The present study provides a detailed comparative evaluation of the stability of Nano formulations containing Carvedilol and Berberine, with emphasis on quantitative performance under different storage conditions. The optimized Nano formulations exhibited a mean particle size of 145.2 ± 2.6 nm for carvedilol-loaded nanoparticles and 152.8 ± 3.1 nm for berberine-loaded nanoparticles, while the co-loaded Nano formulation showed a slightly increased size of 160.4 ± 2.9 nm, indicating uniform Nano scale distribution. The zeta potential values were found to be −28.6 ± 1.4 mV (carvedilol), −30.2 ± 1.6 mV (berberine), and −32.5 ± 1.3 mV (combined), suggesting strong electrostatic stabilization and reduced aggregation tendency. Entrapment efficiency was significantly higher in the co-loaded system (85.7 ± 2.0%) compared to individual formulations (78.5 ± 2.2% for carvedilol and 81.3 ± 2.5% for berberine), reflecting improved drug incorporation within the Nano carrier matrix. Stability studies were carried out over a period of 90 days under both intermediate (25°C ± 2°C/60% RH) and accelerated (40°C ± 2°C/75% RH) conditions. The results indicated that all formulations maintained good stability; however, the co-loaded Nano formulation demonstrated superior performance. Particle size showed only a marginal increase of 3.2% in the combined system, compared to 4.8% and 4.5% in carvedilol and berberine formulations, respectively. Drug content remained above 95% in all cases, with the co-loaded formulation retaining 97.2% of its initial drug concentration, whereas individual formulations retained 95.5% (carvedilol) and 95.9% (berberine). Furthermore, the percentage drug degradation was lowest in the combined system (2.8%) compared to 4.5% and 4.1% observed for carvedilol and berberine Nano formulations, respectively. These findings suggest that the co-encapsulation of carvedilol and berberine within a single Nano formulation not only enhances entrapment efficiency but also improves resistance to environmental stress factors such as temperature and humidity. The improved stability can be attributed to the protective effect of the Nano carrier system and possible intermolecular interactions between the drugs, which reduce degradation pathways. Overall, the study confirms that co-loaded Nano formulations offer a more stable and efficient drug delivery system, potentially leading to enhanced therapeutic efficacy, improved patient compliance, and extended shelf life compared to conventional and single-drug Nano formulations.
Shubham Singh1*, Pradeep Kumar Yadav2, A. K. Singhai3 (Fri,) studied this question.