Quality Control Of Formulations Research Articles

Development and Validation of UV Spectrophotometric Method for Simultaneous Estimation of some SGLT-2 and DPP-4 inhibitor in Bulk and Pharmaceutical Dosage Form

The result of pharmaceutical industry research for the new class and the new combination of drugs for the treatments of diabetes is the newly approved combination of Remogliflozin etabonate (RGE) and Teneligliptin Hydrobromide hydrate (TG). For the quality control of this formulation, the smart, reproducible and non-sophisticated spectroscopic techniques were developed by modification of UV spectra. The proposed methods exhibited Beer’s law in the range of 10 to 60µg/ml and 5 to 30µg/ml for RGE and TG correspondingly. The mean percentage recovery was found to be in the range of 98.60 to 101.55 for RGE and 99.87 to 100.21 for TG. Further, both analytes were quantified from the formulation using proposed spectroscopic methods with high accuracy. The suggested technique is simple, accurate and reproducible, hence could be used for regular quality control of formulation consisting of RGE and TG. The developed method can be used for analysis of stability samples and routing quality control evaluation in tablet formulation.

Review on method development and validation for different pharmaceutical dosage form

Pharmaceutical analysis is crucial for bulk and formulation quality control. Due to global medication manufacturing and pharmaceutical sector expansion, innovative analytical methods are in demand. Developing analytical procedures is now the most significant part of analysis. Improvements in analytical instruments have led to new analytical methods. The improvement of analytical methodologies and technologies has reduced analysis time, increased precision and accuracy, and decreased analysis costs. As a consequence, the majority of pharmaceutical businesses are investing heavily in specialist analysis labs. Analytical techniques for active pharmaceutical ingredients (API), excipients, drug products, degradation products and related substances, residual solvents, and other chemicals are created and verified. As a consequence, it has become an essential component of the regulating organization's standards. Development of analytical methodologies leads to official test methods. Quality control labs utilize these methods to verify drug identity, purity, safety, effectiveness, and performance. Production analytical methods are becoming relevant to regulators. Regulatory agencies expect applicants to demonstrate control of the drug development process using established analytical methodologies.

Simultaneous Spectrophotometric Determination of Piroxicam, Naproxen, Diclofenac Sodium and Mefenamic Acid in Pharmaceutical Formulations by Partial Least Squares Method

A chemometric method, partial least squares regression (PLS) was applied for the simultaneous determination of piroxicam (PIR), naproxen (NAP), diclofenac sodium (DIC), and mefenamic acid (MEF) in synthetic mixtures and commercial formulations. The proposed method is based on the use of spectrophotometric data coupled with PLS multivariate calibration. The Spectra of drugs were recorded at concentrations in the linear range of 1.0 - 10 μg mL-1 for NAP and from 1.0 - 20 μg mL-1 for PIR, DIC, and MEF. 34 sets of mixtures were used for calibration and 10 sets of mixtures were used for validation in the wavelength range of 200 to 400 nm with the wavelength interval λ = 1 nm in methanol. This method has been used successfully to quantify drugs in pharmaceutical formulations with no interference from excipients. The proposed method is simple, quick, and can be used as an alternative analysis tool in drug and formulation quality control as well as process control.

Method development and validation of nifedipine and lignocaine by RP-HPLC

For the validation of the nifedipine and lignocaine assay by reverse phase high performance liquid chromatography, in both pure form and tablet dosage form, a straightforward, quick, and exact approach has been established. ACN, Methanol, and perchloric acid were used as the mobile phase in chromatography on a Kromasil 100-5-C18 (4.6 x 150 mm, 5 m) column at a flow rate of 1.0 ml/min. 210 nm was used for detection. Nifedipine and lignocaine had retention times of 3.30 and 5.820.02 min, respectively. In the concentration range of 10–50 mg/ml of nifedipine and 20–100 mg/ml of lignocaine, the approach yields linear responses. The method precision for the assay result was less than 2.0%RSD, and the Nifedipine and lignocaine individual assays should be between 98% and 102.0%, respectively. The technique is helpful for pharmaceutical and bulk formulation quality control.

