profile image for Professor Iain Cumming

Professor Iain Cumming

Head of School

Medway School of Pharmacy

 

Iain graduated from The Robert Gordon University (RGU) in 1981 and completed his pre-registration training at Aberdeen Royal Infirmary in 1982. He gained his initial pharmaceutical industry experience working for Napp Laboratories in Cambridge. Iain then had a lecturing post in pharmaceutics and drug delivery at RGU 1988-1994, where he also completed a PhD in pharmaceutics in the area of transdermal research. This was followed by a very enjoyable time at Elan Corporation, Ireland, bringing new R & D products to market and managing the science of numerous global Joint Ventures in multiple fields.

Prior to becoming Head of School at Medway in August 2007, Iain was Vice President for R & D and Quality for IVAX Europe, a major generic pharmaceutical company.

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Professor Cumming’s major research interests are focused on pharmaceutics and drug delivery systems. Particular areas include transdermal, controlled release, pulmonary, and nanoparticulate drug delivery systems and their application to pharmaceutical products. He also has an interest in the development of methods to improve bioavailability of drugs with low aqueous solubility.

Current Projects

Hydrophilic matrices are a principal technology used for extended release (ER) oral dosage forms as they make it relatively easy to achieve a desirable drug-release profile, they are cost effective, and they have broad US Food and Drug Administration acceptance. A recent review concluded that the development of sustained release formulations is currently one of the most important challenges in pharmaceutical research. The researchers recognized that the mechanisms involved in drug release from these matrix systems are complex and depend upon many factors.

Our research currently focuses in the following two areas:

Stability of Polyethylene Oxide (PEO) polymers in the manufacture of matrix tablets

PEO’s have been used throughout the 1990’s to form solid hydrophilic matrix tablets which is mainly attributed to their desirable hydration and gel formation capacity and the availability of a range of molecular weights. Research into the use of PEO’s for the manufacture of CR dosage forms has continued in the last decade. Further the dissolution and swelling behavior of the PEO’s and their mixtures with other polymers has also been investigated and the techniques for looking at gel layer behavior have been reviewed.

It is known that there can be thermal oxidation of PEO’s in the solid state and that this is an autocatalytic free radical process. It is also recognized that butylated hydroxytoluene (BHT) is added to Polyox at <0.1% to prevent oxidation. However, there is limited and sometimes potentially conflicting data available in the literature regarding the stability of these polymer systems. Recent studies have suggested that there can be stability problems resulting in changes in the dissolution profiles of manufactured tablet formulations. Our current research work investigates the stability of PEO matrix tablets containing drugs with varying solubility, as well as the addition of various diluents and added antioxidants.

Currently working on this project: Mr Saeed Shojaee PhD student (2009-).

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Impact of Polymer Particle size on drug release rate from Matrix Tablets

Hydroxypropyl methylcellulose (HPMC) or hypromellose is one of the most commonly used polymers worldwide, it has GRAS status, can be easy to use in direct compression and leads to low cost of oral dosage form manufacture. HPMC has been extensively studied for many decades and many factors affecting the production of matrix tablets as well as the subsequent release of a wide range of active ingredients was the subject of an excellent review by Li et al. (2005). The particle size of HPMC is recognised to be a critical factor in the release rate from matrix tablets. However, various different studies have provided different interpretations regarding the impact of the particle size of the polymer. We are investigating the effect of particle size of HPMC for tablets made using a range of drugs with varying aqueous solubility, we are also looking at the impact of different diluents in these systems. This work is also being extended to look at the importance of particle size for polyethylene oxide which has not been investigated previously.



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  • Shojaee, S., Emami, P., Mahmood, A., Rowaiye, Y., Dukulay, A., Kaialy, W., Cumming, I., and Nokhodchi, A. (2015). An Investigation of the effect of Polyethylene Oxide concentration and particle size in modulating Theophylline release from tablet matrices. AAPS PharmSciTech epub online.
  • Shojaee, S., Nokhodchi, A., Cumming, I., Alhalaweh, A. and Kaialy, W. (2015). Investigation of Drug Release from PEO tablet matricesin the presence of Vitamin E as antioxidant. Current Drug Delivery (12) epub online.
  • Shojaee, S., Kaialy, W., Cumming, K. I. and Nokhodchi, A. (2014). Comparative evaluation of drug release from aged prolonged polyethylene oxide tablet matrices: effect of excipient and drug type. Pharmaceutical Development and Technology epub online.
  • Shojaee, S., Nokhodchi, A., and Cumming, I. (2014). The role of fillers and sodium metabisulfite on drug release from aged polyox tablets. Drug Development and Industrial Pharmacy 40 (11) 1451-1458.
  • Shojaee, S., Cumming, I., Kaialy, W. and Nokhodchi, A. (2013). The influence of vitamin E succinate on the stability of polyethylene oxide (PEO) controlled release matrix tablets. Colloids and Surfaces B: Biointerfaces 111, 486-492.
  • Shojaee, S., Asare-Addo, K., Kaialy, W., Nokhodchi, A., and Cumming, I. (2013). An investigation into the stabilization of Diltiazem HCl release from matrices made from aged Polyox Powders. AAPS PharmSciTech 14 (3) 1190-1198.
  • Shojaee, S., Nokhodchi, A. and Cumming, K.I. (2010). Effect of ageing on release rate of diltiazem hydrochloride from Polyethylene Oxide matrix tablets prepared by direct compression. J. Pharm. Pharmacol., 62, 10, 1421-1422.
  • Cumming, I. and Khedmati, B. (2009) The effect of hydroxypropylmethylcellulose particle size on drug release rate from hydrophilic matrix tablets. J. Pharm. Pharmacol., S1, 127.

Issued Patents

  • U.S. 8,753,683. Delivery of a bioactive material. Clancy, M.J.A., Cumming, K.I. and McCrystal, C.B.: Issued 17/6/2014.
  • U.S. 8,323,690. Solid dosage form containing an enhancer. Cumming, K.I. and Ramtoola, Z. Issued 4/12/2012.
  • U.S. 8,293,277. Controlled-release nanoparticle compositions. Swanson, J., Cumming, K.I. & others. Issued 23/10/2012.
  • U.S. 8,236,352. Glipizide compositions. Bosch, H.W., Cumming, K.I. & others. Issued 7/8/2012.
  • U.S. 8,119,159. Solid dosage form containing an enhancer. Cumming, K.I., Ramtoola, Z and Leonard, T.W.: Issued 21/2/2012.
  • U.S. 8,053,429. Solid dosage form containing an enhancer. Cumming, K.I. and Ramtoola, Z. Issued 8/11/2011.
  • U.S. 7,670,626. Delivery of a bioactive material. Clancy, M.J.A., Cumming, K.I. and McCrystal, C.B.: Issued 2/3/2010.
  • U.S. 7,658,938. Solid dosage form containing an enhancer. Cumming, K.I. and Ramtoola, Z.: Issued 9/2/2010. {European equivalent EP1154761, Issued 20/2/2008.}

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Last Updated 26/11/2015