Chitosan-carboxymethyl tara gum polyelectrolyte complex matrix tablets for sustained gastrointestinal drug...

Natural polysaccharides are extensively used for delivery of bioactives because of its eco-friendly, biocompatible and biodegradable characteristics. However, substantial swelling and poor rheological characteristics limits its applications as drug carriers for sustained delivery.

Chitosan (CTS) and carboxymethyl tara gum (CMTG) matrix tablets were unable provide sustained drug dissolution owing to substantial swelling and low viscosity of the matrix. The present research embarks on the development of CTS and CMTG polyelectrolyte complex (PEC) matrix tablets for sustained gastrointestinal drug dissolution.

PECs of CTS and CMTG were prepared by one shot addition method. The formation of the PECs was optimized in terms of % yield, FTIR, turbidity analysis, zeta potential, viscosity, and swelling studies. The PEC matrix tablets were prepared by wet granulation method.

At a fixed concentration of CMTG, increasing CTS concentration led to the formation of non-stoichiometric PECs with reduced % yield and poor mechanical strength making it unsuitable for tableting. At a fixed concentration of CTS, progressive increase in the concentration of CMTG resulted in the formation of stoichiometric PECs which improved the % yield and viscosity, lowered swelling index and had sufficient mechanical strength to be tableted. PEC matrix tablet F7 prepared with optimized PEC 7 (ratio between CTS and CMTG 1:3) released only 40% drug after 12 h of dissolution.

Pending validation through in vivo and stability studies, we conclude that CTS- CMTG PEC matrix tablets can be a suitable matrix material for sustained gastrointestinal drug dissolution.