Content determination of five constituents in Shenfukang Ⅱ capsule by HPLC / 中国药房

OBJECTIVE To develop an HPLC method for the simultaneous dete rmination of morroniside ，loganin，paeoniflorin， salvianolic acid B and icariin in Shenfukang Ⅱ capsule. METHODS The determination was performed on Agilent 5 TC-C18 column with mobile phase consisted of acetonitrile- 0.1％ phosphate acid （gradient elution ）at the flow rate of 1 mL/min. The column temperature was 30 ℃，and detection wavelength was set at 240 nm. The sample size was 10 μL. RESULTS The linear range of morroniside，loganin，paeoniflorin，salvianolic acid B and icariin were 4.80-240.00，4.84-242.00，7.00-350.00，4.72-236.00 and 5.18-259.00 μg/mL（r≥0.999 8），respectively. RSDs of precision ，stability and reproducibility tests were all lower than 3％（n＝6）. Average recoveries were 97.22％-101.36％ with the RSDs of 1.19％-2.43％（n＝6）. The contents of above 5 components in 5 batches of samples were 2.019 3-2.360 0，1.624 2-1.847 1，5.637 7-6.828 0，5.015 9-5.717 0 and 1.208 8-1.754 6 mg/g，respectively. CONCLUSIONS The method is simple ，accurate and reproducible. It can improve the quality control level of Shenfukang Ⅱ capsule.

Optimization of HPLC method using central composite design for estimation of Torsemide and Eplerenone in tablet dosage form

Abstract A simple, precise, accurate and robust high performance liquid chromatographic method has been developed for simultaneous estimation of Torsemide and Eplerenone in tablet dosage form. Design of experiment was applied for multivariate optimization of the experimental conditions of RP-HPLC method. A Central composite design was used to study the response surface methodology and to analyse in detail the effects of these independent factors on responses. Total eleven experiments along with 3 center points were performed. Two factors were selected to design the matrix, one factor is variation in ratio of Acetonitrile and the second factor is flow rate (mL/min). Optimization in chromatographic conditions was achieved by applying Central composite design. The optimized and predicted data from contour diagram comprised mobile phase (acetonitrile, water and methanol in the ratio of 50: 30: 20 v/v/v respectively), at a flow rate of 1.0 ml/min and at ambient column temperature. Using these optimum conditions baseline separation of both drugs with good resolution and run time of less than 5 minutes were achieved. The optimized assay conditions were validated as per the ICH guidelines (2005). Hence, the results showed that the Quality by design approach could successfully optimize RP-HPLC method for simultaneous estimation of Torsemide and Eplerenone.

Box–Behnken design-based HPLC optimization for quantitative analysis of chloramphenicol and hydrocortisone acetate in cream

Inserting chloramphenicol (CL) and hydrocortisone acetate (HCA) in cream preparation is intended to have activityagainst skin infection and dermatitis and such a product is available in the Indonesian market. Due to its capabilityas a separation technique, chromatography is widely used for the analysis of mixture in pharmaceutical products.The objective of this study was to develop high-performance liquid chromatography (HPLC) combined with anexperimental design for an effective analysis of CL and HCA in a cream formulation. In this study, the experimentalBox–Behnken design (BBD) was used. BBD is one of the useful experimental designs for the optimization ofchromatographic separation and analysis and for getting a better understanding of the interaction of studied factors onHPLC separation quality. Separation and HPLC analysis of CL and HCA were performed using a Shimadzu LC-20ADchromatograph, a Waters X-Bridge C-18 column (250 × 4.6 mm ID, 5 µm), and a UV-Vis detector at 261 nm. HPLCmethod was validated according to the International Conference on Harmonization by determining several analyticalperformances intended for the method’s purpose. Based on BBD, the optimal condition of HPLC was obtained usinga mobile phase of acetonitrile 47%– 53%, with a flow rate of 0.9 ml/minutes and a column temperature of 38°C. Thevalidation of HPLC resulted in the selectivity of a method with a resolution value of ≥1.5, linearity with a correlationcoefficient of >0.999, intraday and inter-day precisions with relative standard deviation values of ≤1.9%, and recoveryvalues in the range of 98%−102%. The validated method is successfully used for the analysis of CL and HCA in creamformulations. BBD could be an effective design to get the optimum reversed HPLC condition for the separation of CLand HCA in a cream formulation