Smart UV Derivative Spectrophotometric Methods for Simultaneous Determination of Metformin and Remogliflozin: Development, Validation and Application to the Formulation

Abstract: Background: The result of pharmaceutical industry research for the new class and the new combination of drugs for the treatments of diabetes is the newly approved combination of metformin (MET) and remogliflozin (REM). For the quality control of this formulation, three smart, reproducible and non-sophisticated spectroscopic techniques were developed by modification of UV spectra. Materials and Methods: The first two methods were based on the measurements of the peak height of the third derivative and second derivative ratio spectra of MET and REM and the third method was the constant center spectrum subtraction method. Results: The proposed methods exhibited Beer’s law in the range of 2.5 to 30 μg/ml and 1 to 24 μg/ml for MET and REM correspondingly by all three methods. The mean percentage recovery was found to be in the range of 99.08% to 100.15% for MET and 98.73% to 100.27% for REM. Further, both analytes were quantified from the formulation using proposed spectroscopic methods with high accuracy. Comparison of all three methods with the reported HPLC method showed no variation in the assay outcomes in relation to accuracy and precision. Conclusion: The suggested techniques are simple, accurate and reproducible, hence could be used for regular quality control of formulation consisting of MET and REM. Key words: Metformin, Remogliflozin, UV, Derivative spectroscopy, Validation, Formulation.

Quality of African moringa ( Moringa stenopetala ) leaf samples by liquid chromatography of phenolics, loss on drying and ash content

The aim of this study was to evaluate the quality of African moringa (Moringa stenopetala) leaf preparations using easily applicable analytical methods. For this purpose, a novel simple and fast LC-UV method was developed and validated to determine the most common phenolic compounds. The method showed good linearity with determination coefficients (r2) ≥ 0.999. Detection limits were below 0.4 μg/ml and quantification limits below 1.2 μg/ml. Relative standard deviation (RSD) values for intra- and inter-day precision were less than 2% and recoveries were close to 100%. Robustness of the method was evaluated using an experimental design. The developed method was applied to analyze some commercial moringa leaf samples obtained from Ethiopia. Unknown compounds were tentatively identified as neochlorogenic acid and kaempferol 3-O-rhamnosylglucoside (KRG) by means of mass spectrometry (MS). Rutin was found to be the most common compound. Its content in samples varied from 2 to 18 mg/g. The amounts of (neo)chlorogenic acid and KRG were less than 2 mg/g, while quercetin and caffeic acid were not detected. The method allowed to observe differences in phenolic composition between regions. Results for loss on drying and ash content revealed that 40% and 50%, respectively, of the samples were not compliant. Novelty Impact Statement Quality control of formulations of Moringa stenopetala leaves is as good as non-existent due to lack of suitable test procedures. The analytical methods proposed here are easily applicable in low-income countries and include a novel LC-UV method for the phenolic compounds, loss on drying, and ash contents. The combined tests were found to be successful in differentiating the quality of different commercial samples.

Environmental sustainable mathematically processed UV spectroscopic methods for quality control analysis of remogliflozin and teneligliptin: Evaluation of greenness and whiteness

Environmental sustainable analytical methods were developed by mathematical modification of UV absorption spectra for quality control study of multicomponent formulations consisting of remogliflozin (REM) and teneligliptin (TEN), with good sensitivity and selectivity. Then analytes were quantified by measuring the peak amplitude of the first derivative spectra at zero crossing points at 230.2 nm and 213.8 nm for REG and TEN in the first derivative method. The second method involves the formation of ratio spectra and taking the absorption difference at two selected wavelengths of peak and trough of a spectrum. In the ratio first derivative method peak amplitudes were measured at 235.2 nm and 259.1 nm for simultaneous quantification of REM and TEN respectively. The fourth method was based on the measurement of the peak amplitude of zero-order spectra of analytes generated from the mixture spectrum by subtraction of a constant from the ratio spectrum followed by multiplication with divisor spectrum, Further, the proposed methods were validated systematically to confirm the linearity, precession, accuracy, sensitivity, and selectivity. Finally, validated UV spectroscopic methods were applied for simultaneous quantification of REM and TEN from formulation, and laboratory mixed solutions and statistically compared with the reported HPLC method. Further, recently developed AGREE, Hexagonal greenness and white analytical chemistry, a whiteness evaluation tools were applied to the proposed UV spectroscopic methods and found to be safer analytical methods, compared to the reported expensive, time-consuming and toxic HPLC method. Hence, proposed UV spectroscopic methods could be used for routine quality control of formulations containing REM and TEN.

