United States Pharmacopeia-National Formulary Research Articles

Emerging techniques for the trace elemental analysis of plants and food-based extracts: A comprehensive review

This comprehensive review investigates the dynamic landscape of trace elemental analysis methodologies applied to plants and food-based extracts. The exploration spans from the inception of techniques to the latest procedures, contributing to heightened precision and sensitivity in elemental detection. According to the WHO, herbal plants and medicine from varied soil compositions serve as crucial therapeutic agents for 70–80 % of the world's population. Yet, their susceptibility to trace element toxicity poses a significant risk to human health. Rising population and increased food demands have led to environmental pollution, contaminating the food chain through unintended activities like industrialization, mining, and pesticide production. The elemental composition of plants and derived extracts is central to comprehending nutritional profiles, evaluating product quality, and ensuring food safety. Methodological advancements, progressing from manual procedures to sophisticated technologies such as X-ray fluorescence (XRF), neutron activation analysis (NAA), inductively coupled plasma optical emission spectroscopy (ICP OES), and inductively coupled plasma mass spectrometry (ICP-MS), are delineated. Recent strides in paper-based electrochemical sensors are highlighted for their distinctive capabilities and elucidation of associated advantages and limitations.Moreover, the review delves into innovative sample preparation methodologies, encompassing microwave-assisted digestion and solid-phase microextraction, to amplify the efficiency of elemental extraction and subsequent analysis. Integrating data analytics and machine learning in elucidating complex elementary datasets is explored, underscoring the potential for heightened accuracy and automation in trace elemental analysis. This review compiles literature data, summarizing sample preparation methods for various herbal parts (roots, soil, stems, bark, fruits, food). Standard protocols from WHO, United States Pharmacopeia-National Formulary (USP-FR), Ayurveda, Yoga and Naturopathy, Unani, Siddha, and Homeopathy (AYUSH) are considered. Lead, Cadmium, Mercury, and Arsenic are the primary toxic elements of concern in herbal medicines. This review furnishes valuable insights tailored for researchers, analysts, and policymakers actively involved in advancing the domain of trace elemental analysis in plants and food-based extract.

Analytical method development, validation, and out-of-specification investigations for polyethylene glycol

This work was motivated by the United States Pharmacopeia monograph modernization initiative and European directorate for the quality of medicines and healthcare. An out-of-specification (OOS) occurrence prompted OOS investigations for the cGMP (cGMP refers to the Current Good Manufacturing Practice regulations enforced by the FDA) release testing of residual ethylene oxide in polyethylene glycol (PEG) according to the standards detailed within the United States Pharmacopeia/National Formulary (USP-NF) for polyethylene glycol, and the European Pharmacopoeia (Ph. Eur.) for macrogols. During the OOS root cause investigations, we observed a PEG degradant and identified it as methyl formate, which co-elutes with ethylene oxide using the GC (gas chromatography) methods published in current USP-NF and Ph. Eur. for PEGs. To address this, a novel method utilizing static headspace gas chromatography with flame ionization detection (HS-GC-FID) was developed to test various grades of PEGs for the presence of residual ethylene oxide, along with other process related impurities and degradation products. With this new method, ethylene oxide, a known genotoxic impurity and IARC (International Agency for Research on Cancer) Class 1 human carcinogen, can be well resolved from methyl formate, a newly identified and comparatively innocuous degradant derived from PEG. The currently available official compendial methods are unable to separate the specific impurities in PEGs. However, the new GC method presented in this paper has been shown to have a high and unique selectivity, allowing for baseline separations (chromatographic resolutions greater than 1.5) of all related impurities in PEGs, which is a challenging task. Additionally, this method has been found to be stability-indicating based on a forced degradation study. During stress stability study of PEGs involving acid, alkali, heat, light, and oxidation, some other PEG degradants, including formaldehyde, were identified. It is possible that formaldehyde undergoes a disproportionation reaction known as the Cannizzaro reaction, leading to the formation of formic acid and methanol. The formic acid then undergoes an esterification reaction with methanol to produce methyl formate. To the best of our knowledge, this is the first stability-indicating HS-GC-FID method that accomplishes this separation in a single run, and it was successfully validated as per ICH (the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use) guidelines. Therefore, this method is suitable for the conduct of cGMP batch release and stability testing of PEGs in regulated quality control (QC) laboratories.

