two milled anhydrous sugars: lactose and sucrose
    Correlation between molecular dynamics and physical stability of two milled anhydrous sugars: lactose and sucrose Smith, Geoff; Hussain, Amjad; Bukhari, Nadeem Irfan; Ermolina, I. 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. 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.
  • Solubility and dissolution rate enhancement of ibuprofen by co-milling with polymeric excipients
    Solubility and dissolution rate enhancement of ibuprofen by co-milling with polymeric excipients Smith, Geoff; Pedge, Nicholas; Khan, Karrar A; Bukhari, Nadeem Irfan; Hussain, Amjad; Ermolina, I. 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. 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.
  • Effect of Arginine on the Aggregation of Protein in Freeze-Dried Formulations Containing Sugars and Polyol: II. BSA Reconstitution and Aggregation
    Effect of Arginine on the Aggregation of Protein in Freeze-Dried Formulations Containing Sugars and Polyol: II. BSA Reconstitution and Aggregation Hackl, E. V.; Darkwah, Joseph; Smith, Geoff; Ermolina, I. The current paper continues our study on the ability of L-arginine to prevent/reduce the aggregation of proteins that results from the various stresses during the lyophilisation and/or storage of lyophilized protein-based products. The first part of our study, i.e. formulation development, was devoted to the rational design and optimization of an L-arginine containing lyophilized formulation which can resist the natural tendency of L-arginine to absorb atmosphere moisture. Mannitol and trehalose were chosen among other excipients to be included in the protein-based formulation, as mannitol in a combination with L-arginine has been shown to reduce moisture sorption while trehalose provides a degree of lyoprotection. In the present study, a number of formulations, which comprised bovine serum albumin (BSA) with and without L-arginine, and with five different ratios of trehalose-to-mannitol (from 30:70 to 80:20) were lyophilised and assessed. The internal structures and the moisture sorption/retention of the lyophilized formulations were characterised. To study the effect of L-arginine on BSA solid-phase stability, the lyophilized powder was exposed to accelerated storage conditions (high moisture (75% RH) and temperature (22 or 45 °C)) for up to 24 h. The lyophilized BSA formulations were then reconstituted and solution-state protein aggregation assessed by turbidimetry at 360 nm and fluorescence spectroscopy using the thioflavin T assay. It was demonstrated that L-arginine can be used in protein-based freeze-dried formulations to significantly reduce the aggregation of protein during the manufacturing, storage and subsequent reconstitution. The results also revealed the importance of a sufficient amount of mannitol in the arginine-containing formulations. 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.
  • The application of dual-electrode through vial impedance spectroscopy for the determination of ice interface temperatures, primary drying rate and vial heat transfer coefficient in lyophilization process development
    The application of dual-electrode through vial impedance spectroscopy for the determination of ice interface temperatures, primary drying rate and vial heat transfer coefficient in lyophilization process development Smith, Geoff; Jeeraruangrattana, Yowwares; Ermolina, I. Through vial impedance spectroscopy (TVIS) is a product non-invasive process analytical technology which exploits the frequency dependence of the complex impedance spectrum of a composite object (i.e. the freeze-drying vial and its contents) in order to track the progression of the freeze-drying cycle. This work demonstrates the use of a dual electrode system, attached to the external surface of a type I glass tubing vial (nominal capacity 10 mL) in the prediction of (i) the ice interface temperatures at the sublimation front and at the base of the vial, and (ii) the primary drying rate. A value for the heat transfer coefficient (for a chamber pressure of 270 µbar) was then calculated from these parameters and shown to be comparable to that published by Tchessalov (2017). 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.
  • The development and optimization of Orally disintegrating tablets by replacing sugars with amino acids
    The development and optimization of Orally disintegrating tablets by replacing sugars with amino acids Bajaj, Simran; Ermolina, I.
