非法冰毒晶体中有机杂质的气相色谱-质谱分析

建立了一种适用于分析冰毒杂质的方法,并分析其形成原因。将冰毒样品溶于1 mL 0.1 mol/L pH7.0的磷酸盐缓冲液(4份缓冲液1份10%Na2CO3),杂质用0.5 mL乙酸乙酯萃取。结果共有8种物质被检出。N-甲酰甲基安非他明、N-乙酰甲基安非他明在样品中出现,说明此批冰毒由苯丙酮(phenyl-2-propanone,P-2-P)经Leuckart法合成。N-乙基甲基安非他明的检出,则说明用于合成此批冰毒的P-2-P由苯甲醛和硝基乙烷合成。从实验结果看,该法可以满足冰毒杂质分析的需要,为分析冰毒杂质成分的成因、判断冰毒样品的合成路径提供重要信息。     

Quantitative thin-layer chromatographic method of analysis of azithromycin in pure and capsule forms

A validated stability-indicating thin-layer chromatographic (TLC) method of the analysis of azithromycin (AZT) in bulk and capsule forms is developed. Both AZT potential impurity and degradation products can be selectively and accurately estimated in both raw material and product onto one precoated silica-gel TLC plate 60F254. The development system used is n-hexane-ethyl acetate-diethylamine (75:25:10, v/v/v). The separated bands are detected as brown to brownish red spots after spraying with modified Dragendorff's solution. The Rf values of AZT, azaerythromycin A, and the three degradation products are 0.54, 0.35, 0.40, 0.20, and 0.12, respectively. The optical densities of the separated spots are found to be linear in proportion to the amount used. The stress testing of AZT shows that azaerythromycin A is the major impurity and degradation product, accompanied by three other unknown degradation products. The stability of AZT is studied under accelerated conditions in order to provide a rapid indication of differences that might result from a change in the manufacturing process or source of the sample. The forced degradation conditions include the effect of heat, moisture, light, acid-base hydrolysis, sonication, and oxidation. The compatibility of AZT with the excipients used is also studied in the presence and absence of moisture. The amounts of AZT and azaerythromycin A are calculated from the corresponding linear calibration curve; however, the amounts of any other generated or detected unknown impurities are calculated as if it were AZT. This method shows enough selectivity, sensitivity, accuracy, precision, linearity-range, and robustness to satisfy Federal Drug Administration/International Conference of Harmonization regulatory requirements. The method developed can also be used for the purity testing of AZT raw material and capsules, content uniformity testing, dissolution testing, and stability testing of AZT capsules. The potential impurity profiles of both active AZT material and capsule forms are found comparable. The linear range of AZT is between 5 and 30 mcg/spot with a limit of quantitation of 2 mcg/spot. The intraassay relative standard deviation percentage is not more than 0.54%, and the day-to-day variation is not more than 0.86%, calculated on the amounts of AZT RS recovered using different TLC plates.     

A validated stability-indicating RP-HPLC assay method for Amsacrine and its related substances

A validated specific stability indicating reversed-phase high-performance liquid chromatography method was developed for the quantitative determination of Amsacrine as well as its related substances determination in bulk samples, in presence of degradation products, and its process related impurities. Forced degradation studies were performed on bulk samples of Amsacrine as per International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human use (ICH) prescribed stress conditions using acid, base, oxidative, thermal stress, and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed during basic hydrolysis, slight degradation was observed in oxidative and thermal stress, and no degradation was observed in other stress conditions. The chromatographic method was optimized using the samples generated from forced degradation studies and the impurity spiked solution. Good resolution between the peaks corresponds to process-related impurities and degradation products from the analyte were achieved on Inertsil ODS column using the mobile phase consists a mixture of 1.0% triethyl amine in 20 mM potassium dihydrogen orthophosphate, with pH adjusted to 6.5, with ortho phosphoric acid in water and acetonitrile using a simple linear gradient. The detection was carried out at wavelength 248 nm. The mass balance in each case was in between 99.4% to 99.9%, indicating that the developed method was stability-indicating. Validation of the developed method was carried out as per ICH requirements. The developed method was found to be suitable to check the quality of bulk samples of Amsacrine at the time of batch release and also during its stability studies.     