Development and validation of analytical method by HPLC-DAD for determination of vasodilator active in pharmaceutical ophthalmic forms

The substance 4-Aminobenzamidine dihydrochloride (4-AD) is one of the degradation products of diminazene aceturate and has demonstrated antiglaucomatous potential. Glaucoma is the second leading cause of blindness worldwide; thus, new therapeutic alternatives must be studied, for example, the molecule 4-AD vehiculated into polymeric inserts for prolonged release. The present work aims to develop and validate an analytical method to quantify 4-AD in pharmaceutical ophthalmic forms. A HPLC was used with UV-Vis detector, at 290 ƞm and ACE® C18 column (125 × 4.6 mm, 5 µm), in which the mobile phase consists of phosphate buffer (pH 7.4) and triethylamine (30 mmol/L), under an isocratic flow of 1.0 mL/min. The retention time of 3.2 minutes was observed. The method was developed and validated in accordance with ANVISA recommendations and ICH guides. The linearity range was established between the concentrations 5 and 25 µg/mL (correlation coefficient r = 0.993). The accuracy, repeatability, and intermediate precision tests obtained a relative standard deviation less than or equal to 5%. In addition, the method was considered selective, exact. and robust, with pH being its critical factor. Therefore, the HPLC analysis method is robust and can be used to quantify 4-AD in pharmaceutical forms for ocular application.(AU)

Equilibrium solubility study to determine fexofenadine hydrochloride BCS class and challenges in establishing conditions for dissolution profiles applied to suspension

The aim of this work was to perform solubility studies for fexofenadine hydrochloride and establish dissolution conditions for this drug in oral suspension dosage form. The solubility study was executed through the shake-flask method, below 37 ºC±1 ºC, at 100 rpm stirring for 12 h in three buffer solutions: hydrochloric acid pH 2.0, acetate pH 4.5 and phosphate pH 6.8. The dissolution test was developed in vessels containing 900 mL of the same buffer, employing the paddle apparatus in speed of 25 and 50 rpm, below 37 ºC±0.5 ºC. The drug was classified as low solubility according to the Biopharmaceutics Classification System, since the dose/solubility ratio was higher than 250 mL in all media tested (326.55 mL in buffer pH 2.0; 2,456.33 mL in buffer pH 4.5 and 1,021.16 mL in buffer pH 6.8). The dissolution test showed that a release of 85% in 30 min could be established. The rotation speed of 25 rpm, media volume of 900 mL and insertion of the samples through weighted syringes are adequate. The buffered media pH 2.0 could be chosen as dissolution media.

PEG-PCL Nanocapsules Containing Curcumin: Validation of HPLC Method for Analyzing Drug-loading Efficiency, Stability Testing and Cytotoxicity on NIH-3T3 Cell Line

Abstract Curcumin (CUR) shows potential use for treating cancer. However, CUR has low solubility and reduced bioavailability, which limit its clinical effect. Therefore, the development of nanocarriers can overcome these problems and can ensure the desired pharmacological effect. In addition, it is mandatory to prove the quality, the efficacy, and the safety for a novel nanomedicine to be approved. In that sense, this paper aimed (a) to prepare CUR-loaded polyethylene glycol-poly(ε-caprolactone) nanocapsules; (b) to validate an analytical method by high performance liquid chromatography (HPLC) for quantifying CUR in these nanoformulations; (c) to evaluate the physicochemical stability of these formulations; and to investigate their cytotoxicity on NIH-3T3 mouse fibroblast cells. The HPLC method was specific to CUR in the loaded nanocapsules, linear (r = 0.9994) in a range of 10.0 to 90.0 µg.mL-1 with limits of detection and quantification of 0.160 and 0.480 µg.mL-1, respectively. Precision was demonstrated by a relative standard deviation lower than 5%. Suitable accuracy (102.37 ± 0.92%) was obtained. Values of pH, particle size, polydispersity index, and zeta potential presented no statistical difference (p > 0.05) for CUR-loaded nanoparticles. No cytotoxicity was observed against NIH-3T3 mouse embryo fibroblast cell line using both the tetrazolium salt and sulforhodamine B assays. In conclusion, a simple and inexpensive HPLC method was validated for the CUR quantification in the suspensions of nanocapsules. The obtained polymeric nanocapsules containing CUR showed suitable results for all the performed assays and can be further investigated as a feasible novel approach for cancer treatment.

