Experimental Investigation of Moisture Sorption Isotherms for Mefenamic Acid Tablets


  • Maha Muhyi Alhussaini Chemical Engineering Department, College of Engineering, University of Baghdad, Baghdad, Iraq
  • Hassanain A. Hassan Chemical Engineering Department, College of Engineering, University of Baghdad, Baghdad, Iraq
  • Nada S. Ahmedzeki Chemical Engineering and Petroleum Industry Department, Al-Mustaqbal University College, Iraq




Sorption isotherms, Equilibrium moisture content, relative humidity, water activity, Mathematical modeling, Mefenamic acid.


   The moisture sorption isotherms of Mefenamic acid tablets were investigated by measuring the experimental equilibrium moisture content (EMC) using the static method of saturated salt solutions at three temperatures (25, 35, and 45°C) and water activity range from 0.056 to 0.8434. The results showed that EMC increased when relative humidity increased and the sorption capacity decreased, the tablets became less hygroscopic and more stable when the temperature increased at constant water activity. The sorption curves had a sigmoid shape, type II according to Brunauer’s classification. The hysteresis effect was significant along with the whole sorption process. The results were fitted to three models: Oswin, Smith, and Guggenhein - Anderson and de Boer. According to the fitting results, the GAB model was the most appropriate model to describe the sorption behavior of Mefenamic acid; it had a regression coefficient range (0.9803-0.994), %E (0.69-4.06), and low values of SEE (0.85-2.2). The monolayer moisture content was calculated using the GAB model and it was concluded that the tablets should be stored at moisture content equal or slightly higher than (0.2046, 0.1843, and 0.1437 %) for desorption and (0.2073, 0.1269, and 0.1452 %) for adsorption for the three temperatures.


Toshkov N., Simitchiev A., Nenov V. , Panchev I. ,"Effect of the quantity of cocoa shells and moisture content on sorption characteristics of Extrudates from corn semolina", Scientific Works of University of Food Technologies , Vol. 66, No.1, 2020.

Z. Abdulrazak N., “Sorption of Nitrate Salts from Wastewater without and with Modification Orange Peel”, ijcpe, vol. 17, no. 3, pp. 109-116, Sep. 2016.

Ammar S. A., Muthana J.A.,Teeba M.D.," Adsorption of Fluoroquinolones Antibiotics on Activated Carbon by K2CO3 with Microwave Assisted Activation", IJCPE, Vol.17,No.2,15-23,2016.

Singh A.K., Kumari N., "Moisture Sorption Isotherm Characteristics of Ground Flaxseed". J. Food Process Technology, Vol. 5, No. 4, 2014.

Tontul S.A. ," Moisture sorption isotherm, is-steric heat and adsorption surface area of whole chia seeds", LWT - Food Science and Technology, November, 2020.

LODREDD Y.A., HERNANDEZ A.R., VELAZQUEZ1 G., "Modeling the effect of Temperature on The Water Sorption Isotherms of Chitosan Films Rocio , Food Science and Technology, Vol.37,No.1, 112-118, , 2017.

Ahmed W., Aziz M.G. , and Islam N. ,"Modeling of Moisture Adsorption Isotherm of Selected Commercial flours of Bangladesh", The Agriculturists ,Vol. 16,No.2, 35-42 ,2018.

Nakagawa H., Oyama T. ," Molecular Basis of Water Activity in Glycerol-water Mixtures ,Physical Chemistry and Chemical Physics, Vol.7 ,Article 731,Nov.,2019.

Gálvez A., López J., Kong Ah-Hen K., "Thermodynamic Properties, Sorption Isotherms and Glass Transition Temperature of Cape Gooseberry", Food Technol. Biotechnol , Vol.52 , No.1 83–92 , 2014.

Rahman M., Shyams S., Labuza T.P., ”Measurement of Water Activity Using Isopiestic Method “,Current Protocols in Food Analytical Chemistry, 2000 .

Esquijarosa J.A., Haza U.J. and LeRoux G.C. ,"Behavior and Modeling of Humidity Isotherm of Mangifera Indica L(Vimang) Powder",World Applied Sciences Journal,Vol.11, No.12, pp 1504-1509,2010.

Lagoudaki M.,Demertzis P.G. ,"Equilibrium Moisture Characteristics of Food-Hysteris Effect and Isotherm Models",Lebensmittel Technologie ,Vol.26,No.4,1993.

Alwan M.M., "Equilibrium Moisture Sorption Isotherms of Aspirin", Journal of Engineering, Vol.19, No.4, 2013.

Ethmane C.S., Kane E., Kouhila M., Lamharrar A., A. Idlimam and Lamharrar A.," Moisture sorption isotherms and thermodynamic properties of tow mints: Mentha pulegium and Mentha rotundifolia", Revue des Energies Renouvelables Vol. 11 No.2 ,pp. 181 – 195,2008.