Impurity profile of macitentan in tablet dosage form using a stability-indicating high performance liquid chromatography method and forced degradation study

Macitentan (MAC) is a pulmonary arterial hypertension (PAH) drug marketed as a tablet and often has stability issues in the final dosage form. Quantitative determination of MAC and its associated impurities in tablet dosage form has not been previously reported. This study quantified impurities present in Macitentan tablets using a binary solvent-based gradient elution method using reversed phase-high performance liquid chromatography. The developed method was validated per International Conference on Harmonization (ICH) guidelines and the drug product was subjected to forced degradation studies to evaluate stability. The developed method efficiently separated the drug and impurities (48 min) without interference from solvents, excipients, or other impurities. The developed method met all guidelines in all characteristics with recoveries ranging from 85%-115%, linearity with r² ≥ 0.9966, and substantial robustness. The stability-indicating nature of the method was evaluated using stressed conditions (hydrolysis:1 N HCl at 80℃/15 min; 1 N NaOH at 25℃/45 min; humidity stress (90% relative humidity) at 25℃ for 24 h, oxidation:at 6% (v/v) H₂O₂, 80℃/15 min, thermolysis:at 105℃/16 h and photolysis:UV light at 200 Wh/m²; Fluorescent light at 1.2 million luxh). Forced degradation experiments showed that the developed method was effective for impurity profiling. All stressed samples were assayed and mass balance was>96%. Forced degradation results indicated that MAC tablets were sensitive to hydrolysis (acid and alkali) and thermal conditions. The developed method is suitable for both assay and impurity determination, which is applicable to the pharmaceutical industry.     

An innovative impurity profiling of Avanafil using LC and LC-MS/MS with in-silico toxicity prediction

Degradation of the drug can lead to the formation of toxic substance hence drug quality and stability is a major concern by pharma regulators. A Selected phosphodiesterase type 5 inhibitor drug Avanafil (AV) structure has amide, arylchloro and hydroxide as functional groups which can easily eliminated during hydrolysis. Henceforth, thoroughly chemical stability of AV was carried out according to ICH guideline Q1A (R2). The drug and marketed tablet formulation undergoes degradation in hydrolytic (acid, base, neutral), thermal, photolytic, oxidative conditions and forms a total new sixteen degradation products (D.P.s) which were identified by LC, characterized by LC-MS/MS and probable degradation mechanism for each stress conditions are proposed. All sixteen D.P.s were identified by optimized LC conditions; C18 column using 10 mM ammonium acetate: ACN (60:40, v/v), pH 4.5 as mobile phase at 0.9 mL min⁻¹ of flow rate, 239 nm wavelength at 20 °C column temperature and the method being LC-MS compatible characterized by LC-MS/MS confirmed by relative retention time (RRT). The structure of D.P.s was confirmed from the fragmentation pattern obtained by LC-MS/MS and further probable degradation mechanism for each stress condition is proposed. The drug and its marketed tablet formulation showed similar degradation peaks which were confirmed using RRT, photodiode array (PDA) and LC-MS. Drug degradation happens due to nucleophilic substitution reaction, amide hydrolysis, electron withdrawing properties of amide, dechlorination and bond cleavage due to energy. The amide group in AV structure can undergo hydrolysis, while due to aryl chloride and hydroxide group in structure it undergoes photodecomposition. A comprehensive stress study reveals that AV is more prone to degrade in light, temperature and moisture; hence AV requires proper storage condition temperature below 25 °C with protection to light and moisture. In silico toxicity prediction of physicochemical properties revealed that all the physicochemical parameters of impurities were within the acceptable limit which indicates that no impurity is at any risk of toxicity. In detail, the LC-MS/MS compatible AV degradation study is fully validated as per ICH Q2 (R1) guideline.     

Validatibility of a capillary isoelectric focusing method for impurity quantitation

