A Novel RP-HPLC-DAD Method Development for Anti-Malarial and COVID-19 Hydroxy Chloroquine Sulfate Tablets and Profiling of In-Vitro Dissolution in Multimedia

Development, evaluation of critical method variables and stability assessment using a Box-Behnken design for the determination of organic impurities in a pharmaceutical dosage form of a centrally acting muscle relaxant drug chlorzoxazone

This study validates a stability-indicating LC method for detecting organic impurities in the chlorzoxazone dosage form. Using a Waters X-Select R HSS T3 analytical column, mobile phase of it was made by mixing of water, methanol, and glacial acetic acid in the ratio of 700:300:10 (v/v/v). The drug product and drug substance were subjected to the stress conditions such as acid, base, oxidation, heat, and photolysis as per the recommendations of the International Conference on Harmonization (Q2) methodology. The study revealed the susceptibility of 4-chloro-2-aminophenol to alkaline environments, emphasizing peak homogeneity and stability. The method verification, per ICH guidelines and USP<1225>, established precision, specificity, linearity, accuracy, and robustness for quality control. The mean impurity recovery ranged from 95.5% to 105.2%, the correlation coefficient (r) was greater than 1.000, and the RSD values (n = 6) ranged from 0.6% to 5.1% across the LOQ-150% ranges. Full-factorial design tested final method conditions, evaluating multiple parameters concurrently. Graphical optimization within the design space defined strong method requirements, ensuring consistent and reliable outcomes. The study develops and validates chlorzoxazone stability-indicating methods, employing advanced statistical approaches like design of experiments and factorial design, with resilient conditions established through graphical optimization of the design space.

Development and validation of apalutamide-related substances method in solid dosage forms using HPLC

A related-substances method was developed for the anticancer drug formulation apalutamide 60 mg tablets and validated using a liquid chromatography gradient elution method. All of the impurities and degradants were separated using the Luna Omega 5 μm Polar C₁₈ , (250 × 4.6) mm HPLC column with a 1.0 ml min^-1 flow rate. The detection was done at 225 nm by injecting the 10 μl of injection volume, controlling the sample temperature at 10°C and maintaining the column compartment temperature at 30°C. The total run time was 85 min. A 0.01 m disodium phosphate dihydrate pH 4.20 ± 0.05 buffer mixed with acetonitrile in the ratio of 73:27 (v/v) was used as mobile phase A. Mobile phase B consisted of water and acetonitrile in the ratio 30:70 (v/v). The proposed method was validated as per the current regulatory guidelines. The method precisions (RSD) at 100% specification level were 1.41, 1.74, 1.84, and 1.66% for the four impurities. The accuracy results were obtained between 96.0 and 106.3% for the limit of quantitation to the 150% level. The standard and sample solutions stability were established for 44 h at 10°C. The correlation coefficient (r) value was >0.999 for all four impurities, indicating good linearity between the concentration and peak response: 0.9999, 0.9999, 0.9999 and 1.0000. These results show the method's linearity. The three filter compatibility was proved and it was concluded that 0.45 μm Nylon, PTFE and PVDF filters are suitable. The robustness of the method was established by varying the conditions. The method specificity was proved and the forced degradation data reveal the method's stability-indicating nature.

Regulatory Perspective Development and Validation of Novel RP-HPLC Method of Midostaurin Drug Substance using Analytical Quality by Design approach; Identified Major Degradation Compounds Mass by Using LC-MS technique

Midostaurin (MTN) was designated as an orphan medicinal product, and it is an emerging drug for treating acute myeloid leukemia and advanced systematic mastocytosis, respectively. The proposed method was developed and validated to evaluate related impurities of MTN. Those impurities were separated by using YMC Trait C18 ExRS, (150 mm × 4.6 mm), 3 μm column. The mobile phase A consists of a 10 mM concentration of phosphate buffer adjusted to pH 3.0 with diluted orthophosphoric acid and mobile phase B contains 90 % acetonitrile with 10 % water. The optimized chromatographic conditions such as flow rate 0.5 mL min^-1 , injection volume 10 μL, UV detection at 290 nm, and a linear gradient program set upto 65 minutes. It was developed through an analytical QbD approach. A systematic flow chart explained the evaluation, control, and life cycle management method. As part of the method evaluation, a risk assessment was conducted. It has been validated as per current ICH guidelines. The recovery study and linearity ranges were established from LOQ to 150 % optimal concentrations. The validation results were found between 95.5 to 102.5 % for recovery and r² 0.9998 to 0.9999 for linearity of all identified impurities. The method precision results were achieved below 10% of RSD. Performed forced degradation studies in chemical and physical stress conditions. The compound was sensitive to chemical stress conditions. During the study, the analyte was degraded, converted into identified degradation impurities, and found its molecular mass by the LC-MS technique.

Unraveling the origin of interactions of hydroxychloroquine with the receptor-binding domain of SARS-CoV-2 in aqueous medium

Interactions of hydroxychloroquin (HCQ) with the receptor binding domain (RBD) of SARS-CoV-2 were studied from atomistic simulation and ONIOM techniques. The key-residues of RBD responsible for the human transmission are recognized to be blocked in a heterogeneous manner with the favorable formation of key-residue:HCQ (1:1) complex. Such heterogeneity in binding was identified to be governed by the differential life-time of the hydrogen bonded water network anchoring HCQ and the key-residues. The intermolecular proton transfer facilitates the most favorable Lys417:HCQ complexation. The study demonstrates that off-target bindings of HCQ need to be minimized to efficiently prevent the transmission of SARS-CoV-2.

In vitro Dissolution Profile at Different Biological pH Conditions of Hydroxychloroquine Sulfate Tablets Is Available for the Treatment of COVID-19

Hydroxychloroquine sulfate is one of an extensive series of 4-aminoquinolines with antimalarial activity. Moreover, it is used for the treatment of rheumatoid arthritis. Sometimes, hydroxychloroquine sulfate is beneficial for the treatment of autoimmune diseases. Based on recent clinical experiments, it is exploited for the treatment of COVID-19, coronavirus across the globe. The chromatogram separation was achieved by using Agilent, Zorbax C8, 250 mm × 4.6 mm i.d., column. The buffer consists of 0.01 M of 1-pentane sulfonic acid and 0.02% of orthophosphoric acid in purified water. Mixed buffer, acetonitrile, and methanol (800:100:100 v/v). The flow rate was 1.0 ml min-1, and injection volume was 10 μl. Detection was made at 254 nm by using a dual absorbance detector (DAD). The reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed and validated as per the current International Conference on Harmonization (ICH) guidelines to estimate hydroxychloroquine sulfate tablets. As part of method validation, specificity, linearity, precision, and recovery parameters were verified. The concentration and area relationships were linear (R 2 > 0.999) over the concentration range of 25-300 μg ml-1 for hydroxychloroquine (HCQ). The relative standard deviations for precision and intermediate precision were <1.5%. The proposed RP-HPLC generic method was applied successfully to evaluate the in vitro dissolution profile with different pH conditions such as 0.1 N HCl, pH 4.5 acetate buffer, and pH 6.8 phosphate buffers as US-marketed reference products.