Formulation of solid dispersion to improve dissolution and oral bioavailability of poorly soluble dexibuprofen

Evaluation of microstructure, dissolution rate, and oral bioavailability of paclitaxel poloxamer 188 solid dispersion

Poor solubility is a major challenge for enhancing the oral bioavailability and clinical application of many drugs, including the broad-spectrum chemotherapy drug paclitaxel (PTX). A practical approach to improving the solubility of insoluble drugs is through the use of solid dispersion (SD). This study aimed to investigate the potential of the triblock copolymer, poloxamer 188 (P188), as a carrier for preparing solid dispersion of paclitaxel using spray drying technology. We systematically studied its microstructure, dissolution behavior in vitro, and pharmacokinetics. Our findings demonstrate that PTX exists in an amorphous state in copolymer composed of polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO-PPO-PEO) P188, with stronger miscibility with hydrophobic PPO segments. All three in vitro dissolution models revealed that the release rate of drugs in SD was significantly higher compared to that of physical mixtures (PM) as well as raw drugs. Furthermore, our pharmacokinetic results showed that the area under the curve(AUC) of PTX in SD was 6 times higher than that of active pharmaceutical ingredient(API), 4.5 times higher than PM, and the highest blood drug concentration (Cmax) reached 357.51 ± 125.54 (ng/mL), approximately 20 times higher than API. Overall, our findings demonstrate that the dissolution rate of amorphous PTX in SD significantly improves, effectively enhancing the oral bioavailability of PTX.

Preparation of amentoflavone-loaded DSPE-PEG2000 micelles with improved bioavailability and in vitro antitumor efficacy

To overcome the poor aqueous solubility and enhance the anticancer effects of amentoflavone (AF), a nontoxic and biodegradable amphiphilic copolymer, poly(ethyleneglycol)-distearoylphosphatidylethanolamine (DSPE-PEG2000 ), was introduced to prepare AF micelles using the thin-film hydration method. Amentoflavone was successfully encapsulated into the core, achieving an encapsulation efficiency of 98.80 ± 0.24% and a drug loading efficiency of 2.96 ± 0.12%. The resulting micelles exhibited a spherical shape with a particle size of approximately 25.99 nm. The solubility of AF was significant improved by 412-fold, and cumulative drug release studies showed that AF release was much faster from the micelles compared with the free drug. The release of AF was sustained over time and followed a degradation-based kinetic model, similar to polymeric systems. After oral administration, the AF-loaded micelles demonstrated an enhanced oral bioavailability, which was 3.79 times higher than that of free AF. In vitro evaluations of the micelles' antitumor effects revealed a significantly greater efficacy compared with free AF. These findings highlight the tremendous potential of DSPE-PEG2000 micelles as a drug delivery carrier for improving the solubility and therapeutic efficacy of AF.

Enhanced Solubility and Biological Activity of Dexibuprofen-Loaded Silica-Based Ternary Solid Dispersions

The current study was designed to formulate ternary solid dispersions (TSDs) of dexibuprofen (Dex) by solvent evaporation to augment the solubility and dissolution profile, in turn providing gastric protection and effective anti-inflammatory activity. Initially, nine formulations (S1 to S9) of binary solid dispersions (BSDs) were developed. Formulation S1 comprising a 1:1 weight ratio of Dex and Syloid 244FP^® was chosen as the optimum BSD formulation due to its better solubility profile. Afterward, 20 TSD formulations were developed using the optimum BSD. The formulation containing Syloid 244FP^® with 40% Gelucire 48/16^® (S18) and Poloxamer 188^® (S23) successfully enhanced the solubility by 28.23 and 38.02 times, respectively, in pH 6.8, while dissolution was increased by 1.99- and 2.01-fold during the first 5 min as compared to pure drug. The in vivo gastroprotective study in rats suggested that the average gastric lesion index was in the order of pure Dex (8.33 ± 2.02) > S1 (7 ± 1.32) > S18 (2.17 ± 1.61) > S23 (1.83 ± 1.04) > control (0). The in vivo anti-inflammatory study in rats revealed that the percentage inhibition of swelling was in the order of S23 (71.47 ± 2.16) > S18 (64.8 ± 3.79) > S1 (54.14 ± 6.78) > pure drug (18.43 ± 2.21) > control (1.18 ± 0.64) after 6 h. ELISA results further confirmed the anti-inflammatory potential of the developed formulation, where low levels of IL-6 and TNF alpha were reported for animals treated with S23. Therefore, S23 could be considered an effective formulation that not only enhanced the solubility and bioavailability but also reduced the gastric irritation of Dex.