Spectroscopy and Spectroscopic Analytical Techniques in the United States Pharmacopeia–National Formulary (USP–NF)

The U.S. Pharmacopeia (USP) is a non-profit scientific organization whose mission is to improve global public health through public standards and related programs that ensure the quality, safety and benefits of medicines and foods. Vibrational spectroscopy is an analytical tool that is used in the United States Pharmacopeia and National Formulary (USP–NF) and has been since the 1950s. We explain the organization of the documentation within the USP–NF and how vibrational spectroscopy plays an important role in this regulatory document collection.

Recommendations on the quantitative analysis of pheophorbides, photosensitizers present in algal biomass intended as food supplement

Pheophorbide a is the major photosensitizer present in algal biomass and its presence in food supplement was linked to human health issues in the past. Although several pheophorbide a quantification methods have been proposed including the United States Pharmacopeia-National Formulary protocol (USP-NFP), there are open methodological issues which make their results questionable. In the present study we have tested optimal extraction conditions for pheophorbide a from a disintegrated biomass of green algae Chlorella and Haematococcus, widely used as food supplement. Further we have compared the quantification of pheophorbide a in algal extracts using HPLC-HRMS with the spectrophotometric quantification after USP-NFP in Haematococcus biomass and oleoresin samples. We have demonstrated that USP-NFP provide considerably (1.7–2.4 times) higher pheophorbide contents compared to HPLC-HRMS quantification using a pheophorbide a analytical standard. This was mainly caused by the fact that USP-NFP integrates the concentration of all pheophorbide variants present in the samples. We have detected nine pheophorbide analogues in the original algal sample as well as in the final sample of USP-NFP, of which pheophorbide a represented only ~40%. However, this explains the values obtained by USP-NFP only partly. We also show that 60% acetone is the most suitable extraction solvent for pheophorbide a from various algal samples; however, we noted that such extracts might exhibit high activity of chlorophyllase generating pheophorbide a during the extraction process. This activity differed between studied Chlorella and Haematococcus biomass extracts. We have achieved the chlorophyllase inactivation by a short-term high-temperature treatment (90 °C, 5 min). Acceptable stability of pheophorbide a and only minor degradation of chlorophyll to pheophorbide a has been observed at these conditions.This study demonstrates the need for 1) an HPLC-DAD-based method employing multiple pheophorbide standards and 2) involvement of chlorophyllase inactivation protocol, to ensure proper quantification of pheophorbide content in algal biomass.

Development of a Logic Model for Promoting Incorporation of the Concepts of Impurity-Related ICH Guidelines into Pharmacopoeias Based on Cause and Effect Analysis.

In line with the recent globalization of the drug supply chain and promotion of the use of generic drugs worldwide, quality assurance is required for drugs globally. In particular, controlling impurities is one of the biggest areas of interest regarding pharmaceutical quality, and it is desirable that the latest scientific standards harmonized in the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) are not only implemented in approval applications but also incorporated in pharmacopoeias which are public standards to ensure pharmaceutical quality more widely. However, incorporation into a pharmacopoeia takes time because careful consideration is required owing to the characteristics of a pharmacopoeia that is widely used for drugs, including those already on the market. To consider a smooth approach for the incorporation, we retrospectively examined approaches to incorporate the concepts of the ICH Q3C, Q3D, and M7 guidelines covering residual solvents, elemental impurities, and mutagenic impurities which are particularly toxic impurities into the European Pharmacopoeia, United States Pharmacopeia-National Formulary, and Japanese Pharmacopoeia, with approaches to implement these guidelines into approval processes in Europe, the U.S., and Japan. We also identified barriers and facilitators to this goal via cause and effect analysis. Moreover, we developed a logic model for the smooth incorporation of the concepts of impurity-related ICH guidelines. We expect that our proposed approach will be applied as a framework to smoothly incorporate the results of international harmonization activities for controlling impurities into each pharmacopoeia.

Isolation and Ultra-Purification of Oleic Acid Extracted from Olive Oil Using Urea Crystallization

Oleic acid is an omega-9 fatty acid that is found naturally in many vegetable sources and animal products The major component in olive oil is the triglyceride esters of oleic acid. This triglyceride is one of the sources of good cholesterol. Oleic acid USP-NF (United States Pharmacopeia-National Formulary) material is a common pharmaceutical excipient that has been widely used in various dosage forms. In this paper we are describing a method for isolation and purification oleic acid in a high purity 99% from fatty acids extracted from olive oil in coastal region of Syria by selectively using urea addition crystallization and cooling crystallization. A gas chromatography-flame ionization detection (GC-FID) method was used for direct quantitative analysis of oleic acid and related fatty acids in oleic acid USP-NF material.

