Development and validation of a reversed-phase HPLC method for quantification of 1'-acetoxychavicol acetate content in a nanostructured lipid carrier formulation

Abstract 1'-acetoxychavicol acetate (ACA)-loaded nanostructured lipid carriers (NLCs) were formulated for prostate cancer therapy and to determine the optimal therapeutic dose, we developed a rapid, specific, and accurate reversed-phase high-performance liquid chromatography (RP-HPLC) method to quantify the ACA content in NLCs. The method was validated according to International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. Chromatographic separation of ACA from the lipid components was performed with an Agilent 1220 Infinity LC system and ultraviolet detector using an Agilent Poroshell C18 column (4.6 x 250.0 mm). The mobile phase consisted of acetonitrile and water (80:20 [v/v]) with a flow rate of 0.8 mL/min in isocratic mode. Linearity of the standard curve was assessed at an ACA concentration range of 5-200 µg/mL, and a 1/x weighted linear regression was adopted for the calibration curve. The calculated limits of detection and quantification were 0.59 µg/mL and 1.79 µg/mL, respectively. The mean percent recovery of ACA was 100.02% (relative SD, 2%), and the coefficients of variation for intraday and interday assays were within the values required by the ICH. We also demonstrated robustness of the method by altering the mobile phase ratio and flow rate. Furthermore, we proved specificity of the method for ACA by comparing chromatograms of the blank NLC and ACA-NLC. Hence, we effectively used this validated method to determine the drug-loading capacity and entrapment efficiency of the NLCs.

Effects of reducing postprandial hyperglycemia and metabolism of acetate wheat starch on healthy mice

Abstract Recently, the acetate wheat starch (AWS) has been prepared by acetylation with an acetyl content of 2.42%, containing of rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) with 25.0%; 22.9% and 34.5%, respectively. In this study, this kind of starch was continuously evaluated with the postprandial blood glucose response and determined short-chain fatty acids (SCFAs) metabolized from AWS in the gastrointestinal tract of healthy mice by HPLC. The result showed that the mice fed with AWS exhibited a very limited increase in blood glucose level and remained stable for 2 hours after meals efficiently comparing with the control group fed with natural wheat starch (NWS). Simultaneously, the content of SCFAs produced in the caecum of the mice fed with AWS was significantly higher than mice fed with NWS, especially with acetic and propionic acids by 28% and 26%, respectively. Thus, AWS has shown to limit the postprandial hyperglycemia in mice effectively through the resistance to amylase hydrolysis in the small intestine. When going into the caecum, it is fermented to form SCFAs providing a part of energy for the body's activities, avoiding rotten fermentation causing digestive disorders which are inherent restrictions of normal high cellulose and fiber food.

Comparator product issues for biowaiver implementation: the case of Fluconazole

The aim of this work was to assess if the commercially available Fluconazole drug products (Reference, Generic and Similar) would meet the biowaiver criteria from Food and Drug Administration (FDA) and Brazilian Agency for Health Surveillance (ANVISA) agencies. All formulations were evaluated considering the dissolution profile carried out in Simulated Gastric Fluid (SGF) pH 1.2, Acetate Buffer (AB) pH 4.5 and Simulated Intestinal Fluid (SIF) pH 6.8. The results demonstrated that all formulations fulfilled the 85% of drug dissolved at 30 min criterion in SGF pH 1.2. However, in AB pH 4.5 and SIF pH 6.8, some formulations, including the comparator, did not achieve this dissolution percentage. The discrepant dissolution profiles also failed the ƒ2 similarity factor analysis, since none of the formulations showed values between 50 and 100 in the three dissolution media. Comparative dissolution profiles were not similar, considering that the main issues concerning the dissolution were evidenced for the comparator product. Hence, a revision in the regulatory norms in order to establish criteria to switch the comparator could result in an increased application of drugs based on biowaiver criteria

Spectrophotometric determination of acid dissociation constants of some arylpropionic acids and arylacetic acids in acetonitrile-water binary mixtures at 25ºC

Abstract The acid dissociation constant of drug active compounds (arylpropionic and aryl acetic acids) were determined in acetonitrile and water binary mixtures (corresponding volume fractions of 0.40, 0.45, 0.50, and 0.55) by using a multi-wavelength spectrophotometric method. Drug active compounds, which were slightly soluble in water, were studied in these binary mixtures. The dissociation constants of drug active compounds are important in drug design studies and in any research of the biopharmaceutical and physicochemical properties of drugs. The STAR program was used for the determination of dissociation constants. The acidity constants of arylpropionic and aryl acetic acids were correlated with the Kamlet and Taft solvaatochromic parameters. Aqueous pKa values of these arylpropionic and aryl acetic acids were determined from pKa values obtained from acetonitrile and water binary mixtures with varying volume fractions. The studied drugs had a pKa value corresponding to base functional group. Results showed that the acid dissociation constant values of the drug active compounds increased with an increase in acetonitrile content in the medium.

Chemical evaluation and anticholinesterase activity of Hippeastrum puniceum (Lam. ) Kuntz bulbs (Amaryllidaceae)

Hippeastrum puniceum is a species that belongs to the Amaryllidaceae family. A particular characteristic of this family is the consistent and very specific presence of isoquinoline alkaloids, which have demonstrated a wide range of biological activities such as antioxidant, antiviral, antifungal, antiparasitic, and acetylcholinesterase inhibitory activity, among others. In the present work, fifteen alkaloids were identified from the bulbs of Hippeastrum puniceum (Lam.) Kuntz using a GC-MS approach. The alkaloids 9-O-demethyllycoramine, 9-demethyl-2α-hydroxyhomolycorine, lycorine and tazettine were isolated through chromatographic techniques. The typical Amaryllidaceae alkaloids lycorine and tazettine, along with the crude and ethyl acetate extract from bulbs of the species were evaluated for their inhibitory potential on α-amylase, α-glucosidase, tyrosinase and acetylcholinesterase activity. Although no significant inhibition activity was observed against α-amylase, α-glucosidase and tyrosinase from the tested samples, the crude and ethyl acetate extracts showed remarkable acetylcholinesterase inhibitory activity. The biological activity results that correlated to the alkaloid chemical profile by GC-MS are discussed herein. Therefore, this study contributed to the knowledge of the chemical and biological properties of Hippeastrum puniceum (Lam.) and can subsidize future studies of this species