Zeymer J.S., Corrêa P.C. , Oliveira G.H. , Baptestini F.M. , Campos R.C.,"Mathematical Modeling and Hysteresis of Sorption Isotherms for Paddy Rice Grains", Eng. Agríc., vol.39, No.4, July/Aug, 2019.

Hawa L.C., Aini K.N., Maharani D. M. and SusiloB., "Moisture Sorption Isotherm and Isosteric Heat of Dried Cabya ( Piper retrofractum Vahl) Powder", International Conference of Sustainability Agriculture and Biosystem,2020.

Bell L. N., Labuza T. P.," Determination of moisture sorption isotherms. Moisture Sorption: Practical Aspects of Isotherm Measurement and Use, The American Association of Cereal Chemists, “2nd Edition, AACC Egan Press., 33-56, 2000.

Yanxia L., Yeshwant D. and Yisheng C. , "A Study on Moisture Isotherms of Formulations: the Use of Polynomial Equations to Predict the Moisture Isotherms of Tablet Products, Pharm Science Tech. Vol. 4 ,No. 59, 2003.

Robert L. Hassel, Moisture Sorption Analysis of Pharmaceuticals, TA INSTRUMENTS USA, 2016.

Bennamoun L., Tagne M.S. and Ndukwu M.C.," Simulation of Storage Conditions of Mixed Biomass Pellets for Bioenergy Generation: Study of the Thermodynamic Properties, Energies, Vol.13, 2544, 14 pages, 2020.

Mania P., Majka J., Zborowska M., "The Effect of Thermo-Mechanical Treatment of Moso Bamboo Phyllostachys Pubescens) on Its Sorption and Physicomechanical Properties" , DRVNA INDUSTRIJA Vol.3, No.70, 265-272 ,2019.

Baptestini F. M. , Corrêa3 P.C. , Ramos A.M. , Junqueira M.S. and Zaidan I.R., "GAB model and the thermodynamic properties of moisture sorption in soursop fruit powder, Rev. Ciênc. Agron., v. 51, No. 1, 2020.

Vasilea F.E., Judisa M. , Mazzobre M.F," Moisture sorption properties and glass transition temperature of a nonconventional exudate gum ( Prosopis alba) from northeast Argentine", Food Research international, Vol.,No.131, 2020.

Durakova A. , Bogoeva A., Krasteva R. , "Sorption characteristics of subtropical fruit – Lucuma powder", Materials Science and Engineering, Conference, 2019.

Greenspan L.” Humidity Fixed Points of Saturated Aqueous Solutions” , Journal of Research of the National Bureau of Standards, Vol.81, No.1, pp.89-96, 1977.

Zeymer J.S. , Corrêa1 P.C. , Horta G.H. , Viana M.E. , Magalhães D.S.," Thermodynamic properties of moisture desorption isotherms of ryegrass (Lolium multiflorum L.) seeds, Ciência e Agrotecnologia, 44:e027619, 2020.

Hawa L. C., Lastriyanto A., Tambunan T. N. ," Sorption characteristics of banana slices (Musa paradisiaca L.) var. Raja Nangka by gravity method", Advances in Food Science, Sustainable Agriculture and Agroindustrial Engineering,Vol.1 ,No.1,pp. 19 – 24,2018.

Oluwamukomi M. O. , "Adsorption isotherm modeling of soy-melon-enriched and un-enriched ‘gari’ using GAB equation", African Journal of Food Science, Vol. 3No.5, pp. 117-124, May, 2009.

Alakali J., Irtwange S.V. and Satimehin A. ,"Moisture adsorption characteristics of ginger slices",Cienc Tecnol. Aliment.,Vol.29,No.1, 2009.

Blahovec J. & Yanniotis S.," GAB Generalized Equation for Sorption Phenomena", Food Bioprocess Technol. , Vol.1,pp.82–90,2008.

Gustavo V. B., Anthony J. F., Schmidt J.S. , Labuza T.P.," Water Activity in Foods: Fundamentals and Applications, Second Edition, John Wiley & Sons, Inc,2020.

Arogba S.S.," Effect of Temperature on The moisture Sorption Isotherm of a Biscuit Containing Mango Kernel Flour", Journal of Food Engineering ,Vol.,No.48 pp.121-125,2001.

Zammouri, A. , Ben Z. M. , Kechaou, N. , Mihoubi B., "Thermodynamic properties and moisture sorption isotherms of two pharmaceutical compounds ", 21st International Drying Symposium, Spain, 11-14 September, Conference Paper, 2018.

Parmar J. & Rane M. ,"Tablet Formulation Design And Manufacture: Oral Immediate Release Application", Pharma Times, Vol. 41 , No. 4 , April ,2009.




How to Cite

Alhussaini, M. M., Hassan, H. A., & Ahmedzeki, N. S. (2020). Experimental Investigation of Moisture Sorption Isotherms for Mefenamic Acid Tablets. Iraqi Journal of Chemical and Petroleum Engineering, 21(4), 11–20. https://doi.org/10.31699/IJCPE.2020.4.2