Regulatory Perspective Reverse Engineering Analysis of the Mast Cell Stabilizer and the Histamine Receptor Antagonist (Olopatadine HCl): Instrumental and Classical Methods for Multiple Formulations.

This study evaluates the unknown qualitative (Q1) and quantitative (Q2) formulas for nasal spray and ophthalmic solution formulations of olopatadine HCl by classical and instrumental techniques to match the generic formula with reference-listed drugs to avoid clinical study. Reverse engineering of olopatadine HCl nasal spray 0.6% and ophthalmic solution 0.1, 0.2% formulations was accurately quantified using a simple and sensitive reversed-phase high-performance liquid chromatography (HPLC) method. Both formulations possess similar components, namely ethylenediaminetetraacetic acid (EDTA), benzalkonium chloride (BKC), sodium chloride (NaCl), and dibasic sodium phosphate (DSP). These components were qualitatively and quantitatively determined using the HPLC, osmometry, and titration techniques. With derivatization techniques, EDTA, BKC, and DSP were determined by ion-interaction chromatography. NaCl in the formulation was quantified by measuring the osmolality and using the subtraction method. A titration method was also used. All the employed methods were linear, accurate, precise, and specific. The correlation coefficient was >0.999 for all components in all the methods. The recovery results ranged from 99.1 to 99.7% for EDTA, 99.1-99.4% for BKC, 99.8-100.8% for DSP, and 99.7-100.1% for NaCl. The obtained % relative standard deviation for precision was 0.9% for EDTA, 0.6% for BKC, 0.9% for DSP, and 1.34% for NaCl. The specificity of the methods in the presence of other components, diluent, and the mobile phase was confirmed, and the analytes were specific.

QbD-based stability-indicating liquid chromatography (RP-HPLC) method for the determination of flurbiprofen in cataplasm.

A nonsteroidal drug called flurbiprofen (FBN) has analgesic, anti-inflammatory and antipyretic activity. Currently the determination of FBN in cataplasm does not have any pharmacopeial method. However, the drug substance, tablet and ophthalmic solution formulations do have pharmacopeial methods. The development and validation of an accurate, precise and stability-indicating analytical method for the determination of FBN in cataplasm formulations is reported. The gradient method was employed for the quantification of FBN in the presence of internal standards such as biphenyl. A nonpolar separation phase (C18 , 250 × 4.6 mm, 5 µm Inertsil column; GL Sciences) was used. The optimal flow rate, column oven temperature, injection volume and detector wavelengths were 1.0 ml/min, 40°C, 20 µl and 245 nm, respectively. Mobile phase A was a mixture of water and glacial acetic acid (30:1 v/v) pH adjusted to 2.20 with glacial acetic acid or 1 m NaOH; mobile phase B was methanol (100%). The gradient elution program was [time (min)/% B]: 5/60, 20/70, 25/70, 30/60 and 40/60. The obtained RSDs for the precision and intermediate precision were 0.7 and 0.5%. The percentage recovery ranged from 99.2 to 100.4%. The linear regression coefficient >0.9996 indicates that all peak responses were linear with the concentration. The sample and standard solutions were stable for up to 24 h on the benchtop and in the refrigerator. The critical peaks were well separated from the generated peaks owing to forced degradation, including diluent and placebo peaks. The method validation data and quality by design-based robustness study results indicate that the developed method is robust and fit for routine use in the quality control laboratory. The proposed method is specific, accurate and precise, and the quality by design utilized the first method for the determination of FBN in cataplasm formulations. Transdermal patches and gels have low extraction capacity and this method is applicable for quantification.

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.

Development and validation of novel RP-HPLC method for midostaurin determination using analytical quality by design approach from regulatory perspective and determination of major degradation compounds of midostaurin using LC-MS.

Midostaurin (MTN), designated as an orphan medicinal product, is emerging as an important drug for treating acute myeloid leukemia and advanced systematic mastocytosis. The proposed method was developed and validated to evaluate the related impurities of MTN. The impurities were separated using a YMC Trait C18 ExRS column (150 × 4.6 mm, 3 µm). Mobile phase A consisted of a 10-mM concentration of phosphate buffer adjusted to pH 3.0 with diluted orthophosphoric acid, and mobile phase B consisted of 90% acetonitrile and 10% water. The optimized chromatographic conditions were as follows: flow rate, 0.5 mL min-1 ; injection volume, 10 µL; UV detection, 290 nm; and linear gradient program, up to 65 min. The method was developed using an analytical quality by design approach. A systematic flow chart shows the evaluation, control, and life cycle management method. As part of method evaluation, risk assessment was conducted. The method has been validated per current guidelines of the International Conference on Harmonization. The recovery study and linearity ranges were established from the limit of quantification to 150% optimal concentrations. The recovery was found to be between 95.5 and 102.5%, and linearity (r2 ) was 0.9998-0.9999 for all the identified impurities. The method precision results were achieved below 10% of relative standard deviation. Forced degradation studies were performed under chemical and physical stress conditions. The compound was sensitive to chemical stress conditions. During the study, the analyte degraded and was converted into the identified degradation impurities, and its molecular mass was found using the LC-MS technique.