Structural confirmation of sulconazole sulfoxide as the primary degradation product of sulconazole nitrate

Sulconazole has been reported to degrade into sulconazole sulfoxide via sulfur oxidation; however, structural characterization data was lacking and the potential formation of an N-oxide or sulfone could not be excluded. To clarify the degradation pathways and incorporate the impurity profile of sulconazole into the United States Pharmacopeia–National Formulary (USP–NF) monographs, a multifaceted approach was utilized to confirm the identity of the degradant. The approach combines stress testing of sulconazole nitrate, chemical synthesis of the degradant via a hydrogen peroxide-mediated oxidation reaction, semi-preparative HPLC purification, and structural elucidation by LC–MS/MS and NMR spectroscopy. Structural determination was primarily based on the comparison of spectroscopic data of sulconazole and the oxidative degradant. The mass spectrometric data have revealed a McLafferty-type rearrangement as the characteristic fragmentation pathway for alkyl sulfoxides with a β-hydrogen atom, and was used to distinguish the sulfoxide from N-oxide or sulfone derivatives. Moreover, the generated sulconazole sulfoxide was utilized as reference material for compendial procedure development and validation, which provides support for USP monograph modernization.

Overregulation Revisited

To the Editor The Atchabahian and Boublik1 quotes from USP 797, “Pharmaceutical Compounding – Sterile Preparations” in the United States Pharmacopeia National Formulary, only apply to compounded sterile preparations and are not applicable to simple intravenous (IV) and arterial line setups. Morey’s2 statement, “Currently, arterial line setups must be used within an hour of preparation, preventing health care providers from having a setup ready for the patient. According to the USP 797 guidelines, ‘sterile contents of commercially manufactured products’ such as an arterial line setup that are created in ‘room air quality worse than ISO [International Organization for Standardization] Class 5’ are considered ‘contaminated or at high risk to become contaminated’ if they are not used within 1 hour” is incorrect. USP 797 only refers to pharmaceutical compounding of sterile preparations. Because commercially prepared arterial line flush solutions and IV solutions are not compounded, these preparations are not subject to time limits between spiking and use. The important distinction here is that the simple spiking of a sterile, commercially prepared solution should not be confused with compounding. A personal communication from USP chief liaison officer for chapter 797, Rick Schnatz, PharmD, verified that USP 797 refers solely to compounded preparations and not the simple spiking of manufactured sterile products. If we were to accept the notion that an IV or arterial line flush bag becomes contaminated 1 hour after spiking, then we must accept that time-dependent contamination would also continue after the IV or arterial line has been attached to a patient. By that reasoning, all IV and arterial line setups should be replaced every hour. This simple, and unfortunately common misunderstanding of USP 797, may have led and could lead to unnecessary, costly, and burdensome overregulation by well-intended hospital administrators unless it is stopped. As an example at our institution, the administration proposed a more than $1 million facilities modification to create an ISO class 5 clean room in the operating area. This room was to be dedicated solely to spiking IV bags and arterial line setups. After several meetings and email exchanges, reason eventually prevailed. An overzealous and misguided administration can needlessly increase operational expense while simultaneously decreasing operational efficiency with no benefit to patient care. John G. Brock-Utne, MD, PhDDepartment of Anesthesiology, Perioperative & Pain MedicineStanford University School of MedicineStanford, California[email protected] Joseph Sanford, MDDepartment of AnesthesiologyUniversity of Arkansas for Medical SciencesLittle Rock, Arkansas Richard A. Jaffe, MD, PhDDepartment of Anesthesiology, Perioperative & Pain MedicineStanford University School of MedicineStanford, California

Performance Equivalence and Validation of the Soleris Automated System for Quantitative Microbial Content Testing Using Pure Suspension Cultures.