DEVELOPMENT OF METHOD AND VALIDATION FOR ASSAY IN IRINOTECAN HYDROCHLORIDE INJECTION BY APPLYING STABILITY INDICATING HPLC METHODOLOGY BY HPLC

A validated HPLC technique for determining Irinotecan Hydrochloride (IRN) in pharmaceutical formulations was developed. For this chromatographic investigation, isocratic elution at a flow rate of 1.0 ml/min was utilized on Zorbax C18 150mm 4.6 mm, 5μ, or similar. The mobile phase is made up of 45 volumes of methanol and 55 volumes of buffer solution. The UV detection wavelength was 220 nm, and a sample of 10.0 μl was injected. The run time for Sample, Unmarked, Placebo, System Suitability and Sensitivity solutions is approximately 12 minutes, and 60 minutes for diluted Regular. The approximate retention time for IRN was determined to be 3.8 minutes. The percentage R.S.D. IRN was determined. Irinotecan's mean percentage recovery is found to be within the specified limit. The approach was validated in accordance with ICH recommendations. As a result, the suggested HPLC approach may be successfully used for routine formulation quality control examination. The devised approach is simple and superior to the methods published in the literature.

Effect of process variables on imiquimod micronization using a supercritical antisolvent (SAS) precipitation technique

This study aimed to promote the micronization of imiquimod, a poorly water-soluble immunostimulant drug, using the supercritical antisolvent (SAS) process. The effect of temperature, pressure and drug concentration on drug particle formation, size and yield was evaluated. Increasing pressure tends to increase size and decrease yield. Increasing concentration results in raises in size and yield. Increasing temperature leads to size reduction and increase in yield. The combination of process variables shows that increase in pressure and concentration leads to an increase in size and a reduction in yield, and that pressure and temperature combined, as well as the combination of temperature and concentration, leads to reduction in size and yield. The micronization process was not capable of promoting improvement in drug dissolution rate or limit. However, a significant gain was observed in data reproducibility, which can contribute considerably to the quality control of formulations containing imiquimod.

ANALYTICAL METHOD DEVELOPMENT AND VALIDATION FOR THE ESTIMATION OF TRAMADOL IN BULK AND ITS FORMULATIONS BY UV-SPECTROSCOPY

The present study describes a simple, accurate, precise and cost-effective UV-Spectrophotometric method for the estimation of Tramadol Hydrochloride, an analgesic, in bulk and pharmaceutical dosage form. The drug was dissolved in double distilled water (used as solvent). Because of cost-effective and minimal maintenance, UV-spectrophotometry is always preferred at small scale industries. The λmax or the absorption maxima of the pure drug was found to be 271nm. A linear response was observed in the range of 30 to 150μg/ml with the regression co-efficient of 0.999. The method was validated for different parameters as per the ICH (International Conference for Harmonization) guidelines. This method can be used for the determination of Tramadol Hydrochloride in quality control of formulation without interference of the excipients. The developed method is simple, precise, rugged, robust, and economical. The method can be used for routine analysis of tramadol from its tablet formulation. The described methods can be readily utilized for analysis of pharmaceutical formulation.