A strategy is presented for examining the validatability of a capillary isoelectric focusing (cIEF) method, intended for quantitation of product-related impurities in a protein drug substance, according to guidelines published by the International Conference on Harmonization (ICH). The results of this study demonstrate the suitability of cIEF as an analytical method for the quantitation of two product-related impurities in a protein drug substance: a monodeamidated degradation product and an aggregated form of the parent molecule. A range of impurity levels was generated by spiking the isolated impurity species, into a representative production lot of the drug substance. Six impurity spike levels (0.5-12% impurity for deamidated species and 0.5-8% impurity for aggregated species) were analyzed in triplicate. Measurement of impurity peak area percent in the spiked samples provided the data for computing specificity, accuracy, precision, linearity and limit of quantitation (LOQ) for the impurities. Accuracy, defined as the agreement of peak area percent for impurity species with the theoretical impurity percentage from the spike ratio, was 85-96% for the deamidated species and 73-97% for the aggregated species. A linear relationship was found between the measured area percent and the theoretical percent impurity for both impurity species (coefficient of determination, r2=0.9994 for deamidated species and =0.9827 for aggregated species). Precision (repeatability) studies demonstrated a low relative standard deviation (RSD) value (<6%) at all spike levels for both impurity species. Intermediate precision and reproducibility were evaluated by simulating many of the multivariable testing conditions expected during the life cycle of an analytical method, such as multiple equipment and laboratories. Repeated analyses of the drug substance under these varied conditions, yielded RSD values of <20%, for both impurity species. The LOQ, defined as the lowest impurity level where both accuracy and precision were achieved, was assigned at the 0.5% impurity level for both impurity species. This work illustrates a successful strategy in applying the ICH validation guidelines for impurity analytical methods to a cIEF method. Moreover, the data demonstrate the ability of cIEF to be used reliably as an analytical method for impurity quantitation.     

Recognition of Artifacts Occurring in TLC

Abstract

The increased production of drugs requires a concomitant assessment of drug purity. Chromatography in general, and thin layer chromatography in particular, play an important role in determination of the impurity profiles of drug candidates. However, in using chromatography to determine impurities, the chemist must be careful, since extraneous zones or spots do not always indicate impurities. They may instead be artifacts, produced in the chromatographic system. In this paper we present a phenomenon related to on-plate decomposition. MK0912 was chosen as a model compound. To overcome the on-plate degradation an inclusion compound was formed with γ-cyclodextrin in the spotting solution, followed by a mobile phase containing hexadecyltrimethylammonium bromide as a micelle generator. This technique proved to be successful for preventing degradation during chromatography.     

A Validated, Specific Stability-Indicating RP-LC Method for Moxifloxacin and Its Related Substances

A validated, specific, stability-indicating reversed-phase liquid chromatographic method has been developed for quantitative analysis of moxifloxacin and its related substances in bulk samples and pharmaceutical dosage forms in the presence of degradation products and process-related impurities. Forced degradation studies were performed on bulk samples of moxifloxacin, in accordance with ICH guidelines, using acidic, basic, and oxidizing conditions, and thermal and photolytic stress, to show the stability-indicating power of the method. Significant degradation was caused by oxidative stress and by basic conditions; no degradation was observed under the other stress conditions. The method was optimized by analysis of the samples generated during the forced degradation studies and sample solutions spiked with the impurities. Good resolution between the analyte peak and peaks corresponding to process-related impurities and degradation products was achieved on a C₁₈ column with a simple linear mobile phase gradient prepared from aqueous sodium dihydrogen orthophosphate dihydrate containing triethylamine, pH adjusted to 3.0 with orthophosphoric acid, and methanol. Detection was performed at 240 nm. Limits of detection and quantification were established for moxifloxacin and its process related impurities. When the stressed test solutions were assayed against moxifloxacin working standard solution the mass balance was always between 99.3 and 100.1%, indicating the method was stability-indicating. The method was validated in accordance with ICH guidelines, and found to be suitable for checking the quality of bulk samples of moxifloxacin at the time of release of a batch and during storage (long term and accelerated stability testing was conducted).     

氧-水蒸汽中Sr2GdRuO6纯相的合成及固相反应机理

采用氧(或空气)-水蒸汽混合气氛下的固相反应,可合成无任何SrRuO3杂相的纯相化合物Sr2GdRuO6.当由Sr2GdRuO6作先驱物,类似的固相反应体系,可成功合成无任何SrRuO3杂相的纯相RuSr2GdCu2O8化合物.此外,还讨论了有水蒸汽参与的固相反应合成Sr2GdRuO6的反应机理.结果表明,水蒸气的作用是抑制SrRuO3的形成,而不是有利于把SrRuO3杂相转化为Sr2GdRuO6相.     