RP-HPLC method for determination of norethindrone in dissolution media and application to study release from a controlled release nanoparticulate liquid medicated formulation

Several methods are available for the determination of norethindrone. These methods are either complicated or needvalidation. The objective of this work was to develop and validate a simple reversed phase-high performance liquidchromatographic method for the determination of norethindrone in dissolution media. A Thermo Scientific C18column (250 mm × 4.6 mm ID, 5 µm pore size) was used. A mobile phase consisting of deionized water: acetonitrile(50:50, v/v) and 5 ml/l acetic acid was used. The flow rate was 1.3 ml/minute and the wavelength of the detectionwas 245 nm. Validation of linearity, accuracy and precision, limit of detection, limit of quantification, specificity, andstability (degradation) was carried out according to the International Conference on Harmonization guidelines. Thedeveloped and validated method was used to study norethindrone release from a nanoparticulate liquid medicatedformulation (LMF). The results indicated that the method was simple, accurate and precise, and met the acceptancecriteria. The drug exhibited higher stability in basic media when compared to acidic media. Drug release from a LMF(nanoemulsion) followed zero order kinetics. In conclusion, a simple method was developed, validated, and usedsuccessfully in evaluating in vitro drug release from a sustained release/controlled release nanoparticulate LMF.

Qualitative and Quantitative Study of Tibetan Medicine Thlaspi semen / 中国药房

OBJECTIVE： To establish the qualitative and quantitative control method of Tibetan medicine Thlaspi semen. METHODS： TLC and HPLC method were used to identify and determine flavonoids isovitexin， swertisin and glucosinolates sinigrin from 15 batches of T. semen. The stationary phases identified by TLC of flavonoids and glucosinolates were polyamide film and high performance silica gel GF254. The developing agents were trichloromethane-methanol-glacial acetic acid （11 ∶ 1 ∶ 1，V/V/V） and ethyl acetate-methanol- triethylamine （4 ∶ 5 ∶ 0.5，V/V/V）. In chromatogram condition of content determination of isovitexin and swertisin， the separation was performed on CAPCELL PAK MGⅡ C18 column with mobile phase composed of acetonitrile-0.4％ glacial acetic acid solution （gradient elution） at the flow rate of 1.0 mL/min. The detection wavelength was set at 336 nm. In chromatogram condition of content determination of sinigrin， the separation was performed on CAPCELL PAK MGⅡ C18 column with mobile phase composed of acetonitrile-0.02 mol/L tetrabutylammonium hydrogen sulfate （15 ∶ 85，V/V，pH 6） at the flow rate of 1.0 mL/min. The detection wavelength was set at 227 nm. RESULTS： In TLC identification chromatogram， spots corresponding to isovitexin， swertisin and sinigrin control were detected in test samples. The linear ranges of isovitexin， swertisin and sinigrin were 1.26-79.00， 1.21-75.38， 12.80-640.00 μg/mL， respectively （all r≥0.999 5）. The limits of detection （LODs） were 0.09， 0.12， 0.15 μg/mL， and limits of quantitation （LOQs） were 0.39， 0.43， 0.54 μg/mL， respectively. RSDs of precision， stability （24 h） and reproducibility tests were all lower than 2.0％（n＝6）. The recoveries were 99.1％， 97.0％ and 98.1％， and RSDs were 1.9％， 1.8％， 1.8％（n＝6），respectively. The contents of isovitexin， swertisin and sinigrin in 15 batches of T. semen were 0.013-0.090， 0.020-0.130 and 18.92-40.75 mg/g， respectively. CONCLUSIONS： Established quality control method is simple， reproducible and stable， and can be used for the quality control of Tibetan medicine T. semen.

Identification of all herb medicines in Fuhuang Tablet / 中草药

Objective To establish the identification method of Typha angustifolia (stir-bake to black), Sophora japonica, Sanguisorba officinalis (stir-bake to black), and Rheum palmatum in Fuhuang tablets. Methods HPLC method were studied to identify typhaneoside and isorhamnetin-3-O-neoheptanoside in T. angustifolia, and sophoricoside in S. japonica. HPLC conditions were as follows: Agilent TC-C18 (2) column (250 mm × 4.6 mm, 5 μm) with a gradient elution at a temperature of 30 ℃; Phosphate buffer and acetonitrile were used as the mobile phase with a flow rate of 1.0 mL/min; The detection wavelength was 254 nm. The acid hydrolysis-HPLC method was explored to identify S. officinalis (stir-bake to black). TLC identification method was performed to identify R. palmatum. Results HPLC method can identify typhaneoside, isorhamnetin-3-O-neoheptanoside, and sophoricoside synchronously. Acid hydrolysis method can identify S. officinalis (stir-bake to black) by HPLC and TLC can identify R. palmatum. Conclusion The three methods are simple and accurate with high sensitivity and good specificity, which can be used to identify all herbal medicines in Fuhuang tablets.

