Five species of Croton were investigated for the essential oil obtained by hydrodistillation from aerial parts of the plants and analyzed by gas chromatography/mass spectrometry. The essential oil yields from fresh weight ranged from 0.01% to 1%. The essential oil of C. hilarii Baill. exhibited the lowest yield (0.01%). Following this, C. pycnocephalus Müll.Arg. oil yielded 0.1%, while C. gnaphalii Baill. achieved 0.2%. Conversely, C. calycireduplicatus Allem and C. cuchillae-nigrae Croizat afforded the highest yields, both reaching 1%. The essential oils from the latter two species were rich in monoterpenes (52.5% and 59.9%, respectively), being β-pinene the prevalent compound (32.8% and 40.1%, respectively). In contrast, the essential oils from C. pycnocephalus and C. gnaphalii were characterized by a substantial content of sesquiterpenes (85.7% and 79.1%, respectively), being bicyclogermacrene (26.4% and 31%) the predominant component. The C. hilarii essential oil presented only sesquiterpene in its composition, among which sesquicineole (19.90%) and epi-α-bisabolol (16.4%) were the most abundant. The species with high amount of essential oil (C. calycireduplicatus and C. cuchillae-nigrae) were subjected to supercritical fluid extraction (SFE) at a temperature of 40 °C and different pressions. The fractions were analyzed by GC-MS. The SFE demonstrated pressure-dependent selectivity for compound classes. At 80 bar, sesquiterpenes were predominantly obtained. Increasing pressure led to the progressive disappearance of lower molecular weight terpenes and extraction of triterpenes (e.g., amyrins), and hydrocarbons at higher pressures. Nevertheless, SFE yields were generally low, indicating the conditions used were not optimal for the plants in study.

Sirolimus (SRL) is an immunosuppressive macrolide widely used in transplant patients to prevent organ rejection. The development of an analytical method with adequate selectivity, sensitivity, and reliability is essential for its quality control and therapeutic monitoring. A validated analytical method for the quantification of SRL was developed using High-Performance Liquid Chromatography coupled with a Diode Array Detector (HPLC-DAD). The method demonstrated linearity for SRL in the concentration range of 10 to 80 μg.mL⁻¹ (r = 0.9999). Precision was confirmed with coefficients of variation below 2%, and accuracy showed recovery values close to 100%. The validated method was successfully applied to sugar-coated tablets, demonstrating its suitability for routine quality control. Therefore, the developed method can be reliably used for the quantitative analysis of Sirolimus in sugar-coated tablets.

The aim of this study was to develop microparticles containing levodopa and a new combination of polymers for lung delivery and evaluate the pulmonary cytotoxicity in vivo of this novel formulation. Spray-drying technique was used to produce the powders containing levodopa, chitosan, HPMC and hyaluronic acid at different proportions and conditions. In addition, a cytotoxicity assay in rats was performed to evaluate the pulmonary membrane damage. The results showed good drug loading capacity (97.30% ± 0.5) and the obtained microparticles presented appropriate aerodynamic diameter for pulmonary delivery (4.18 ± 0.09 µm). The fine particle fraction found was 25.49 % and the bronchoalveolar lavage (BAL) study in vivo showed that levodopa microparticles did not cause considerable increment on the activity of marker enzymes in relation to the untreated control group. Therefore, no respiratory tract toxicity was observed with this novel formulation. The results also present an innovative combination of polymers for lung delivery.

Chrysin is a flavonoid with many biological and medicinal activities, such as anti-cancer, anti-inflammatory, anti-diabetic,and antioxidant properties, and has medicinal value. Based on the Quality by Design approach, the present study used aUV-spectrophotometer to develop a bioanalytical method for chrysin in human plasma. The validation of the method wasperformed as per ICH M10 guidelines. The technique was performed using methanol as a solvent and the spectrum wasrecorded at a wavelength of 370 nm. The spiked chrysin from plasma was extracted using the protein precipitation method.The developed method was linear with an r2 value of 0.9996 over a concentration range of 4-20 μg/ml. The results of allvalidation parameters are found to be within the accepted limits with a % RSD value of less than 2% and the % recoverywas greater than 95%. The % RSD and % recovery results confirmed that the method was precise and accurate in the study.LOD and LOQ values in plasma samples were found to be 0.47 μg/ml and 1.43 μg/ml respectively. The stability studieslike freeze-thaw, and short-term stability studies were also performed and proved the reliability of the method. Therefore,the developed bioanalytical method can effectively estimate chrysin in plasma samples within its sensitivity limits.

This study aimed to develop and validate an analytical methodology for quantifying curcumin in soybean oil nanocapsules. The chromatography separation used a C18 column (Phenomenex, 4.6 x 150mm, 5μm) and a ternary mixture of acetonitrile, acidified water (pH 3.0), and methanol (53:42:5). The flow rate used was 1 mL.min-1, and curcumin in the samples was detected at 425 nm. The chromatographic method proved specific for curcumin quantification and linear (correlation coefficient 0.9998). The limits of detection and quantification for the curcumin were 0.2575 µg.mL-1 and 0.7804 µg.mL-1, indicating the sensitivity of the analytical method. The repeatability and intermediate precision tests showed that the process is accurate (SRD less than 2%). In addition, the accuracy test showed values close to 100% for recovery of the bioactive. Thus, a new analytical method for quantifying curcumin in soybean oil nanocapsules may be used to analyze bioactive content.