Method development and validation for simultaneous estimation of brinzolamide and brimonidine in pharmaceutical dosage form by using RP-HPLC

A high performance liquid chromatographic method was developed and validated for the simultaneous determination of brinzolamide and brimonidine by employing an isocratic RP-HPLC Kromasil C18 (4.6 x 250mm, 5µm) column resulted in an adequate separation for brinzolamide and brimonidine with retention time of 2.121 min and 2.801min respectively. Best resolution was achieved with the Perchloric acid (0.1%) and acetonitrile with ratio of (58:42) as mobile phase pumped at the flow rate of 1.0 ml/min with the detection wavelength of 251 nm. Regression coefficient for both brinzolamide and brimonidine was found to be 0.998 and 0.998 respectively indicating linearity within the concentration range. The validation parameters like linearity, precision, accuracy, limit of detection and limit of quantitation were also found to be suitable. The proposed method can hence be successfully applied to quantify brinzolamide and brimonidine during quality control of formulation.

Novel Simultaneous Identification of Capsaicin and It’s Quantification in Transferosome Formulation By HP-TLC Technique

Introduction: Capsaicin (8-methy-N-vanillyl-6-nonenamide), a potential analgesic derived from Capsicum annuum (Chili peppers), widely used from ancient times for its pharmacological activities such as anti-inflammatory, anti-oxidant and analgesic and provides relief from migraine and diabetes. But for obvious reasons, capsaicin cannot be administered directly. The present work was designed with a focus to comply with mandatory requirement in various pharmacopeias to know the actual content of API present in final formulations. The formulation (TS3) consisting of 3% lipid, with 4:6 ratio of the polymer and solvent, was found to be the optimized formulation, which gave the best evaluation with regard to the particle size (97.03±2.68) nm, polydispersity index (0.20±0.00), higher zeta potential (61.28±2.06) mv, morphological studies and highest drug entrapment efficiency (68.34±4.24)%. The prepared transferosome formulation was subjected to characterization by validated HP-TLC method consisting of N-Hexane: Tert- Iso-butyl-methyl ether in ratio (5:15) v/v. Linearity was performed in the range of 50-1500 ng/spot with LOD/LOQ 50 ng and 150 ng, with regression analysis (R) of 99.91%. Recovery analysis was performed at 3 different levels at 80, 100 and 120 with an average recovery of 106.97%, respectively. Till now, no analytical method has been reported, associated with the characterization of pharmaceutical nano-forms (Capsaicin), like transferosomes. Thus, the maiden validated HP-TLC method for concurrent analysis of capsaicin as API in nano-transferosome may be employed in process quality control of formulations containing the said API. Background: The irritability and adverse effects post application, leading to inflammation and neural pain at the site of administration of newly Capsaicin API and its chemical entities and marketed formulations are usually related to poor permeability, leading to drug complex reactions in the development phases or therapeutic failure along with the quantification of the same in blood plasma. However, advancement in drug formulations with the use of polymer: alcohol ratio and modernized analytical techniques for the quantification of Pharmaceutical APIs seems to be emerging and promising for overcoming pain and related inflammatory complications by formulating the APIs in Transferosome formulation with Validated HP-TLC technique being used as an effective economic and precise tool for quantitative analysis of APIs in their respective nano-forms. Objective: The study proposes a novel standardized method development and validation of pharmaceutical nanoforms with Capsaicin as API. Method: Capsaicin Transferosomes were formulated using Ultra probe sonication by utilizing different proportions of phospholipid 90G dissolved in a mixture of ethanol and propylene glycol. The formulation was subjected to Dynamic Light Scattering (DLS) technique for nano-particle analysis followed by characterization with respect to particle size, polydispersity index, zeta potential and entrapment efficiency. The morphological study of vesicles was determined using SEM and TEM. A Validated HP-TLC method for the identification and determination of Capsaicin in transferosomes formulation was performed as per the ICH guidelines. Results: The formulation gave the best evaluation for particle size (97.03±2.68) nm, polydispersity index (0.20±0.00), higher zeta potential (61.28±2.06) mv, morphological studies (SEM & TEM) and highest drug entrapment efficiency (68.34±4.24)%. DSC thermograms and FTIR spectral patterns confirmed no physical interaction by polymers with API. The prepared formulation was then characterized using HP-TLC method. The best resolution was found in NHexane: Tert-Isobutyl methyl ether in a ratio of 5:15 v/v. The Rf was found to be 0.3±0.03. Linearity was performed in a range of 50-1500 ng/spot, with regression analysis (R) of 99.91% Further, recovery analysis was done at 3 different levels as 80, 100 and 120 with an average recovery of 106.97%. The LOD/LOQ was found to be 50 and 150 ng, respectively. Precision was carried out in which % RSD was found to be precise and accurate. Conclusion: The outcomes of the present study suggested that the proposed novel formulation analyzed by Validated planar chromatographic technique (HP-TLC) for Capsaicin quantification in nanoforms may be employed as a routine quality control method for the said API in various other formulations.