Using United States Pharmacopeia-National Formulary (USP-NF) general method <1223> guidance, the Soleris(®) automated system and reagents (Nonfermenting Total Viable Count for bacteria and Direct Yeast and Mold for yeast and mold) were validated, using a performance equivalence approach, as an alternative to plate counting for total microbial content analysis using five representative microbes: Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Candida albicans, and Aspergillus brasiliensis. Detection times (DTs) in the alternative automated system were linearly correlated to CFU/sample (R(2) = 0.94-0.97) with ≥70% accuracy per USP General Chapter <1223> guidance. The LOD and LOQ of the automated system were statistically similar to the traditional plate count method. This system was significantly more precise than plate counting (RSD 1.2-2.9% for DT, 7.8-40.6% for plate counts), was statistically comparable to plate counting with respect to variations in analyst, vial lots, and instruments, and was robust when variations in the operating detection thresholds (dTs; ±2 units) were used. The automated system produced accurate results, was more precise and less labor-intensive, and met or exceeded criteria for a valid alternative quantitative method, consistent with USP-NF general method <1223> guidance.

Dietary supplements quality analysis tools from the United States Pharmacopeia.

The United States Food and Drug Administration (FDA) issued the dietary supplement (DS) current good manufacturing practice (GMP) regulations in compliance with the mandate from the Dietary Supplements Health and Education Act (DSHEA), with the intention of protecting public health by ensuring the quality of DS. The GMP regulations require manufacturers to establish their own quality specifications for identity, purity, strength, composition, and absence of contaminants. Numerous FDA‐conducted GMP inspections found that the private specifications set by these manufacturers are often insufficient to ensure adequate quality of dietary ingredients and DS. Wider use of the public standards developed by the United States Pharmacopeial Convention (USP), in conjunction with GMP compliance, can help ensure quality and consistency of DS as they do for medicines. Public health protection could be enhanced by strengthening the GMP provisions to require conformance with relevant United States Pharmacopeia–National Formulary (USP–NF) standards, or in the absence of USP standards, other public compendial standards. Another serious concern is the presence of synthetic drugs and drug analogues in products marketed as DS. Use of the new USP General Chapter Adulteration of Dietary Supplements with Drugs and Drug Analogs <2251> may reduce the exposure of consumers to dangerous drugs disguised as DS. © 2016 The Authors. Drug Testing and Analysis published by John Wiley & Sons Ltd.

Development and validation of a hydrophilic interaction chromatography method coupled with a charged aerosol detector for quantitative analysis of nonchromophoric α–hydroxyamines, organic impurities of metoprolol

The European Pharmacopeia (EP) metoprolol impurities M and N are polar, nonchromophoric α-hydroxyamines, which are poorly retained in a conventional reversed-phase chromatographic system and are invisible for UV detection. Impurities M and N are currently analyzed by TLC methods in the EP as specified impurities and in the United States Pharmacopeia-National Formulary (USP-NF) as unspecified impurities. In order to modernize the USP monographs of metoprolol drug substances and related drug products, a hydrophilic interaction chromatography (HILIC) method coupled with a charged aerosol detector (CAD) was explored for the analysis of the two impurities. A comprehensive column screening that covers a variety of HILIC stationary phases (underivatized silica, amide, diol, amino, zwitterionic, polysuccinimide, cyclodextrin, and mixed-mode) and optimization of HPLC conditions led to the identification of a Halo Penta HILIC column (4.6 × 150 mm, 5 μm) and a mobile phase comprising 85% acetonitrile and 15% ammonium formate buffer (100 mM, pH 3.2). Efficient separations of metoprolol, succinic acid, and EP metoprolol impurities M and N were achieved within a short time frame (<8 min). The HILIC-CAD method was subsequently validated per USP validation guidelines with respect to specificity, robustness, linearity, accuracy, and precision, and could be incorporated into the current USP-NF monographs to replace the outdated TLC methods. Furthermore, the developed method was successfully applied to determine organic impurities in metoprolol drug substance (metoprolol succinate) and drug products (metoprolol tartrate injection and metoprolol succinate extended release tablets).

Development and validation of a GC–FID method for quantitative analysis of oleic acid and related fatty acids

Oleic acid is a common pharmaceutical excipient that has been widely used in various dosage forms. Gas chromatography (GC) has often been used as the quantitation method for fatty acids normally requiring a derivatization step. The aim of this study was to develop a simple, robust, and derivatization-free GC method that is suitable for routine analysis of all the major components in oleic acid USP-NF (United States Pharmacopeia-National Formulary) material. A gas chromatography–flame ionization detection (GC–FID) method was developed for direct quantitative analysis of oleic acid and related fatty acids in oleic acid USP-NF material. Fifteen fatty acids were separated using a DB-FFAP (nitroterephthalic acid modified polyethylene glycol) capillary GC column (30m×0.32mm i.d.) with a total run time of 20min. The method was validated in terms of specificity, linearity, precision, accuracy, sensitivity, and robustness. The method can be routinely used for the purpose of oleic acid USP-NF material analysis.

