Formulation and evaluation of diclofenac sodium using hydrophilic matrices

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems
• Polymer Science

Background:

• Diclofenac sodium is a widely used nonsteroidal anti-inflammatory drug (NSAID).
• Achieving controlled and zero-order drug release is crucial for improving therapeutic efficacy and patient compliance.
• Hydrophilic polymers are commonly employed in formulating sustained-release dosage forms.

Purpose of the Study:

• To develop controlled-release tablets of diclofenac sodium with near zero-order release kinetics.
• To investigate the effect of hydrophilic polymers (HPMC, NaCMC, Carbopol 934) on drug release profiles.
• To evaluate the in vitro and in vivo performance of the developed formulations.

Main Methods:

• Preparation of diclofenac sodium controlled-release tablets using hydroxypropylmethylcellulose (HPMC), sodium carboxymethylcellulose (NaCMC), and Carbopol 934.
• Optimization of the drug to polymer ratio, with the optimal ratio found to be 1:2:1 (drug:HPMC:NaCMC).
• In vitro drug release studies and in vivo bioavailability assessments, including comparison with marketed products.

Main Results:

• A combination of nonionic HPMC and anionic NaCMC polymers resulted in near zero-order release of diclofenac sodium.
• Increased polymer content led to a more sustained drug release effect.
• Formulation 4 (1:2:1 drug:HPMC:NaCMC) exhibited similar bioavailability to Dicloran SR and superior bioavailability compared to Voveran SR, with statistically significant differences observed.

Conclusions:

• Controlled-release tablets of diclofenac sodium with near zero-order release can be successfully formulated using a combination of HPMC and NaCMC.
• The optimized formulation demonstrates favorable bioavailability and good in vitro-in vivo correlation.
• This study provides a promising approach for developing effective diclofenac sodium sustained-release formulations.