Buclizine crystal forms: First Structural Determinations, counter-ion stoichiometry, hydration, and physicochemical properties of pharmaceutical relevance.

Buclizine (BCZ) is a chiral synthetic piperazine derivative which has antihistaminic, anti-muscarinic and antiemetic properties, and has been reintroduced as an appetite stimulant, especially for pediatric patients. Structural information about this drug, as well as other buclizine crystalline forms (solvates, salts and co-crystals) including the BCZ free-base (BCZ-FB), is non-existent. Here, we present for the first time the crystal structure of the monohydrochloride monohydrate salt of BCZ (BCZHCl·H2O), and of its anhydrous form, BCZHCl. Interestingly, BCZHCl·H2O was obtained by recrystallization from the raw material (BCZH2Cl2) in ethanol:water solution showing that BCZ anhydrous dihydrochloride salt changes easily to a monohydrochloride monohydrate salt modification, which raise concerns about formulation quality control. BCZHCl·H2O and BCZHCl crystallize in the orthorhombic space groups (Pna21 and Pca21) belonging to the mm2 point group and are thus classified as non-centrosymmetric achiral structures (NA). Intuitively, we expect these salts to crystallize in a space group with a center of symmetry, since less than 5% of the known racemic compounds crystallize in the NA type. The crystal structures of BCZH2Cl2 and BCZ-FB were not determined, but their existence was verified by other techniques (chloride ion analysis, PXRD, HPLC, FT-IR, DSC, TGA) and by comparison of the obtained results with those found for BCZHCl. Additionally, we have also performed an evaluation of the equilibrium solubility (at six different aqueous media) and the dissolution profile of the BCZHCl salt compared to the raw material and BCZ-FB. Different equilibrium solubility values were found comparing the three forms in acidic and neutral pH ranges and all of them were insoluble at pH>7.0. Moreover, tablets prepared with BCZH2Cl2, BCZHCl or BCZ-FB show significant differences in terms of dissolution profile.

Pharmaceutical compounding of orphan active ingredients in Belgium: how community and hospital pharmacists can address the needs of patients with rare diseases

BackgroundPharmaceutical compounding of orphan active ingredients can offer cost-effective treatment to patients when no other drug product is available for a rare disease or during periods of drug product shortages. Additionally, it allows customized therapy for patients with rare diseases. However, standardized compounding formulas and procedures, and monographs are required to ensure the patients’ safety.ResultsStandardized formulas and compounding procedures were developed for seven orphan active ingredients (L-arginine, sodium benzoate, sodium phenylbutyrate, L-carnitine, chenodesoxycholic acid, primaquine phosphate, pyridoxal phosphate) and one non-orphan molecule (sodium perchlorate) regularly compounded by hospital pharmacists for extemporaneous use. The stability of these formulations was evaluated over 3 months at refrigerated (5 °C) and standard storage conditions (25 °C/60%RH) using HPLC-based assays and a suitable shelf life was assigned to the formulations. Additionally, suitable analytical methods for quality control of formulations of pyridoxal phosphate and sodium perchlorate were developed as monographs for these components were not available in the European Pharmacopeia or United States Pharmacopeia.ConclusionsAvailability of compounding formulas and protocols, as well as stability information, for orphan active ingredients can improve patients’ access to treatment for rare diseases. Such data were collected for seven orphan active ingredients to treat patients with rare diseases when no other treatment is available. More efforts are needed to develop standardized formulas and compounding procedures for additional orphan active ingredients whose clinical efficacy is well-known but which are not available as products with a marketing authorization. Additionally, a legal framework at EU level is required to enable the full potential of pharmaceutical compounding for orphan active ingredients.