Forced degradation of gliquidone and development of validated stability-indicating HPLC and TLC methods

Forced degradation studies of gliquidone were conducted under different stress conditions. Three degradates were observed upon using HPLC and TLC and elucidated by LC-MS and IR. HPLC method was performed on C18 column using methanol-water (85:15 v/v) pH 3.5 as a mobile phase with isocratic mode at 1 mL.min-1 and detection at 225 nm. HPLC analysis was applied in range of 0.5-20 µg.mL-1 (r =1) with limit of detection (LOD) 0.177 µg.mL-1. TLC method was based on the separation of gliquidone from degradation products on silica gel TLC F254 plates using chloroform-cyclohexane-glacial acetic acid (6:3:1v/v) as a developing system with relative retardation 1.15±0.01. Densitometric measurements were achieved in range of 2 -20 µg /band at 254 nm (r = 0.9999) with LOD of 0.26 µg /band. Least squares regression analysis was applied to provide mathematical estimates of the degree of linearity. The analysis revealed a linear calibration for HPLC where a binomial relationship for TLC. Stability testing and methods validation have been evaluated according to International Conference on Harmonization guidelines. Moreover, the proposed methods were applied for the analysis of tablets and the results obtained were statistically compared with those of pharmacopeial method revealing no significant difference about accuracy and precision.

Determination of asperosaponin VI, psoralen, and angelicin in Xianling Gubao Capsule by HPLC / 中草药

Objective: To determine asperosaponin VI, psoralen, and angelicin in Xianling Gubao Capsules (XGC) via multi- wavelength HPLC method. Methods: Separation was carried out on Welch Ultimate® XB-C18 column. The mobile phase was acetonitrile-water system and a linear gradient elution was used. The column temperature was 30℃. The detection wavelength for asperosaponin VI was set at 212 nm, those for psoralen and angelicin were set at 246 nm. Results: Three components reached baseline separation, the linearity was good when sample volumes were in the ranges of 144.1-5 764.0 for asperosaponin VI (r = 0.999 6), 5.4-215.2 (r = 0.998 0) for psoralen, and 6.6-265.6 ng (r = 0.998 5) for angelicin. The average recoveries of asperosaponin VI, psoralen, and psoralen were 98.11%, 97.86%, and 98.22%, respectively. The RSDs of recoveries were all less than 2.0%. Conclusion: The method is simple and accurate and has good separation, with high sensitivity and good efficiency for the determination of more-index components in XGC.

Development of a Validated HPLC Method for the Estimation of Metformin HCl and Propranolol HCl.

The present investigation targets to develop a simple, specific, sensitive and accurate reverse phase high performance liquid chromatographic (RP-HPLC) method in human plasma for the estimation of metformin HCl and propranolol HCl from bulk drug and also from the marketed products. Human plasma samples were subjected to correct procedure for protein precipitation by methanol and protein free plasma samples were directly injected into HPLC C18 column. Chromatographic determination was performed on a reversed phase C18 column (3.9 mm X 300 mm, particle size 5 μm) using a mixture of acetonitrile and 0.1M pH 4.5 potassium dihydrogenortho phosphate buffer (mL) (40:60) at a flow rate of 0.8 mL/min and maintained at a pressure of 140 to 150 Kg/cm2. The retention time for metformin HCl and propranolol HCl was found to be 9.084 min and 6.132 min respectively at 232 nm without any interference of endogenous compounds in the plasma. The method was linear in the range between 50-2000 ng/mL. The peak areas were reproducible as indicated by low coefficient of variation. It was found that the excipients in the tablet dosage form do not interfere in the quantification of active drug by proposed method.

Simultaneous estimation of Cefpodoxime proxetil and Ofloxacin In tablet dosage form using RP-HPLC.