Adulteration of Ginkgo biloba products and a simple method to improve its detection

Extracts of ginkgo (Ginkgo biloba) leaf are widely available worldwide in herbal medicinal products, dietary supplements, botanicals and complementary medicines, and several pharmacopoeias contain monographs for ginkgo leaf, leaf extract and finished products. Being a high-value botanical commodity, ginkgo extracts may be the subject of economically motivated adulteration. We analysed eight ginkgo leaf retail products purchased in Australia and Denmark and found compelling evidence of adulteration with flavonol aglycones in three of these. The same three products also contained genistein, an isoflavone that does not occur in ginkgo leaf.Although the United States Pharmacopeia – National Formulary (USP-NF) and the British and European Pharmacopoeias stipulate a required range for flavonol glycosides in ginkgo extract, the prescribed assays quantify flavonol aglycones. This means that these pharmacopoeial methods are not capable of detecting adulteration of ginkgo extract with free flavonol aglycones.We propose a simple modification of the USP-NF method that addresses this problem: by assaying for flavonol aglycones pre and post hydrolysis the content of flavonol glycosides can be accurately estimated via a simple calculation. We also recommend a maximum limit be set for free flavonol aglycones in ginkgo extract.

Overuse of Antidepressants in a Nationally Representative Adult Patient Population in 2005

Objective: Concerns have been raised that antidepressants may be overused. This study aimed to provide an estimate of antidepressant overuse in a more recent, nationally representative sample of adults and with a more contemporary set of antidepressants than has been covered in prior studies. Methods: The data set included adult (weighted N=23,026,608) respondents who self-reported antidepressant treatment in the household and prescription drug components of the 2005 Medical Expenditure Panel Survey. Overuse was defined as off-label antidepressant prescribing with limited or no scientific support for use as a treatment for the diagnosis, according to the Physicians' Desk Reference, the United States Pharmacopeia-National Formulary, and the Micromedex DrugDx data system. Stratification and multivariate logistic regression was used to examine clinical and socioeconomic predictors of overuse. Results: Overuse was estimated at 20%, with the majority concentrated in newer-generation antidepressants (74% of overuse). Another 30%–40% of overuse was associated with documented diagnoses that may represent a reasonable clinical rationale for antidepressant use or suggest underdiagnosis of possible depressive and anxiety syndromes. Older age (odds ratio [OR]=.95, p=.03) and self-report of poor mental health (OR=.80, p=.02) were negatively associated with overuse. Conclusions: Antidepressant overuse among adults is less common than previously reported. Our results suggest that the actual extent of overuse may be lower than 20%. To improve treatment quality and the efficiency of the U.S. health care system, nationally representative data collection efforts on prescription drug use should aim to include enhanced measures of need in order to further refine future estimates of antidepressant overuse. (Psychiatric Services 62:720–726, 2011)

Overuse of antidepressants in a nationally representative adult patient population in 2005.

Concerns have been raised that antidepressants may be overused. This study aimed to provide an estimate of antidepressant overuse in a more recent, nationally representative sample of adults and with a more contemporary set of antidepressants than has been covered in prior studies. The data set included adult (weighted N=23,026,608) respondents who self-reported antidepressant treatment in the household and prescription drug components of the 2005 Medical Expenditure Panel Survey. Overuse was defined as off-label antidepressant prescribing with limited or no scientific support for use as a treatment for the diagnosis, according to the Physicians' Desk Reference, the United States Pharmacopeia-National Formulary, and the Micromedex DrugDx data system. Stratification and multivariate logistic regression was used to examine clinical and socioeconomic predictors of overuse. Overuse was estimated at 20%, with the majority concentrated in newer-generation antidepressants (74% of overuse). Another 30%-40% of overuse was associated with documented diagnoses that may represent a reasonable clinical rationale for antidepressant use or suggest underdiagnosis of possible depressive and anxiety syndromes. Older age (odds ratio [OR]=.95, p=.03) and self-report of poor mental health (OR=.80, p=.02) were negatively associated with overuse. Antidepressant overuse among adults is less common than previously reported. Our results suggest that the actual extent of overuse may be lower than 20%. To improve treatment quality and the efficiency of the U.S. health care system, nationally representative data collection efforts on prescription drug use should aim to include enhanced measures of need in order to further refine future estimates of antidepressant overuse.