Characterization of branched poly(lactide-co-glycolide) polymers used in injectable, long-acting formulations

Poly(lactide-co-glycolide) (PLGA) has been used in many injectable, long-acting depot formulations. Despite frequent use of PLGA, however, its characterization has been limited to measuring its molecular weight, lactide:glycolide (L:G) ratio, and end-group. These conventional methods are not adequate for characterization of unique PLGA polymers, such as branched PLGA. Glucose-initiated PLGA (Glu-PLGA) has been used in Sandostatin® LAR Depot (octreotide acetate for injectable suspension) approved by the U.S. Food and Drug Administration (FDA) in 1998. Glu-PLGA is a branched (also known as star-shaped) polymer and determining its properties has been challenging. It is necessary to develop methods that can determine and characterize the branching parameters of Glu-PLGA. Such characterization is important not only for the quality control of formulations, but also for developing generic parenteral formulations that are required to have the same excipients in the same amount (qualitative/quantitative (Q1/Q2) sameness) as their Reference Listed Drug (RLD).In this study, an analytical technique was developed and validated using a series of branched-PLGA standards, and it was used to determine the branching parameters of Glu-PLGA extracted from Sandostatin LAR, as well as Glu-PLGAs obtained from three different manufacturers. The analytical technique was based on gel-permeation-chromatography with quadruple detection systems (GPC-4D). GPC-4D enabled characterization of Glu-PLGA in its concentration, absolute molecular weight, hydrodynamic radius and intrinsic viscosity. The plot of the branch units per molecule as a function of molar mass provides a unique profile of each branched PLGA. The Mark-Houwink plots were also used to distinguish different Glu-PLGAs. These ensemble identification methods indicate that the branch units of Glu-PLGAs extracted from Sandostatin LAR range from 2 (i.e., linear) at the lower end of the molecular weight to <4 for the majority (94%) of Glu-PLGA.

Predicting oral disintegrating tablet formulations by neural network techniques

Oral disintegrating tablets (ODTs) are a novel dosage form that can Peer review under responsibility of Shenyang Pharmaceutical University. be dissolved on the tongue within 3 min or less especially for geriatric and pediatric patients. Current ODT formulation studies usually rely on the personal experience of pharmaceutical experts and trial-and-error in the laboratory, which is inefficient and time-consuming. The aim of current research was to establish the prediction model of ODT formulations with direct compression process by artificial neural network (ANN) and deep neural network (DNN) techniques. 145 formulation data were extracted from Web of Science. All datasets were divided into three parts: training set (105 data), validation set (20) and testing set (20). ANN and DNN were compared for the prediction of the disintegrating time. The accuracy of the ANN model have reached 85.60%, 80.00% and 75.00% on the training set, validation set and testing set respectively, whereas that of the DNN model were 85.60%, 85.00% and 80.00%, respectively. Compared with the ANN, DNN showed the better prediction for ODT formulations. It is the first time that deep neural network with the improved dataset selection algorithm is applied to formulation prediction on small data. The proposed predictive approach could evaluate the critical parameters about quality control of formulation, and guide research and process development. The implementation of this prediction model could effectively reduce drug product development timeline and material usage, and proactively facilitate the development of a robust drug product.

Advanced Applications of Raman Imaging for Deeper Understanding and Better Quality Control of Formulations.