A simple, rapid and precise reverse phase liquid chromatographic (RP-HPLC) method was developed and subsequently validated for simultaneous estimation of Cefpodoxime proxetil and Ofloxacin in combined fixed dose oral formulation. The analysis was carried out using X-terra C8 (4.6 x 250mm, 5μm, Make: ACE), prepacked column. The separation was carried out using a mobile phase containing a 0.25%v/v triethyl amine buffer of pH 3.5 and acetonitrile (30:70 v/v), was pumped at a flow rate of 1.2 ml/min with UV-detector and PDA detection at 227 nm. Both the drugs were well resolved on the stationary phase and the retention times were around 2.747 minute for Cefpodoxime proxetil and 2.076 minute for Ofloxacin. The method was validated and shown to be linear for Cefpodoxime proxetil and Ofloxacin. The correlation coefficients for Cefpodoxime proxetil and Ofloxacin are 0.998 and 0.999 respectively. The relative standard deviations for five replicate measurements in two sets of each drug in the tablets is always less than 2% and mean % error of active recovery not more than ±1.5%. The method was validated for precision and accuracy. The developed method could be applied for routine analysis of Cefpodoxime proxetil and Ofloxacin in tablet dosage form without any interference of excipients.

Simultaneous determination for contents of naringin, hesperidin, and neohesperidin in flower of Citrus changshan-huyou by RP-HPLC / 中草药

Objective: To establish a method for the simultaneous determination for the contents of naringin, hesperidin, and neohesperidin in the flower of Citrus changshanhuyou by RP-HPLC. Methods: The HPLC method was adopted with Agilent Zorbax SB-C18 (250 mm × 4.6 mm, 5 μm) column; The mobile phase was acetonitrile-0.2% aqueous phosphoric acid (15:85) with the flow rate of 1.0 mL/min. The detection wavelength was 284 nm and column temperature was 40°C; The peak areas were quantified by external standard method. Results: According to the method, naringin linear was within 28.45-284.5 ng, the regression equation was Y = 1725.2X + 6.383 3 (r = 0.9998), and the average recovery rate was 98.83%. Hesperidin linear was within 18.09-180.93 ng, Y=1764.6 X+0.4167 (r = 0.9998) with the average recovery rate of 99.05%. Neohesperidin linear was within 85.86-858.55 ng, Y = 1914.7X + 15.892 (r = 0.9996), and the average recovery rate was 98.83%. According to the established method, the contents of sample, naringin, hesperidin, and neohesperidin were respectively determined. Conclusion: The method is simple, rapid, accurate, and reliable, which provides the reference for the quality control for the flower of C. changshanhuyou, and is suitable for the content determination.

Variation analysis on triterpene compounds in hawthorn from different regions / 中草药

Objective: To establish an HPLC method for the content determination of ursolic acid and oleanolic acid in hawthorn (Crataegi Fructus) from different regions, whose differences were compared. Methods: Waters Symmetry C18 column (4.6 mm× 250 mm, 5 μm) was used with the mobile phase of acetonitrile-methanol-0.5% ammonium acetate (69:12:19) at a flow rate of 1 mL/min. The detection wavelength was set at 210 nm and the column temperature was 30°C. To determine the content of hawthorn from 10 different regions, variance analysis and cluster analysis were carried out for the results. Results: The linear ranges of ursolic acid and oleanolic acid were 0.078-0.780 mg/mL(r = 0.9998, n = 6) and 0.0169-0.169 mg/mL (r = 0.9996, n = 6), respectively. The average recoveries of the two components were 102.6% and 100.2%, in accordance with the determination requirement in Chinese Pharmacopoeia 2010. Conclusion: This method is simple, quick, accurate, and has better reproducibility for the determination of triterpene compounds in hawthorn. And hawthorn from Chengde and Jiangsu provinces is better. It could be used as the origin of hawthorn in the prescription of Xin mai Capsule.

