Characterisation of protein stability in rod-insert vaginal rings

Aditya Pattani, Deborah Lowry, Rhonda M. Curran, Stephanie McGrath, Vicky L. Kett, Gavin P. Andrews, R. Karl Malcolm

Research output: Contribution to journalArticle

Abstract

A major goal in vaccine development is elimination of the 'cold chain', the transport and storage system for maintenance and distribution of the vaccine product. This is particularly pertinent to liquid formulation of vaccines. We have previously described the rod-insert vaginal ring (RiR) device, comprising an elastomeric body into which are inserted lyophilised, rod-shaped, solid drug dosage forms, and having potential for sustained mucosal delivery of biomacromolecules, such as HIV envelope protein-based vaccine candidates. Given the solid, lyophilised nature of these insert dosage forms, we hypothesised that antigen stability may be significantly increased compared with more conventional solubilised vaginal gel format. In this study, we prepared and tested vaginal ring devices fitted with lyophilised rod inserts containing the model antigen bovine serum albumin (BSA). Both the RiRs and the gels that were freeze-dried to prepare the inserts were evaluated for BSA stability using PAGE, turbidimetry, microbial load, MALDI-TOF and qualitative precipitate solubility measurements. When stored at 4°C, but not when stored at 40°C/75% RH, the RiR formulation offered protection against structural and conformational changes to BSA. The insert also retained matrix integrity and release characteristics. The results demonstrate that lypophilised gels can provide relative protection against degradation at lower temperatures compared to semi-solid gels. The major mechanism of degradation at 40°C/75% RH was shown to be protein aggregation. Finally, in a preliminary study, we found that addition of trehalose to the formulation significantly reduces the rate of BSA degradation compared to the original formulation when stored at 40°C/75% RH. Establishing the mechanism of degradation, and finding that degradation is decelerated in the presence of trehalose, will help inform further development of RiRs specifically and polymer based freeze-dried systems in general.
Original languageEnglish
Pages (from-to)89-97
Number of pages9
JournalInternational Journal of Pharmaceutics
Volume430
Issue number1-2
Early online date2 Apr 2012
DOIs
Publication statusPublished - 1 Jul 2012

Fingerprint

Female Contraceptive Devices
Protein Stability
Bovine Serum Albumin
Vaccines
Trehalose
Gels
Dosage Forms
Foams and Jellies Vaginal Creams
Nephelometry and Turbidimetry
Human Immunodeficiency Virus Proteins
Antigens
Equipment and Supplies
Refrigeration
Matrix-Assisted Laser Desorption-Ionization Mass Spectrometry
Solubility
Polymers
Maintenance
Temperature
Pharmaceutical Preparations
Proteins

Keywords

  • protein stability
  • vaginal delivery
  • vaginal ring
  • protein aggregation
  • freeze-dried potein

Cite this

Pattani, A., Lowry, D., Curran, R. M., McGrath, S., Kett, V. L., Andrews, G. P., & Malcolm, R. K. (2012). Characterisation of protein stability in rod-insert vaginal rings. International Journal of Pharmaceutics, 430(1-2), 89-97. https://doi.org/10.1016/j.ijpharm.2012.03.036
Pattani, Aditya ; Lowry, Deborah ; Curran, Rhonda M. ; McGrath, Stephanie ; Kett, Vicky L. ; Andrews, Gavin P. ; Malcolm, R. Karl. / Characterisation of protein stability in rod-insert vaginal rings. In: International Journal of Pharmaceutics. 2012 ; Vol. 430, No. 1-2. pp. 89-97.
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Pattani, A, Lowry, D, Curran, RM, McGrath, S, Kett, VL, Andrews, GP & Malcolm, RK 2012, 'Characterisation of protein stability in rod-insert vaginal rings', International Journal of Pharmaceutics, vol. 430, no. 1-2, pp. 89-97. https://doi.org/10.1016/j.ijpharm.2012.03.036

Characterisation of protein stability in rod-insert vaginal rings. / Pattani, Aditya; Lowry, Deborah; Curran, Rhonda M.; McGrath, Stephanie; Kett, Vicky L.; Andrews, Gavin P.; Malcolm, R. Karl.

In: International Journal of Pharmaceutics, Vol. 430, No. 1-2, 01.07.2012, p. 89-97.

Research output: Contribution to journalArticle

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Pattani A, Lowry D, Curran RM, McGrath S, Kett VL, Andrews GP et al. Characterisation of protein stability in rod-insert vaginal rings. International Journal of Pharmaceutics. 2012 Jul 1;430(1-2):89-97. https://doi.org/10.1016/j.ijpharm.2012.03.036