Optimized Box-Behnken experimental design based response surface methodology and Youden's robustness test to develop and validate methods to determine nateglinide using kinetic spectrophotometry

Application of validated UV spectrophotometric and colorimetric method to quantify minoxidil in the development of trilayer dissolving microneedle: Proof of concept in ex vivo and in vivo studies in rats

Alopecia areata (AA) is an autoimmune-induced hair loss condition, by utilizing MNX, a hair growth-promoting compound. However, minoxidil (MNX) administration's efficacy is hindered by low bioavailability and adverse effects. To enhance its delivery, Trilayer Dissolving Microneedles (TDMN) are introduced, enabling controlled drug release. The study's primary was to establish a validated UV-Vis Spectrophotometer method for Minoxidil analysis in rat skin affected by alopecia areata. This method adheres to International Conference Harmonization (ICH) and FDA guidelines, encompassing accuracy, precision, linearity, quantification limit (QL), and detection limit (DL). The validation method was conducted through two approaches, namely UV region validation using PBS and the colorimetric method in the visible region (Vis). The validated approach is then employed for assessing in vitro release, ex vivo permeation, and in vivo pharmacokinetics. Results indicate superior MNX extraction recovery using methanol compared to acetonitrile. Method C (5mL methanol) is optimal, offering high recovery with minimal solvent usage. Precision assessments demonstrate %RSD values within MNX guidelines (≤15%), affirming accuracy and reproducibility. UV-Vis spectroscopy quantifies MNX integration into TDMN, using PVA-PVP, with concentrations aligning with ICH standards (95% to 105%). In conclusion, TDMN holds promise for enhancing MNX delivery, mitigating bioavailability and side effect challenges. The validated UV-Vis Spectrophotometer method effectively analyzes MNX in skin tissues, providing insights into AA treatment and establishing a robust analytical foundation for future studies.

Response surface methodology combined Box-Behnken design optimized green kinetic spectrophotometric and HPLC methods to quantify angiotensin receptor blocker valsartan in pharmaceutical formulations

The high-performance liquid chromatographic (HPLC) and kinetic spectrophotometric methods were established to compute valsartan (VAL) in pharmaceutical formulations. The spectrophotometric procedures adopted initial rate, fixed time, and equilibrium strategies to assess VAL. The method was based on the carboxylic acid group of the oxidized VAL with a mixture of potassium iodate (KIO₃) and potassium iodide (KI) at room temperature, producing a stable, yellow-coloured absorb at 352 nm. The critical parameters were optimized using green process optimization methodology such as Box-Behnken design (BBD) which belongs to response surface methodology (RSM). After the screening, experiments identified them as significant, and then three crucial factors were optimised: KI volume, KIO₃ volume, and reaction time against response as absorbance. The HPLC procedure was also optimized based on the desirability function on RSM-BBD. The parameters such as pH, methanol (%), and flow rate (ml/min) were optimized with the best responses: peak area, symmetry, and theoretical plates. The linearity of spectrophotometric and HPLC methods was within the range of 2-24 and 0.25-11.25 µg/ml, respectively. The developed procedures produced excellent accuracy and precision. The design of the experiment (DoE) setting explained and discussed the individual steps and the importance of independent and dependent variables used to develop the model and optimization. The method was validated as per the International Conference on Harmonization (ICH) guidelines. Furthermore, Youden's robustness study was applied with factorial combinations of the preferred analytical parameters and explored their influence with alternative conditions. The analytical Eco-Scale score was calculated and was found a better option as green methods to quantify VAL. The results were reproducible with the analysis completed with biological fluid and wastewater samples.

Optimized Box-Behnken Design Combined Response Surface Methodology to Determine Calcium and Iron Contents Using Visible, Atomic Emission and Atomic Absorption Spectrophotometry in Vegetables and Wastewater Samples

BACKGROUND

Calcium and iron are crucial essential minerals. Iron is mainly responsible for transporting oxygen in the body and the immune system. In comparison, calcium's primary function is in human bones and teeth. Due to that, it is vital to quantify the amount in vegetables.

OBJECTIVE

Optimization and validation of three analytical procedures, visible, atomic emission spectrophotometry (AES), and atomic absorption spectrophotometry (AAS), were developed to determine calcium and iron in vegetables and wastewater samples using response surface methodology (RSM) via Box-Behnken design (BBD). The design helps to reduce experiment trials with selected variables to find a correlation between them and their respective dependent variables.

