crospovidone

The aim of this study is to develop and characterize a solidified self-emulsifying formulation of glimepiride, and to compare its in vitro drug release profile to a commercially available tablets. Several self-emulsifying formulations (SEF) were prepared by selecting different combination from constructed pseudoternary phase diagram. Selected formulations SEF1, SEF2 and SEF3 were solidified using crospovidone and evaluated. Following emulsification, the optimized formula was selected to have the smallest mean particle size and the highest absolute zeta potential, which should yield the formation of a stable emulsion and its superiority in dissolution characteristics. Particle size and distribution of SEF1, SEF2 and SEF3 were 423.36nm, 159.128nm and 115.899nm respectively. Zeta potential analysis revealed  that SEF3 had highest zeta potential – 43.78mV followed by -39.2mV (SEF2) and -39.08mV (SEF1). In vitro drug release in 30 min of formulation SEF1, SEF2 and SEF3 were 75.31%, 83.48% and 93.03% respectively. Which indicated superiority of SEF3. In vitro studies were also performed to compare the optimized formula, SEF3, to a commercially available Betaglim tablet. T50% of glimepiride in SEF3 and betaglim was found to be 7 min and 22 min respectively. Which indicated a significant improvement in glimepiride release characteristics. SEF3 was found to be stable under stressed conditions. However slightly increased globules size of sample stored at accelerated storage condition for 12 weeks was observed.

  Nimodipine is an antihypertensive, calcium channel blocker, vasodilator agent and used in the treatment of various cardiovascular disorders such as angina pectoris, cardiac arrhythmia and hypertension. Oral bioavailability of Nimodipine is around 13% and having half life 9 hrs. In present research work an attempt has been made to prepare fast dissolving tablets of Nimodipine by direct compression technique with β-cyclodextrin complexes using various superdisintegrants. The powder blends were subjected for pre-compressional parameters. The prepared tablets were evaluated for post-compressional parameters. The prepared tablets were characterized by DSC and FTIR Studies. No chemical interaction between drug and excipients was confirmed by DSC and IR studies. The values of pre-compression parameters evaluated were within prescribed limits and indicated good free flowing property. All the post-compressional parameter are evaluated were prescribed limits and results were within IP acceptable limits. The tablets were evaluated for the in-vitro disintegration time and it was observed that the time for all the formulations varied from 19.24 to 48.29 sec. The promising formulations CCP4, CCC4 and CSS1 shows the 90 % of drug released within 5-8 min. Among all the formulation CCP4 (15 % crospovidone) were found to be best and showed a disintegration time of 19.24 sec, 50 % of drug released in 0.96 min, and 90 %  of drug released in 4.78 min. The stability study was conducted as per the ICH guidelines and the formulations were found to be stable, with insignificant changes in hardness, drug content and disintegration time. These results revealed that fast dissolving tablets of the poorly soluble drug, Nimodipine, showing enhanced dissolution and, hence, better patient compliance. Key words: Fast dissolving tablets, Nimodipine, sodium starch glycolate, croscarmellose sodium, crospovidone,  β-cyclodextrin.