Search

Clozapine (CLZ) has retained its clinical utility in the management of schizophrenia despite the discovery of novel antipsychotics, as it possesses unique efficacy in the setting of treatment resistant schizophrenia while causing minimal extrapyramidal symptoms. However, these benefits are offset by the risk of agranulocytosis and other side effects, and therapeutic drug monitoring (TDM) is routinely recommended for patients undergoing treatment with CLZ. A multitude of approaches for the quantification of CLZ have been developed for different settings such as TDM, quality control of pharmaceutical dosage forms, and toxicology studies. Primarily, these approaches fall under one of three branches of analysis, namely, chromatography, electrochemical analysis, and spectrophotometry. This study provides a scoping review of the recent advances in the methods of quantification for CLZ and highlights the potential utility of novel methods in the field of drug quantification.

Cassia alata, a traditional herb with a global presence, is renowned for its anti-inflammatory, antibacterial, and antifungal properties, making it a go-to remedy for skin ailments. While it has demonstrated wound healing capabilities in both in vitro and in vivo studies, the precise mechanisms remain elusive. This review aims to highlight its key phytochemicals, their effects, and the mechanism of action. The compounds that have been reviewed and discussed include kaempferol, apigenin, quercetin, rhein, and rutin. These polyphenols play important roles in normal and impaired wound healing processes, encompassing hemostasis, inflammation, proliferation, and tissue remodeling. [ABSTRACT FROM AUTHOR]

Atopic dermatitis (AD) is an inflamed skin condition with relapsing pruritus and cutaneous physiological dysfunction. This skin disorder is widespread around the world and frequently affects infants, children and adults. Natural products with bioactive lead compounds are the source of natural medicines for complementary and alternative therapy in managing AD. Cassia alata has been used traditionally as a remedy for a variety of health issues. In Asian countries, it is used as an ethnomedicine to treat skin conditions such pityriasis versicolor, ringworm, scabies, shingles, urticaria and itching. According to previously published studies, the phytochemicals in C. alata may have a wide range of significant pharmacological effects. AD management is highlighted here, as this review explores the literature on the pharmacological effects of C. alata and its phytochemical content. Specifically, antibacterial, wound healing, anti-inflammatory and antioxidant effects are reviewed and discussed in relation to AD management. [ABSTRACT FROM AUTHOR]

The study aims to develop and validate HPLC and UV-visible spectroscopy methods for the determination of Thymoquinone (TMQ) content in different solvent extracts of N.sativa L. seed. Evaluation of free radical scavenging effect of different solvent extracts of TMQ was investigated. Extraction of solvent was done by adding 20 ml of the following solvent (hexane, methanol, ethanol, ethyl acetate and water) to one gram of blackseed and in a conical flask, respectively. The mixtures were then incubated on a water bath at 40 oC for 2 and 4 hours, respectively. The mixtures were then centrifuged at 4000 rpm for 10 minutes at 4 oC. The extracts were then quantitatively analyzed using HPLC and UV-visible spectrophotometry. The free radical scavenging activity of TMQ extracts was studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The results obtained from HPLC indicate that TMQ extracted using hexane at 4 hours (0.075 mg/ml, p < 0.05) was significantly higher compared to other extraction solvents used. The results obtained from UV-vis spectroscopy analysis indicate that the methanol extract at 4 hours (0.00957 mg/ml, p < 0.05) was significantly higher compared to other extraction solvents used. Methanol extracts at 2 hours showed the highest free radical scavenging activity (95.8 %) compared to other extraction solvents. The results obtained show that hexane extracted the most TMQ at 4 hours. Methanol extract demonstrated the highest free radical scavenging activity. [ABSTRACT FROM AUTHOR]

