Bioavailability studies.

The study was aimed to formulate solid dispersions of Manidipine by using different novel carriers like Labrafac PG, Kolliwax RH 40, Soluplus, Kolliwax GMS II, Kolliphor EL and SLS in drug carrier ratio by using solvent evaporation method. The formulations were characterized for physical appearance, solubility and in vitro dissolution studies. The optimized formulation was characterized by, Formulation SD13 was found to be optimized one based on the solubility, dissolution and other parameters using Kolliwax GMS II and SLS.  The drug release of the optimized formulation was found to be 99.41±5.38% within 90min. Powder X-ray diffraction studies performed on solid dispersion showed that Manidipine existed in the amorphous form within the solid dispersion formulation fabricated using the solvent evaporation process. Additionally, scanning electron microscopy studies suggested the conversion of crystalline Manidipine to an amorphous form. Furthermore, the pharmacokinetic parameters of the optimized Manidipine solid dispersions showed increased AUC0–t, AUC0–∞ and Cmax by 2-folds. These results suggest that the preparation of Manidipine solid dispersions using the solvent evaporation technique without might be a promising approach for improving the oral bioavailability of Manidipine. Therefore, the solid dispersions using Kolliwax GMS II as hydrophilic carrier in the combination of SLS can be successfully used for improvement of solubility and bioavailability of Manidipine.

Nimodipine, a poorly soluble drug, was considered to be fit for solid dispersions to improve its solubility and bioavailability. Our study intended to prepare Nimodipine solid dispersions by solvent evaporation method using various novel polymers. Solubility and dissolution studies indicate that Kolliwax RH 40 and SLS is the most suitable polymer. The solubility studies were corresponded with dissolution data and the formulation SD15 was found to be having highest drug release of about 98.96±5.15% in about 90 minutes. In-vitro release data from several formulations containing XRD and SEM studies indicate no crystallinity in the optimized formulation SD15. FTIR studies suggested good drug excipient compatibility between all components of prepared formulation. From in vivo bioavailability studies, Cmax of the optimized formulation SD15 was 4.34±0.08ng /ml, was significantly higher as compared to pure drug suspension, i.e., 2.78±0.35ng/ml. Tmax of optimized formulation was decreased significantly when compared with pure drug (1.00±0.05hr, 2.00±0.01hr), AUC0-? and AUC0-t for optimized solid dispersion formulation was significantly higher (p<0.05) as compared to pure drug suspension. The present study demonstrated that formulation of Nimodipine solid dispersion by solvent evaporation technique is a highly effective strategy for enhancing the bioavailability of poorly water soluble Nimodipine.

Aim of present study was to develop self emulsifying drug delivery system (SEDDS) for enhancement of solubility, dissolution rate and oral bioavailability of model drug Rilpivirine. Fifteen formulations were prepared using different oils, surfactants and co-surfactants. A pseudo ternary phase diagram was constructed to identify the self-micro emulsification region. Further, the resultant formulations were investigated for clarity, phase separation, drug content, % transmittance, globule size, freeze-thaw stability and in vitro dissolution studies. On the basis of dissolution profile and other above mentioned studies, F5 was found to be the best formulation of Rilpivirine SEDDS which contains Captex 355(Oil), Kolliphor RH 40 (Surfactant) and PG (Co-surfactant). In vivo studies revealed that the oral bioavailability of Rilpivirine from SEDDS was 2.2-fold higher compared to that of pure Rilpivirine suspension in rats, suggesting a significant increase (p