Development and validation of a reversed-phase ultra-performance liquid chromatographic method for assay of lacidipine and related substances

A simple isocratic, RP-ultra-performance LC method was developed and validated for the determination of lacidipine, three process impurities formed during synthesis, and three degradation products present in drug substance and the drug product. An efficient chromatographic separation was achieved on an Acquity BEH C18 column using pH 4.5 ammonium acetate-acetic acid buffer-methanol (70 + 30, v/v) mobile phase. The monitoring wavelength was 240 nm, and the flow rate 0.25 mL/min. Forced degradation studies using acid, alkali, peroxide, water, heat, and light were conducted, and all impurities were separated. The method was validated successfully for specificity, precision, linearity, accuracy, LOD, LOQ, and robustness, according to International Conference on Harmonization guidelines. The linearity of the calibration curve for lacidipine and each impurity was found to be very good (r2 > 0.999). This method is shown to be suitable for analysis of lacidipine to evaluate the quality of drug substance and a drug product.     

Challenges in the analytical method development and validation for an unstable active pharmaceutical ingredient

A sensitive high-performance liquid chromatography (HPLC) impurity profile method for the antibiotic ertapenem is developed and subsequently validated. The method utilizes an Inertsil phenyl column at ambient temperature, gradient elution with aqueous sodium phosphate buffer at pH 8, and acetonitrile as the mobile phase. The linearity, method precision, method ruggedness, limit of quantitation, and limit of detection of the impurity profile HPLC method are found to be satisfactory. The method is determined to be specific, as judged by resolving ertapenem from in-process impurities in crude samples and degradation products that arise from solid state thermal and light stress, acid, base, and oxidative stressed solutions. In addition, evidence is obtained by photodiode array detection studies that no degradate or impurity having a different UV spectrum coeluted with the major component in stressed or unstressed samples. The challenges during the development and validation of the method are discussed. The difficulties of analyzing an unstable active pharmaceutical ingredient (API) are addressed. Several major impurities/degradates of the API have very different UV response factors from the API. These impurities/degradates are synthesized or prepared by controlled degradation and the relative response factors are determined.     

MSn,LC‐MS‐TOF and LC‐PDA studies for identification of new degradation impurities of bupropion

Three new degradation impurities of bupropion were characterized through high performance liquid chromatography coupled to photodiode array detection and to time‐of‐flight mass spectrometry. Bupropion was subjected to the ICH prescribed stress conditions. It degraded to seven impurities (I–VII) in alkaline hydrolytic conditions which were optimally resolved on an XTerra C₁₈ column (250 × 4.6 mm, 5 µm) with a ternary mobile phase comprising ammonium formate (20 mm , pH 4.0), methanol and acetonitrile (75:10:15, v/v). The degradation impurities (III–V and VII) were characterized on the basis of mass fragmentation pattern of drug, accurate mass spectral and photodiode array data of the drug and degradation impurities. Compound V was found to be a known degradation impurity [1‐hydroxy‐1‐(3‐chlorophenyl)propan‐2‐one], whereas III, IV and VII were characterized as 2‐hydroxy‐2‐(3′‐chlorophenyl)‐3,5,5‐trimethylmorpholine, (2,4,4‐trimethyl‐1,3‐oxazolidin‐2‐yl)(3‐chlorophenyl)‐methanone and 2‐(3′‐chlorophenyl)‐3,5,5‐trimethylmorphol‐2‐ene, respectively. Compound III was a known metabolite of the drug. This additional information on the degradation impurities can help in the development of a new stability‐indicating assay method to monitor the stability of the drug product during its shelf‐life as well as in development of a drug product with increased shelf‐life. Copyright © 2013 John Wiley & Sons, Ltd.     

Role of deliquescence lowering in enhancing chemical reactivity in physical mixtures

Mixtures of deliquescent solids are susceptible to deliquescence lowering, where water vapor condensation occurs in mixtures at a lower critical relative humidity (RH(0mix)) than individual component critical relative humidities (RH(0)s). The purpose of this study was to evaluate the effect of deliquescence lowering on chemical reactivity. Sucrose, citric acid and their physical mixtures were characterized using vapor sorption analysis to determine RH(0) and RH(0mix). Acid-catalyzed sucrose hydrolysis kinetics was determined using polarimetric analysis. Physical mixtures of sucrose and citric acid crystals were prepared and stored at various relative humidities at 22 degrees C. For these physical mixtures, sucrose hydrolysis was found to occur only when the environmental RH exceeded RH(0mix). Degradation kinetics correlated with the storage RH, being fastest at higher RH. In addition, a lag period was initially observed, which was most prominent for samples stored close to RH(0mix). With exposure to RHs below RH(0mix), no sucrose degradation was detected over the experimental time period. In conclusion, mixtures of deliquescent solids showed increased water sorption at lower RHs, which caused solid dissolution and subsequently led to an increase in the chemical reactivity.     