Obesity is a complex and multifactorial disease with a global prevalence that has increased in recent decades. Simultaneously, the media exerts a strong influence by imposing an ideal body standard, which intensifies the search for weight loss methods, often adopted without proper guidance. This study aimed to identify sibutramine in four weight loss products marketed as natural. For this purpose, each sample underwent liquid-liquid extraction with methanol, followed by analysis of the organic extract using gas chromatography-mass spectrometry (GC-MS). Sibutramine was detected in three of the four capsule form weight loss products analyzed. The undeclared presence of sibutramine constitutes adulteration and represents a health risk to consumers, particularly because it is a substance under special regulatory control. The findings reinforce the need for more rigorous and effective regulatory oversight to curb illegal practices in the marketing of weight loss products and protect the health of the population.

The current study aims to develop and optimize a simple, novel, reproducible and efficient RP-UHPLC and its analogous UV spectroscopic method for routine analysis of Tofacitinib Citrate (TFC). For the RP-UHPLC method, chromatographic separations were conducted using a mobile phase comprising acetonitrile and ammonium acetate buffer (55:45%, v/v) at a flow rate of 0.8 mL/min. A 32 full-factorial design using Design Expert® software was employed for analytical method development in which mobile phase composition and flow rate were chosen as independent variables and the retention time (RT), tailing factor (TF) and theoretical plate count (TP) were selected as responses of the study. Statistically significant models were obtained for the development of the method (p-value <0.05). A UV spectroscopic method was also developed as a representative of the RP-UHPLC method that can offer comparable results while being more accessible and cost-effective. The developed methods were validated in accordance with ICH Q2(R1) guidelines, demonstrating excellent specificity, linearity (R² > 0.999), accuracy (recovery rates of 98–102%), precision (%RSD < 2%), robustness, ruggedness and system suitability. These results confirm the reliability and suitability of the methods for routine quantification of Tofacitinib Citrate (TFC) in both pharmaceutical and research settings. Overall, the development of the RP-UHPLC method and its corresponding UV spectroscopic method demonstrates a comprehensive approach to the analysis of Tofacitinib citrate.

The purpose of this study was to develop a new method for simultaneously determining the presence of Dapagliflozin propanediol monohydrate (DAPA) and Bisoprolol Fumarate (BISO) in a tablet formulation using reverse-phase high-performance liquid chromatography. The developed technique utilized an Inertsil ODS 3V (5 μm, 4.6*250mm) column with a 60:40 % v/v 0.2 % perchloric acid in water and acetonitrile, a flow rate of 1 ml/min, an injection volume of 10 µl and UV detection at 225 nm for both DAPA and BISO. The system suitability test, within acceptable limits, validates method reliability. Linearity calibration curves cover a concentration range for DAPA 20-150 µg/ml and BISO 10-75 µg/ml. Accuracy studies using the standard addition method produce recovery values between 99.49% and 99.52% for both drugs, demonstrating method accuracy. Precision studies (Repeatability and intermediate precision) reveals %RSD values constantly below 2 % highlighting method reproducibility. Robustness study promotes method reliability under small deliberate changes. The practicality of the method is demonstrated by its application to a pharmaceutical tablet formulation, which precisely quantifies DAPA (101.92%) and BISO (100.50%).

Cefoperazone (CPZ) is a third-generation cephalosporin used to treat bovine mastitis. The association with steroidal anti-inflammatory drugs, such as prednisolone (PRED), provides an improvement in the animal's clinical response, which justifies its use. An analytical method capable of simultaneously determining the association between CPZ and PRED by High Performance Liquid Chromatography coupled with a Diode Array Detector (HPLC-DAD) was developed. The method was applied in intramammary ointments, showing linearity, for CPZ, from 0.25 to 25 μg mL-1 (r=0.9999); and, for PRED, from 0.75 to 30 μg mL-1 (r=0.9997), with low limits of detection and quantification, precision with coefficients of variation less than 2%, in accuracy, presented recovery close to 100% for both drugs, in addition to demonstrating their robustness by the Youden test, which evaluated the effects and concluded that the altered parameters in the test were not sufficient to change the values obtained in the determinations. The test was also applied to the commercial sample for quality control purposes, with extraction efficiency being 69.66% for CPZ and 72.36% for PRED. Thus, the developed and validated method can be safely applied in the analysis of the studied drugs.

Clindamycin (CLIN) is an antibiotic derived from lincosamide, produced from Streptomyces lincolnensis. Studies in the literature demonstrate that the evaluation of this drug, although effective, predominantly uses analytical conditions with the use of toxic solvents, which are against the principles of Green Analytical Chemistry (GAC). In this context, the objective was to develop and validate an eco-friendly method by spectrophotometry in the ultraviolet (UV) region for the quantitative evaluation of CLIN in capsules. In addition, the proposed method was evaluated for greenness by the National Environmental Methods Index (NEMI), Ecological Scale Assessment (ESA) and Analytical GREEnness Metric (AGREE). Purified water and ethanol (50:50, v/v), quartz cuvette and wavelength of 318 nm and potassium permanganate as an oxidizing agent were used. The method was linear in the range of 0.5 to 5 µg mL-1 (0.9998), precise (RSD < 5 %); selective through spectral overlap and forced degradation; accurate (99.85%); robust to changes in wavelength and cuvette capacity; content analysis was of 102.55 % and NEMI presented all 4 green quadrants; ESA, score of 79, which characterizes an excellent green analysis; and AGREE score of 0.8, thus characterizing it as a green method through the 12 GAC principles. The method was developed and validated and can be used for quantitative evaluation of CLIN in capsules. Furthermore, the method was considered green through the greenness profiling tools NEMI, ESA and AGREE.