  • Development and manufacture of poly vinyl alcohol and poly methyl vinyl ether alt maleic anhydride hydrogels as wound dressing
    Development and manufacture of poly vinyl alcohol and poly methyl vinyl ether alt maleic anhydride hydrogels as wound dressing Barre, N.; Bhatti, A.; Ermolina, I. Wounds are breaks in the tissue due to physical or thermal damage. An acute wound can take anywhere from 8-12 weeks to fully heal whereas a chronic heal can take considerably longer. Healing occurs through several overlapping stages of haemostasis, inflammation, proliferation and maturation [1]. To aid the healing process and prevent further damage to the area the wound dressings tend to be used. These can be made from a variety of materials like films, foams, hydrogels and hydrocolloids. For a hydrogel to be used as for wound healing it needs to be: • easily removable without causing trauma • produced in a sterile form • physically strong even when wet • biocompatible [2] PVA has been used in repairing and regenerating tissues and organs and has shown good hydrophilicity, biodegradability and biocompatibility [3]. To aid with the thermo-gelling properties and improve mechanical strength and adhesiveness of the hydrogel, GANT will be used. PVA-GANT hydrogels are fully transparent which allows for visual monitoring of the wound without removal [4]. Hydrogels are usually described by their swelling capacity which can be established by how much water and aqueous liquids the gel can imbibe. Although this can be determined by a variety of factors, cross-linking density of the polymers has shown to be the most important parameter. In addition to this, hydrogels for bio-applications are required to have good mechanical properties i.e. high in strength, elasticity and mucoadhesiveness. However, as these parameters contradict each other, a compromise between the hydrophilicity and strength needs to be achieved. Autoclaving can be used to enable cross-linking between the polymers without the need for aids which can be toxic. Hydrogels formulated in this way tend to be sterile, antimicrobial and biocompatible [5] Quality by Design (QbD) is a systematic approach to product development that focuses on risk-based science and gaining process understanding whilst minimise time and resources through exploring predefined objectives [6]. Here, it will be used to assess how the critical quality attributes (CQAs) polymer ratio, total polymer concentration and critical process parameter (CPP) autoclaving time can impact physicochemical properties (swelling degree, and mechanical properties) and pharmaceutical aspects (drug release profile) of the hydrogel produced. Design of Experiment will be used to gain a better understanding of the process through a minimal number of experiments by utilising JMP Pro 13 to propose a Response Surface Design and explore the CQAs and CPP mentioned above. Finally, the pore structures of the hydrogels will be assessed with SEM, the type of water imbibed will be determined by DSC and TGA and the cross-linking density will be determined by FTIR before they are developed in their final dosage forms. References: [1]Kalarikkil, N et al. (2016) Nanomedicine and Tissue Engineering pp. 495 [2] Dhivya, S et al. (2015) Biomedicine (Taipei) 5(4) pp. 24-28 [3] Jiang, S et al. (2011) Mech. Behaviour of Biomed. Materials 4. Pp.1228-1233 [4] Moreno, E et al. (2014) International Journal of Pharmaceutics pp. 1-9 [5] Khutoryanskiy VV et al. (2016) RSC Advances, 6, 55211 [6] Sangshetti, J et al. (2017) Arab Journal of Chemistry 10(2) pp. s3412-s3425
  • Effect of arginine on the aggregation of protein in freeze-dried formulations containing sugars and polyol. 1. Formulation development
    Effect of arginine on the aggregation of protein in freeze-dried formulations containing sugars and polyol. 1. Formulation development Hackl, E. V.; Darkwah, Joseph; Smith, Geoff; Ermolina, I. L-arginine was introduced into protein-based freeze-dried formulations to study the ability of arginine to reduce / prevent from protein aggregation during manufacturing, storage and reconstitution of lyophilized protein-based pharmaceuticals. As L-arginine is known to be very hygroscopic, additional excipients which could provide a moisture buffering capacity need to be introduced into the formulation. In the first part of our study – excipient formulation development – the screening of a number of sugars/polyols has been done in order to select the best combination of excipients that, in a complex with L-arginine, can i) produce freeze-dried cakes with elegant appearance, adequate mechanical properties and reconstitution times, and ii) resist/minimize the moisture sorption. Various freeze-dried cakes containing L-arginine in combination with mannitol, trehalose, lactose, and sucrose were produced and analyzed by TGA, DSC, texture analysis, moisture sorption, cake shrinkage, TVIM and SEM. The non-linear dependencies of the physicochemical properties of the freeze-dried cakes on the sugar-to-mannitol ratios were found. The best combinations of excipients (L-arginine, mannitol and trehalose) were selected to be used in the second part of this work, in which the impact of each selected formulation will be studied in relation to the aggregation of a protein. 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.
  • Hydrogels based on copolymers of 2-hydroxyethylmethacrylate and 2-hydroxyethylacrylate as a delivery system for proteins: interactions with lysozyme
    Hydrogels based on copolymers of 2-hydroxyethylmethacrylate and 2-hydroxyethylacrylate as a delivery system for proteins: interactions with lysozyme Hackl, E. V.; Khutoryanskiy, Vitaliy V.; Ermolina, I. Hydrogels have attracted considerable attention due to numerous applications, in particular as contact lenses and carriers for sustained drug delivery. The aim of the present work is to characterize the interactions of copolymer hydrogels consisted of 2-hydroxyethylmethacrylate (HEMA) and 2-hydroxyethylacrylate (HEA) with a small protein (lysozyme) and to assess the potential applications of these hydrogels as a drug delivery system for sustained release of protein-based therapeutics. Physicochemical properties of protein-loaded hydrogels, as well as lysozyme in vitro loading and release and the conformation of the protein released from hydrogels were studied. The effect of copolymer composition on the protein deposition on hydrogels and protein aggregation in the presence of hydrogels was also assessed. The results show that introduction of HEA into the copolymeric hydrogels enhances their suitability as a delivery system for proteins. Copolymerisation of HEMA and HEA allows controlling the physicochemical properties of hydrogels and the protein release rate. 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.
  • Process Understanding in Freeze-Drying Cycle Development: Applications for Through-Vial Impedance Spectroscopy (TVIS) in Mini-pilot Studies
    Process Understanding in Freeze-Drying Cycle Development: Applications for Through-Vial Impedance Spectroscopy (TVIS) in Mini-pilot Studies Smith, Geoff; Arshad, Muhammad Sohail; Polygalov, E.; Ermolina, I.; McCoy, Timothy R.; Matejtschuk, Paul 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.

Click here for 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

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