Stress Degradation Studies on Aripiprazole and Development of a Validated Stability Indicating LC Method

The present paper describes the development of a stability indicating reversed phase column liquid chromatographic method for aripiprazole in the presence of its impurities and degradation products generated from forced decomposition studies. The drug substance was subjected to stress conditions of aqueous hydrolysis, oxidative, photolytic and thermal stress degradation. The degradation of aripiprazole was observed under acid hydrolysis and peroxide. The drug was found to be stable to other stress conditions attempted. Successful separation of the drug from the synthetic impurities and degradation products formed under stress conditions was achieved on an Inertsil phenyl column using a mixture of 0.2% trifluoroacetic acid and acetonitrile (55:45, v/v). The developed LC method was validated with respect to linearity, accuracy, precision, specificity and robustness. The assay method was found linear in the range of 25–200 μg mL^?1 with a correlation coefficient of 0.9999 and the linearity of the impurities were established from LOQ to 0.3%. Recoveries of the assay and impurities were found between 97.2 and 104.6%. The developed LC method for the related substances and assay determination of aripiprazole can be used to evaluate the quality of regular production samples. It can also be used to test the stability samples of aripiprazole. To the best of our knowledge, the validated stability indicating LC method which separates all the impurities disclosed in this investigation was not published elsewhere.     

A Validated, Specific, Stability-Indicating RP-LC Method for Analysis of Gatifloxacin in the Presence of Degradation Products and Process-Related Impurities

A validated, specific, stability-indicating reversed-phase liquid chromatographic method has been developed for quantitative analysis of gatifloxacin, its degradation products, and its process-related impurities in bulk samples and in pharmaceutical dosage forms. Forced degradation of gatifloxacin bulk sample was conducted in accordance with ICH guidelines. Acidic, basic, neutral, and oxidative hydrolysis, thermal stress, and photolytic degradation were used to assess the stability-indicating power of the method. Substantial degradation was observed during oxidative hydrolysis. No degradation was observed under the other stress conditions. The method was optimized using samples generated by forced degradation and sample solution spiked with impurities. Good resolution of the analyte peak from peaks corresponding to process-related impurities and degradation products was achieved on a C₁₈ column by use of a simple linear mobile-phase gradient prepared from mixtures of acetonitrile and an aqueous solution of sodium dihydrogen orthophosphate dihydrate and triethylamine adjusted to pH 6.5 with orthophosphoric acid. Detection was performed at 240 nm. Limits of detection and quantification were established for gatifloxacin and its process-related impurities. When the stressed test solutions were assayed by comparison with gatifloxacin working standard the mass balance was always close to 99.3%, indicating the method was stability-indicating. Validation of the method was performed in accordance with ICH requirements. The method was found to be suitable for checking the quality of bulk samples of gatifloxacin at the time of batch release and also during storage.     

Identification of degradation impurities in aripiprazole oral solution using LC–MS and development of validated stability indicating method for assay and content of two preservatives by RP-HPLC

A simple and simultaneous reverse phase high-performance liquid chromatographic method was developed for the quantification of aripiprazole (ARI) and two preservatives, namely, methyl paraben and propyl paraben in ARI oral solution. The method was developed on ACE C18 (4.6?×?250?mm, 5?µm) column using gradient elution of 0.1% v/v trifluoroacetic acid in water and acetonitrile as mobile phase components. Flow rate of 1.0?mL/min and 30°C column temperature were used for the method at quantification wavelength of 254?nm. The developed method was validated in accordance with International Conference on Harmonization guideline for various parameters. Forced degradation study was conducted in acid, base, peroxide, heat, and light stress conditions. ARI was found to degrade in oxidation, acid hydrolysis, and heat while it was stable under the remaining conditions. Specificity of the method was verified using Photo Diode Array (PDA) detector by evaluating purity of peaks from degradation samples. Major degradation impurities formed during stress study were identified using liquid chromatography–mass spectrometry method. The present method was useful for determining the content of all the three main analytes present in the oral solution without interference from degradation impurities. The method was robust under the deliberately modified conditions.     

