Formulation and In-Vivo Study of Diltiazem Hydrochloride Tablets Prepared Using Interpolymer Complexes
Abd EL – Gawad H. Abd EL – Gawad
Department of Pharmaceutics, Faculty of Pharmacy, Mansoura University, 35516, Mansoura, Egypt.
Esmail M. Ramadan
Department of Pharmaceutics, Faculty of Pharmacy, Mansoura University, 35516, Mansoura, Egypt.
Osama A. Soliman
Department of Pharmaceutics, Faculty of Pharmacy, Mansoura University, 35516, Mansoura, Egypt.
Rehab M. Yusif *
Department of Pharmaceutics, Faculty of Pharmacy, Mansoura University, 35516, Mansoura, Egypt.
*Author to whom correspondence should be addressed.
Abstract
Aim: To investigate interpolymer complexes (IPCs) formation between carbopol and cationic polymers such as chitosan and Eudragit E for oral controlled drug delivery systems.
Methodology: The prepared IPCs were investigated using Fourier transform infra-red spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Chitosan-carbopol and Eudragit E-carbopol IPCs loaded with diltiazem hydrochloride (DTZ HCl) with different drug:polymer ratios were also prepared. Diltiazem hydrochloride tablets were prepared using polymers alone, physical mixtures of chitosan or Eudragit E with carbopol and the corresponding drug loaded IPCs. In-vitro release studies were carried out in two dissolution media; 0.1 NHCl of pH 1.2 and phosphate buffer of pH 7.4.
Results: The dissolution rate of DTZ HCl from the prepared tablets were found to be dependant on the interaction between chitosan or Eudragit E with carbopol in the physical mixture, drug:polymer ratio and pH of the dissolution medium. Tablets prepared using chitosan – carbopol IPC, Eudragit E – carbopol IPC, and Eudragit E – carbopol physical mixture of drug:polymer ratio 1:5 were selected for the in-vivo study using rabbits. The results showed a lower peak plasma concentration and marked prolonged release effect of tablets containing Eudragit E – carbopol IPC and the corresponding physical mixture compared to that of commercial Altiazem tablets.
Conclusion: Tablets containing Eudragit E – carbopol or chitosan – carbopol physical mixtures showed prolonged drug release compared to that containing the corresponding IPCs, Furthermore, Eudragit E- carbopol matrix tablets showed slower drug release than that of chitosan – carbopol.
Keywords: Chitosan, Eudragit E, Carbopol, diltiazem hydrochloride, interpolymer complex, tablets.