Unique liquid chromatography technique for the determination of mirabegron in the presence of polymers; robustness by Design Expert in the light of Quality by Design.

The current study is designed to estimate mirabegron in the presence of high molecular weight polymers using a unique liquid chromatography method and sample preparation technique. The proposed method is significant because of the many analytical issues faced during the development studies. Based on the experimental results, we finally achieved the stability-indicating power of the method. The adequately prepared mobile phase was in the ratio of pH 2.0 buffer and acetonitrile (80:20) v/v, and the buffer pH 2.0 was prepared as follows: 8.7 ml of perchloric acid, 2 ml of triethylamine and 3.0 g sodium hydroxide into 1 L of water mixed well. The system suitability parameters were achieved using a Waters X-Bridge C18 (4.6 × 150 mm, 3.5 µm) column and mobile phase. The optimized chromatographic conditions included a column temperature of 45°C, a flow rate of 1.0 ml min-1 ; an injection volume of 5 µl, UV 247 nm, and 15 min runtime. The method was validated and transferred to quality control as per International Conference on Harmonization Q2(R1) and the Chinese Pharmacopoeia 2020 edition <9101> and <9100>. The recovery and linearity results were obtained between 99.0 and 101.0%; the value of r2 was 0.9998. The method robustness study was established by utilizing the Design of Experiments part of the Quality by Design concept. The method's stability-indicating nature was proved by a forced degradation study; all of the conditions for analyte peak purity were passed, and mass balance was achieved. The method was used to determine mirabegron assay, as well as content uniformity, blend uniformity and cleaning samples. It is a user-friendly and cost-effective method.

Favipiravir (SARS-CoV-2) degradation impurities: Identification and route of degradation mechanism in the finished solid dosage form using LC/LC-MS method.

Favipiravir finished dosage was approved for emergency use in many countries to treat SARS-CoV-2 patients. A specific, accurate, linear, robust, simple, and stability-indicating HPLC method was developed and validated for the determination of degradation impurities present in favipiravir film-coated tablets. The separation of all impurities was achieved from the stationary phase (Inert sustain AQ-C18, 250 × 4.6 mm, 5-µm particle) and mobile phase. Mobile phase A contained KH2 PO4 buffer (pH 2.5 ± 0.05) and acetonitrile in the ratio of 98:2 (v/v), and mobile phase B contained water and acetonitrile in the ratio of 50:50 (v/v). The chromatographic conditions were optimized as follows: flow rate, 0.7 mL/min; UV detection, 210 nm; injection volume, 20 µL; and column temperature, 33°C. The proposed method was validated per the current International Conference on Harmonization Q2 (R1) guidelines. The recovery study and linearity ranges were established from the limit of quantification to 150% optimal concentrations. The method validation results were found to be between 98.6 and 106.2% for recovery and r2  = 0.9995-0.9999 for linearity of all identified impurities. The method precision results were achieved below 5% of relative standard deviation. Forced degradation studies were performed in chemical and physical stress conditions. The compound was sensitive to chemical stress conditions. During the study, the analyte degraded and converted to unknown degradation impurities, and its molecular mass was found using the LC-MS technique and established degradation pathways supported by reaction of mechanism. The developed method was found to be suitable for routine analysis of research and development and quality control.

A Quality by Design and green LC technique for the determination of mast cell stabilizer and histamine receptor antagonist (Olopatadine HCl) in multiple formulations.

Mast cell stabilizer and histamine receptor antagonist olopatadine hydrochloride (OPT) assay method predicated on LC have been established for the analysis in multiple formulations. The current method dealt with ophthalmic solution, nasal spray, and tablet formulation products. The isocratic chromatography method was optimized and validated with a Boston green C8 column (150 × 4.6 mm, 5 µm i.d.). Sodium dihydrogen phosphate buffer (pH 3.5) with acetonitrile in the ratio of 75:25 (v/v) was used as a mobile phase at a flow rate of 1.0 mL min-1 and at the column temperature of 30°C, and the detection was done at 299 nm. The method was validated as per International Council for Harmonisation (ICH) guidelines and United States Pharmacopoeia (USP). The accuracy results ranged from 99.9 to 100.7%, % relative standard deviation (RSD) from the precision was 0.5, and correlation coefficient from the linearity experiment was > 0.999. Solution stability was established for 24 h at room temperature and refrigerator conditions, and it was found that the solutions were stable. Using quality by design-based experiment designs, critical quality attributes were studied and it was found that the method was robust. In all the forced degradation studies peak purity was passed, and no interference was found at the retention time of the active component. The method validation data demonstrated that the developed method is linear, precise, accurate, specific, robust, and stable for the determination of OPT from multiple formulations. Analytical eco-scale tool, Green Analytical Procedure Index (GAPI) tool, and the National Environmental Method Index (NEMI) were used to evaluate the greenness of the method, and the analytical eco-score of 77 for the presented method was found to be excellent.