Development and Validation of a New Analytical Method for the Determination of Related Components in Tolterodine Tartarate Using LC

A novel liquid chromatographic method has been developed, and validated for the determination of tolterodine tartarate, for its potential three impurities in drug substances and drug products. Efficient chromatographic separation was achieved on a C8 stationary phase (150 × 4.6 mm, 3.5 μm particles) with a simple mobile phase combination delivered in an isocratic mode at a flow rate of 0.8 mL min^?1 and quantitation was carried out using ultraviolet detection. Microwave assisted degradation procedure was employed for stress testing studies in addition to the conventional way of a refluxing method. The results of both studies were compared. In the developed LC method, the resolution between tolterodine and its three potential impurities was found to be greater than 2.0. Regression analysis shows an r value (correlation coefficient) greater than 0.999 for tolterodine and for its three impurities. This method was capable to detect all three impurities of tolterodine at a level below 0.0038% with respect to a test concentration of 0.5 mg mL^?1 for a 10 μL injection volume. The inter- and intra-day precisions for all three impurities and for tolterodine were found to be within 1.1% RSD at its specification level. The method has shown good, consistent recoveries for tolterodine (98.9–101.6%) and for its three impurities (94.5–103.0%). The test solution was found to be stable in the diluent for 48 h. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation, as prescribed by ICH. Degradation was found to occur in alkaline stress condition, while the drug was stable to water hydrolysis, acid hydrolysis, oxidative stress, photolytic and thermal stress. The assay of stressed samples was calculated against a qualified reference standard and the mass balance was found close to 99.5%. Microwave degradations were very fast and comparable to the conventional way of the refluxing method. Robustness studies were carried out and suggested that system suitability parameters were unaffected by small changes in critical factors. The validated method was successfully applied for the determination of tolterodine tartarate in drug substances and drug products.     

Identification of impurities in artemisinin, their behavior in high performance liquid chromatography and implications for the quality of derived anti-malarial drugs

Previous work [1] on the HPLC analysis of artemisinin tentatively identified the two impurities present above trace levels. This identification was based on LC-MS results and NMR of impurities isolated from artemisinin. In this work the impurities have been synthesized allowing verification of their identity by LC-MS. It is found that the previously suggested elution order is incorrect. A determination of relative response factors strongly impacts suggested limits on impurity levels and explains the erroneous peak assignment. The fates of the identified impurities are explored in the transformation of artemisinin to its derivative active pharmaceutical ingredients. A survey of a wide variety of artemisinin samples isolated from different geographical regions, different growing seasons, different plant backgrounds and using different extraction and purification approaches showed that artemisinin has sufficient purity for its intended use as a raw material for anti-malarial drug products.     

Stability-indicating high-performance liquid chromatographic assay of buspirone HCl

The United States Pharmacopoeia high-performance liquid chromatographic (HPLC) assay method of buspirone is not able to discriminate buspirone from its degradation products. The purpose of this work is to develop a sensitive, selective, and validated stability-indicating HPLC assay for the analysis of a buspirone hydrochloride in a bulk drug. Buspirone HCI and its potential impurities and degradation products are analyzed on an Ultrasphere C18 column heated to 40 degrees C using a gradient program that contains monobasic potassium phosphate buffer solution (pH 6.9) and acetonitrile-methanol mixture (13:17) of 35% for 5 minutes, then increased to 54% in 5.5 minutes. The samples are monitored using a photo-diode array detector and integrated at 244 and 210 nm. The stress testing of buspirone HCI shows that buspirone acid hydrochloride is the major degradation product. The developed method shows a separation of buspirone degradation product and its potential impurities in one run. The stability of buspirone HCI is studied under accelerated conditions in order to provide a rapid indication of differences that might result from a change in the manufacturing process or source of the sample. The forced degradation conditions include the effect of heat, moisture, light, acid-base hydrolysis, sonication, and oxidation. The compatibility of buspirone HCI with some pharmaceutical excipients is studied under stress conditions. The linear range of buspirone HCI is between 5 and 200 ng/microL with a limit of quantitation of 2.5 ng/microL. The intraassay percentage deviation is not more than 0.38%, and the day-to-day variation was not more than 0.80%. The selectivity, repeatability, linearity, range, accuracy, sample solution stability, ruggedness, and robustness show acceptable values.