BackgroundBerberine is an isoquinoline alkaloid widely used in Ayurveda and traditional Chinese medicine to treat illnesses such as hypertension and inflammatory conditions, and as an anticancer and hepato-protective agent. Berberine has low oral bioavailability due to poor aqueous solubility and insufficient dissolution rate, which can reduce the efficacy of drugs taken orally. In this study, evaporative precipitation of nanosuspension (EPN) and anti-solvent precipitation with a syringe pump (APSP) were used to address the problems of solubility, dissolution rate and bioavailability of berberine.MethodsSemi-crystalline nanoparticles (NPs) of 90–110 nm diameter for APSP and 65–75 nm diameter for EPN were prepared and then characterized using differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRD). Thereafter, drug content solubility and dissolution studies were undertaken. Berberine and its NPs were evaluated for their antibacterial activity.ResultsThe results indicate that the NPs have significantly increased solubility and dissolution rate due to conversion of the crystalline structure to a semi-crystalline form.ConclusionBerberine NPs produced by both APSP and EPN methods have shown promising activities against Gram-positive and Gram-negative bacteria, and yeasts, with NPs prepared through the EPN method showing superior results compared to those made with the APSP method and the unprocessed drug.

Wulfenia amherstiana belongs to the Scrophulariaceae family and various plants of this family are known for their biological activities. The present study was focused on the isolation of bioactive compounds including a novel flavone 6,7,4′-trimethyl flavone (TMF) along with three known flavonoids such as quercetin, rutin, and a steroid β-sitosterol which were isolated from the ethanolic extract of W. amherstiana (Himalayan Wulfenia) through column chromatography and purified by using HPLC. Their structures were identified and elucidated through electron ionization mass spectroscopy (EIMS), 1DNMR (1H-NMR and 13C-NMR), and 2DNMR (COSY, HMQC, and HMBC) spectroscopy. The antimicrobial activities of this novel compound were evaluated through agar well diffusion method, while antioxidant and cytotoxic activities were assessed through 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging assay and brine shrimp lethality assay, respectively. The NMR data revealed that TMF is a novel compound. TMF showed potential antibacterial and antifungal activities against Staphylococcus aureus (MIC = 128 μg/ml) and Candida albicans (MIC = 128 μg/ml). The cytotoxic potential of TMF was determined from brine shrimp lethality assay with LD50 of 127.01 μg/ml. The free-radical scavenging potential of TMF at various concentrations implicated its strong antioxidant activity in vitro. The results revealed that TMF demonstrated substantial antimicrobial activity against S. aureus and C. albicans, strong antioxidant activity, and moderately cytotoxic activity.

Intrinsic dissolution testing has been applied for characterization of pure API with respect to its dissolution behavior. The effect of formulation factors and processing parameters on dissolution rate is evaluated by dissolution testing of the final product, which is a time and resource-consuming process. Our objective was to use intrinsic dissolution testing for determining the effect of processing parameters on drug release. In the present study, an intrinsic dissolution testing method was developed for atenolol and validated according to the standard guidelines using USP-recommended dissolution media. Various experimental variables (compaction pressure and rotation speed of the disk) were optimized by studying at three levels. Atenolol was subjected to granulation in a super mixer granulator by applying standard wet granulation protocols. Granulation time and binder concentration were taken as process variables while dissolution rate was a response variable. Dissolution media had no interference with sample analysis, and all validation parameters for the developed method were in an acceptable range (%RSD > 1). The intrinsic dissolution rate of atenolol (1.84 ± 0.13 mg/cm 2 min) was high due to its better solubility in dissolution media. The dissolution rate of atenolol was decreased by granulating with PVP under different conditions. We concluded that intrinsic dissolution testing method can be applied for determining the effect of processing parameters on dissolution rate of the API at the pre-compression level. This method will reduce experimentation for optimization of dissolution rate and will spare time and resources.

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