The importance of using the Raman imaging technique is increasing in pharmaceutical sciences, particularly in the quality control of active pharmaceutical ingredients, formulation design, and manufacturing development. Formulation design based on Raman imaging data is important for achieving quality by design. Recently, several novel Raman imaging measurement and analytical techniques have been reported. It is undoubtedly essential for pharmaceutical researchers and manufacturing engineers to use modern Raman imaging technology to produce the best quality pharmaceutical products. This short review seeks to inform researchers and engineers about recent developments in Raman imaging techniques applicable to formulation design and manufacturing.

Selection of Optimum Parameters for Separating Amino Acids in a Thin Layer of Sorbent

A theoretical approach to selecting the optimal conditions for separating various amino acids in thin sorbent layers is demonstrated, i.e., the ability to predict R f values from the equations for linear relationships when the polarity of the eluant is known. For simultaneous assays, the optimum values of R f and the best separations are obtained by working with systems in the range 5.13 – 5.69 polarity units. The relationships found in the study can be used to develop various methods which, depending on the aims of the analysis and the suspected amino acid composition, will find use in quality control of formulations containing both single and multiple amino acids and fourth-generation vitamin complexes, as well as for separating and identifying free amino acids present in the raw materials for medicinal herbs and phytopreparations.

Validation and Experimental Design Assisted Robustness Testing of RPLC Method for the Simultaneous Analysis of Brinzolamide and Brimonidine Tartrate in an Ophthalmic Dosage Form

A high performance liquid chromatographic method was developed and validated for the quantitative determination of brinzolamide and brimonidinetartrate. Employing an isocratic RP-HPLC Phenomenex C18 (5 μm, 250×4.6 mm) column resulted in an adequate separation for brinzolamideand brimonidine tartrate with retention time of 5.7±0.345 and 3.8±0.568 min, respectively. Best resolution was achieved with the phosphate buffer (pH 6.6):acetonitrile:methanol (45:15:40) as mobile phase pumped at the flow rate of 1.0 ml/min with the detection wavelength of 254 nm. Regression coefficient for both brinzolamide and brimonidine tartrate was found to be 0.9993 and 0.9965, respectively indicating linearity within the concentration range. Fractional factorial design, 24-1 was applied to assess the robustness of the developed method. Various independent variables selected for robustness testing were wavelength, acetonitrile volume in the mobile phase, flowrate and pH of the mobile phase. It was statistically evinced that retention time of drugs without the loss of resolution between two drugs, is affected by varying the independent variables flow rate and acetonitrile volume in the mobile phase from minimum to maximum. Hence, the limits must be strictly defined for the method conditions; flow rate and acetonitrile volume in mobile phase for optimum separation of drugs with acceptable retention time and resolution. The validation parameters like linearity, precision, accuracy, limit of detection and limit of quantitation were also found to be suitable. The proposed method can hence be successfully applied to quantify brinzolamide and brimonidine tartrate during quality control of formulation.

A high performance thin layer chromatographic method for the estimation of colchicine in different formulations.

Background:Colchicine is a main alkaloid present in bitter and sweet variety of colchicum (Colchicum luteum Baker), which have been reported to possess anti-rheumatic, anti-gout, and anticancer potential. Colchicum is an important ingredient of several Unani and Herbal formulations. Quantification of colchicine will play a great role in quality control of these formulations. Hence, a high-performance thin layer chromatographic (TLC) method has been developed for the analysis of colchicine in Unani formulations of various dosage forms such as hubb (tablet) and capsules.Materials and Methods:The samples were applied on aluminum TLC plates precoated with silica gel 60-F254 and developed using mobile phase toluene-dichloromethane-methanol in equal proportions. Quantification was done by densitometric scanning at 350 nm, which showed a linear response in the range of 50–500 ng/spot. The developed method was validated as per the International Conference on Harmonization guidelines for linearity, precision, accuracy, specificity, robustness, limit of detection, and limit of quantification.Results and Conclusion:The developed method was applied for quantitative estimation of colchicine in different Unani and Herbal formulations. The method was found simple, selective, accurate with a wide range of linearity, hence suitable for the quality control of different formulations and varieties of colchicum with respect to colchicine content.