THERMODYNAMIC PROPERTIES OF OCULAR PERMEATION OF
DICLOFENAC: EFFECT OF TRIETHANOLAMINE
RAJARAM MOHAPATRA, SIBANANDA SENAPATI, CHINMAYA SAHOO, SUBRATA MALLICK*
Department of Pharmaceutics, School of Pharmaceutical Sciences, Siksha ‘O’ Anusandhan University, Khandagiri Square,
Bhubaneswar, OR, India
*corresponding author: s_mallickin@yahoo.com; profsmallick@gmail.com
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Abstract:
The objective of the present study was to evaluate the effect of triethanolamine (TEA) as plasticizer on the thermodynamic
properties of ex-vivo permeation of diclofenac potassium (DP) from hypromellose matrix films. The apparent permeability
has been evaluated at different temperatures and utilized for estimation of activation energy (Ea), enthalpy (ΔH), entropy (ΔS)
and free energy (ΔG) of permeation, diffusion and partition. Permeation was found to be increasing with the increase of
temperature and concentration of plasticizer. Improved permeation has been supported by the decreased value of activation
energy. Positive ΔH value of all the films indicated increased permeation with the increase of temperature. The presence
TEA in the formulation significantly lowered the ΔS value compared to the film without TEA. FTIR, DSC and SEM studies
of the films revealed the inhibition of the crystal growth and transformation of crystalline nature of drug to amorphous state.
The film (containing 30% TEA) was rehydrated in vivo upon lachrymal fluid uptake and progressed as a bioerodible swelled
mass at the end of 5 h of application.

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