Nigella sativa L., commonly known as black seed, grows natively in the Mediterranean region and Western Asian countries. Nigella sativa L. seeds extracts have diverse medicinal properties. The main active constituent, thymoquinone is medicinally very effective against various health-related issues. The objective of this study was to investigate the effects of different extraction methods and solvents on the content of thymoquinone using HPLC. One gram each of powdered black seed was extracted with 20 mL of hexane, ethyl acetate, methanol, ethanol, and water. The mixture was incubated at 4°C in water bath for 2 hours and 4 hours, respectively. The extraction was repeated for hexane and methanol by maceration, percolation, and ultrasonic assisted extraction (UAE). The extracts were centrifuge at 4000 rpm at 4°C for 10 min and filtered. The extracts were then top-up to 20 mL with the respective solvent and analyzed by HPLC. The results in the present study showed that hexane extract by maceration method is the best method to extract the main bioactive component, thymoquinone from N. sativa L. seed. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of different extraction methods on the content of thymoquinone using HPLC and UV-Vis spectroscopy. To investigate the antioxidant activities of thymoquinone by measuring the free radical scavenging activity. To identify the functional groups of thymoquinone using FTIR analysis. One gram of powdered black seed was added to 20 mL of solvents (hexane and methanol) into a conical flask and mixed. The mixtures were extracted by different methods which were maceration, percolation, and ultrasonic-assisted extraction. In the percolation method, the mixtures were placed in a water bath of 40 °C for 4 hours whereas, for maceration, the mixtures were left at room temperature for 4 hours. On the other hand, the mixtures were placed in an ultrasonic bath at room temperature for 2 hours in ultrasonic-assisted extraction. The extracts were centrifuged at 4000 rpm at 4 °C for 10 minutes and filtered. The extracts were then analyzed qualitatively and quantitatively by a validated method which was HPLC and UV-Vis spectroscopy. The standard thymoquinone was scanned to identify the functional groups present in the chemical structure. On the other hand, the antioxidant activity was measured by DPPH radical scavenging. In HPLC analysis, the maceration method with hexane extracted the most content (1.5299mg) of thymoquinone. On the other hand, in the UV method, the percolation method with methanol extracted the most content (9.1019mg) of thymoquinone. The free radical scavenging activity was observed highest (95.6891%) in methanol extracts from the percolation method. The results in the present study show that hexane extract from the maceration method is the best method to extract the main bioactive component, thymoquinone from N. sativa L. seed. Furthermore, the N. sativa seed extracts exhibit antioxidant activity. [ABSTRACT FROM AUTHOR]

Hypertension is one of the most prevalent non-communicable diseases in the Malaysian population. In addition, it is associated with various mood and psychiatric disorders such as schizophrenia. Recent studies have shown that hypertension leads to worse clinical outcomes in psychiatric patients. Diverse psychosocial factors caused by schizophrenia also impact hypertension and its clinical care. Clozapine and amlodipine are the hallmark drugs for the treatment of schizophrenia and hypertension, respectively. To date, there is no analytical assay that can simultaneously determine the concentrations of these two drugs in human matrices. An Aquasil C18 column was used in the analysis, with the mobile phase consisting of acetonitrile:water (40:60 v/v) adjusted to pH 4.5 with phosphate buffer. Detection with UV spectrometer was done at 240nm. The method was validated according to the International Council for Harmonization (ICH) guidelines. The calibration curves of clozapine and amlodipine were linear in the range of 100-600 ng/mL and 2-12 ng/mL, respectively (r2>0.99). Clozapine limit of detection (LOD) and limit of quantification (LOQ) were 129.5 ng/mL and 392.4 ng/mL, respectively. Meanwhile, amlodipine achieved LOD of 0.25 ng/mL, and LOQ of 0.75 ng/mL. Overall, the study describes quick, precise and sensitive HPLC-UV method for the simultaneous determination of clozapine and amlodipine in human plasma. [ABSTRACT FROM AUTHOR]

The oxidative properties of sunflower oil supplemented with rambutan extract, (crude extract and its fractionated fraction, SF II) in comparison with synthetic antioxidant were investigated. The supplemented sunflower oils were stored under accelerated conditions for 24 days at 60 °C. For every 6-day interval, the oxidative properties of the supplemented sunflower oil were evaluated based on the following tests, namely peroxide value, p-anisidine value, Thiobarbituric Acid Reactive Substances (TBARS) assay, iodine value and free fatty acids. The total oxidation (TOTOX) values were also calculated based on the peroxide values and p-anisidine values. Rambutan extract is a potential source of antioxidant. The oxidative activities of the extracts at all concentrations were significantly (p < 0.05) higher than the control. Generally, the partially fractionated fraction was more effective than the crude extract. With a 2-year storage period at ambient temperature, the fractionated fraction of the extract, SF II at 300 ppm, was observed to work more effectively than the synthetic antioxidant, t-Tocopherol, and it possessed a protective effect comparable with butylatedhydrioxynanisole (BHA). Therefore, rambutan extract could be used as a potential alternative source of antioxidant in the oil industry or other fat-based products to delay lipid oxidation.