Stability-indicating reversed-phase-HPLC method development and validation for sacubitril/valsartan complex in the presence of impurities and degradation products: Robustness by quality-by-design approach.

According to current regulatory guidelines, a stability-indicating method has been developed to determine the impurities in sacubitril (SCB) and valsartan (VLS) tablet dosage forms and perform robustness studies using the design of experiments approach. The present study was initiated to understand quality target product profile, analytical target profile, and risk assessment for method variables that affect the method response. A reversed-phase-HPLC system was equipped with a Phenomenex Gemini-NX C18 column (150 × 4.6 mm, 3 µm) and a photo diode array detector. A gradient mobile phase was used in this research work. The detection was performed at 254 nm; the flow rate was 1.5 mL/min, and the column temperature was maintained at 30°C. The proposed method was validated per the International Council for Harmonisation Q2 (R1) guidelines. The coefficient of correlation was >0.999 for all impurities. The limits of detection and quantification were evaluated for SCB, VLS, and all impurities. The precision and accuracy were obtained for SCB, VLS, and their related impurities. Intra- and inter-day relative standard deviation values were less than 10.0%, and the recoveries of impurities varied between 90.0 and 115.0%. Based on the validation results, the proposed DoE method can estimate SCB and VLS impurities in the finished dosage form.

Determination of progesterone (steroid drug) in the semi-solid dosage form (vaginal gel) using a stability-indicating method by RP-HPLC/PDA detector.

A simple stability-indicating method was developed and validated for the determination of progesterone (a steroid drug) in the semi-solid dosage form. All the impurities were separated from the main compound with a simple stationary phase (Eclipse XDB, C8, 150 × 4.6 mm, 5 µm). The mobile phase A contained phosphate buffer and acetonitrile in the ratio of 90:10, v/v, and mobile phase B contained purified water and acetonitrile in the ratio of 10:90, v/v. The optimized chromatographic conditions were as follows: flow rate, 1.0 mL min-1 ; UV detection, 241 nm; injection volume, 10 µL; and the column temperature, 30°C. The method was validated as per the current ICH Q2 guidelines. The recovery study and linearity ranges were established from 50 to 300% optimal concentrations. The method validation results were found between 98 and 102% for accuracy and r2  = 0.999 for linearity. Forced degradation in hydrolytic, oxidative, thermolytic, and photostability conditions was performed, and the stability indicating nature of the method was proved. Based on the validation and forced degradation results, the current method was found to be specific, precise, accurate, linear, robust, and stability-indicating method. The developed method was cost effective and easy to handle for quality control analysis.

Unique Quality by Design Approach for Developing HPLC and LC-MS Method for Estimation of Process and Degradation Impurities in Pibrentasvir, Antiviral Agent for Hepatitis C.

Pibrentasvir (PIB) was approved for treating hepatitis C patients. A specific, accurate, linear, robust, and stability-indicating method was developed and validated for determining degradation impurities present in the PIB drug substance by studying the quality by design (QbD) principles. All identified degradation impurities were separated with the stationary phase HALO C18, 150 mm × 4.6 mm, 2.7 µm. Mobile phase A contains pH 2.5 phosphate buffer and acetonitrile in the ratio of (70:30, v/v), and mobile phase B contains water and acetonitrile in the ratio of (30:70, v/v), respectively. The chromatographic conditions were optimized, such as flow rate of 0.8 mL/min, UV detection at 252 nm, injection volume of 20 µL, and column temperature of 40 °C. The proposed method was validated per the current ICH Q2 (R1) guidelines. The recovery study and linearity ranges were established from limit of quantification (LOQ) to 300% optimal concentrations. The method validation results were between 98.6% and 106.2% for recovery, and linearity r 2 was more than 0.999 for all identified impurities. The method precision results achieved below 5% relative standard deviation (RSD). The forced degradation results demonstrated that the drug was sensitive to chemical stress conditions. During the stress study, degrading impurities were identified by the LC-MS technique and the mechanism pathway. A QbD-based experimental design (DoE) approach was used to establish the robustness of the method.