Effect of intra- and extragranular addition of highly porous tribasic calcium phosphate on properties of immediate release acyclovir formulation – Comparison with commercial tablets using compendial and biorelevant dissolution methods

Abstract Immediate release, compositionally proportional formulations of acyclovir comprising porous tribasic calcium phosphate were developed and compared with commercial tablets. Comparison of the dissolution behavior was carried out using a compendial method, as well as with the help of a biorelevant dissolution stress test device, which simulates physiological mechanical stress occurring in the gastrointestinal tract. The results showed that the way how tribasic calcium phosphate is used (intra- or extragranular) had an impact on the mechanical properties of tablets as well as their dissolution performance. The dissolution rate of acyclovir from the developed formulations was fast and similar to marketed formulations.