METHODS

Method I was developed to quantify calcium in vegetables mixed with concentrated 3M HNO3 and heated to reflux as per the BBD. Then it was cooled, filtered, and completed with 3M HNO3 to be carried out utilizing AES and AAS. For method II, vegetables were mixed with nitric acid and sulfuric acid solution with an optimized 5M KSCN solution, which was computed using the AAS and visible spectrophotometry.

RESULTS

First, percentage of water content was calculated for all vegetables, higher in malabar spinach and lower in peas. The calcium and iron contents were present within 0.59-2.68 mg and 35.8-211.5 mg, respectively, in 100 g of vegetables. The results showed a higher amount of iron was available in spinach and a lower amount in okra. In contrast, the highest calcium amount was present in broccoli and the lowest amount was in peas. The calcium and iron content were between 0.015-137.25 and 0.01-147.85 µg/mL in the wastewater samples.

CONCLUSIONS

These methods can help to determine the amount of calcium and iron for the quality control samples in research and development, food, and the environmental industry.

HIGHLIGHTS

Three validated analytical techniques quantify calcium and iron in vegetables and wastewater samples. The RSM-BBD optimized the method and determined its crucial factors.

Box–Behnken Design Used to Optimize the Simultaneous Quantification of Amitriptyline and Propranolol in Tablet Dosages by RP-HPLC-DAD Method and Their Stability Tests

This study’s goal is to use a Box–Behnken design [BBD] methodology to create a new reverse-phase high-performance liquid chromatography diode-array detection [RP-HPLC-DAD] method for the simultaneous quantification of Amitriptyline and Propranolol in tablet dosages. The amitriptyline and propranolol standard drug peaks were obtained using a C-18 column with a dimension of 4.6 × 100 mm and a particle size packing of 2.5 µm at the retention time of 5.328 and 7.48 min, respectively. The mobile phase composition was a 75:25 mixture of methanol and 0.1 percent orthophosphoric acid, flowing at 1.0 mL/min at 26 °C. The peaks were identified at 257 nm after injecting 20 µL of the sample. An assay of the marketed tablets was performed, and the result was 101.33 and 99.4% for amitriptyline and propranolol, respectively, when compared to the standard calibration curve. Forced degradation investigations, such as acid, base, H2O2, and neutral condition, were performed. The results for both medications in term of % degradation were as follows: amitriptyline (16.07, 91.92, 26.98, and 0.64) and propranolol (15.84, 11.52, 9.09, and 3.62). According to the ICH criteria, the findings of the validation parameters were within an acceptable range. The new RP-HPLC-DAD method with BBD application is easy, accurate, and time-saving.

Simultaneous Estimation of Escitalopram and Clonazepam in Tablet Dosage Forms Using HPLC-DAD Method and Optimization of Chromatographic Conditions by Box-Behnken Design

The study aimed to develop a new reverse-phase high-performance liquid chromatography (RP-HPLC) method with diode array detection (DAD) detection for simultaneous estimation of escitalopram (EST) and clonazepam (CZP) in tablet dosage forms with a quality by design (QbD) approach. The chromatographic conditions were optimized by Box-Behnken design (BBD) and developed method was validated for the linearity, system suitability, accuracy, precision, robustness, sensitivity, and solution stability according to International Council for Harmonization (ICH) guidelines. EST and CZP standard drugs peaks were separated at retention times of 2.668 and 5.046 min by C-18 column with dimension of 4.6 × 100 mm length and particle size packing 2.5 µm. The mobile phase was methanol: 0.1% orthophosphoric acid (OPA) (25:75, v/v), with a flow rate of 0.7 mL/min at temperature of 26 °C. The sample volume injected was 20 µL and peaks were detected at 239 nm. Using the standard calibration curve, the % assay of marketed tablet was founded 98.89 and 98.76 for EST and CZP, respectively. The proposed RP-HPLC method was able to detect EST and CZP in the presence of their degradation products, indicating the stability-indicating property of the developed RP-HPLC method. The validation parameter’s results in terms of linearity, system suitability, accuracy, precision, robustness, sensitivity, and solution stability were in an acceptable range as per the ICH guidelines. The newly developed RP-HPLC method with QbD application is simple, accurate, time-saving, and economic.