Chemical Stability of Hydrocortisone in Topical Preparation in Proprietary VersaPro™ Cream Base

The United States Pharmacopeia-National Formulary (USP-NF) suggests beyond use dating ((BUD) for compounded topical preparations containing active pharmaceutical ingredients (API) [1]. The beyond the use dates of the preparations are based on the conservative and empirical guidelines of USP 795. Hydrocortisone (HC) content compounded in the VersaPro™ base cream was quantified using a HPLC method at time zero and after 30 and 60 days of storage at both room temperature and 4°C. The analysis suggests that the compounded preparations retain &gt; 95% of the stated initial potency of HC regardless of storage conditions. Thus HC creams prepared in VersaPro™ cream base can be safely assigned a beyond the use date of two months when stored at room temperature.&#x0D; &#x0D; Type: Original Research

US pharmacopeia council of experts 2005–2010: Work plans, new revision approaches, and other enhancements

The United States Pharmacopeial Convention (the USP Convention), which meets at 5-year intervals, last convened in 2005. At that meeting, the Convention membership elected a new Council of Experts for the 2005-2010 cycle. In turn, the Council elected members of Expert Committees charged with updating and revising the United States Pharmacopeia-National Formulary (USP-NF) and developing other authoritative standards and information. As one of their final activities, Expert Committees from the 2000-2005 cycle and USP staff carefully reviewed their work from the 2000-2005 cycle and reexamined the contents of USP-NF. From this comprehensive inventory emerged an updated and more focused new work plan directed toward acquiring missing monographs, updating monographs (typically because of advances in analytical technologies), and attending to General Chapter work (eg, dividing the General Chapter Chromatography <621> into smaller chapters) during the 2005-2010 cycle. Several elements of the work plan also speak to Resolutions adopted at the March 2005 Convention (available at www.usp.org/aboutUSP/resolutions.html) and prior ones as well. Because the work plan involves new approaches that affect both General Chapters (and thus the performance of tests and procedures) and monograph specifications--as well as the function of Pharmacopeial Forum and the introduction of new products--USP expects the plan to have a broad impact. This article briefly reviews some of these anticipated changes, informs constituents about how they can remain updated about progress and upcoming modifications to official texts, and invites participation in the standards-setting process.

Equivalence studies for complex active ingredients and dosage forms

This article examines the United States Pharmacopeia (USP) and its role in assessing the equivalence and inequivalence of biological and biotechnological drug substances and products-a role USP has played since its founding in 1820. A public monograph in the United States Pharmacopeia-National Formulary helps practitioners and other interested parties understand how an article's strength, quality, and purity should be controlled. Such a monograph is a standard to which all manufactured ingredients and products should conform, and it is a starting point for subsequent-entry manufacturers, recognizing that substantial additional one-time characterization studies may be needed to document equivalence. Review of these studies is the province of the regulatory agency, but compendial tests can provide clarity and guidance in the process.

TLC SEPARATION AND IDENTIFICATION OF NEOMYCIN SULFATE, POLYMYXIN B SULFATE, AND BACITRACIN ZINC IN OINTMENTS

The development of a thin-layer chromatography method for the separation and identification of polymyxin B sulfate, neomycin sulfate, and bacitracin zinc in ointments, either alone or in combinations, is described. The ointments were dispersed in chloroform and the components of interest were extracted into an aqueous 0.1 N hydrochloric acid layer. The stationary phase was silica gel G and the mobile phase consisted of a mixture of methanol, ethanol, methylene chloride, ammonium hydroxide, and water (3 : 3 : 2 : 2 : 1.5, v/v) or methanol, isopropanol, methylene chloride, ammonium hydroxide, and water (4 : 2 : 2 : 2 : 1.5, v/v). Detection was performed by spraying with a 0.2% solution of ninhydrin in 1-butanol. A number of commercial samples were analyzed using the described method. Our method worked on all brands tested, except one brand of the three-component ointment (Brand A), which contained interfering excipients. A sample clean-up step was developed to remove the interferences. The method described was compared to the official methods described in the United States Pharmacopeia-National Formulary (USP24-NF19). Our method offered much better separation and well-defined spots compared to the official methods.