Selective separation, detection of zotepine and mass spectral characterization of degradants by LC-MS/MS/QTOF / 药物分析学报

A simple, precise, accurate stability-indicating gradient reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed for the quantitative determination of zotepine (ZTP) in bulk and pharmaceutical dosage forms in the presence of its degradation products (DPs). The method was developed using Phenomenex C18 column (250 mm ~ 4.6 mm i.d., 5 mm) with a mobile phase containing a gradient mixture of solvents, A (0.05%trifluoroacetic acid (TFA), pH ? 3.0) and B (acetonitrile). The eluted compounds were monitored at 254 nm;the run time was within 20.0 min, in which ZTP and its DPs were well separated, with a resolution of 41.5. The stress testing of ZTP was carried out under acidic, alkaline, neutral hydrolysis, oxidative, photolytic and thermal stress conditions. ZTP was found to degrade significantly in acidic, photolytic, thermal and oxidative stress conditions and remain stable in basic and neutral conditions. The developed method was validated with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness as per ICH guidelines. This method was also suitable for the assay determination of ZTP in pharmaceutical dosage forms. The DPs were characterized by LC-MS/MS and their fragmentation pathways were proposed.

Composition Analysis of Ginsenoside from Different Fractions of Ginseng / 世界科学技术-中医药现代化

This study was aimed to measure the content of ginsenoside in ginseng extract by UV/HPLC. Through the approximate translation comparison of two different testing results with UV and HPLC in current market, and several typical HPLC peaks ratio analysis on contents of different ginsenoside extracted from the root, stem and leaves of ginseng, in order to establish identification method of ginsenoside from different sources. The results showed that the ratio for Re:Rb1:Rc:Rd in ginseng root extract was approximately 1:2.20:0.94:0.97. And the ratio for Re:Rb1:Rc:Rd in ginseng leave extract was approximately 1:(0.05~0.07):(0.10~0.16):(0.32~0.37). Compared with the mixture of ginseng root and ginseng leave extract, the theoretical value of Re:Rb1:Rc:Rd should between those two ratios. It was concluded that this method was simple, stable and reliable, which can be used as the identification method of ginsenoside from ginseng root, stem and leaves.

Study on Spray Drying Technology of Instant Asini Corii Colla / 世界科学技术-中医药现代化

This article was aimed to research the spray drying technology of instant Asini Corii Colla. HPLC was used. Contents of four kinds of amino acid and collection rate of powder were used as the indexes. The single factor experiment and orthogonal test were combined in the optimization of process conditions. The results showed that the best technology of spray drying technology was medicine liquid density of 1.10 (determined under the temperature of 60℃), inlet air temperature at 165℃, the pressed air speed was 45 L·h-1, the fluid speed was 15%. It was conclud-ed that the technology was reasonable and reliable, which can provide certain reference in the industrial production.

RP-HPLC analysis of manool-rich Salvia officinalis extract and its antimicrobial activity against bacteria associated with dental caries

In this paper we screened the dichloromethane extract from the aerial parts of Salvia officinalis L., Lamiaceae, against a representative panel of microorganisms that cause caries, conducted a bioassay-guided fractionation to establish themselves the most active metabolite (manool) and determined the Salvia officinalis fraction with the manool highest concentration to be used to activate an ingredient in oral care products such as toothpastes and mouthwashes. Both manool and S. officinalis extract showed very promising minimal inhibitory concentration values (between 6.24 and 31.36 µg.ml-1) and time kill curves against the primary causative agents of dental caries (Streptococcus mutans) revealed that, at twice its minimal bactericidal concentration (12.48 µg.ml-1), manool required 6 h to completely kill the bacteria. Salvia officinalis extract at twice its minimal bactericidal concentration (31.36 µg.ml-1 ) needed 12 h. The results achieved with Salvia officinalis extract motivated us to develop and validate an analytical RP-HPLC method to detect and determine manool in this extract. The validation parameters were satisfactorily met and evaluated allows us to consider the developed method suitable for use in different labs. In conclusion, our results evidenced that the manool-rich S. officinalis extract can be considered an analytically validated alternative to develop novel and effective antimicrobial agents against the main bacteria responsible for dental caries.

Simultaneous estimation of drotaverine hydrochloride and paracetamol in bulk and tablet dosage form by RP-HPLC method.

A simple, rapid, reproducible, accurate and precise Reverse Phase HPLC method was developed for the quantitative simultaneous estimation of Drotaverine hydrochloride and Paracetamol in combined tablet dosage form. Drotaverine hydrochloride is an analog of papaver and is used mainly as an antispasmodic, smooth muscle relaxant. Paracetamol has analgesic and antipyretic activity. The chromatographic separation of both drugs was achieved with 250 x 4.6 mm, i.d 5 μm C-18 column using Methanol: water pH adjusted to 4.0 with O- Phosphoric acid. (60:40 v/v) at the flow rate of 1ml/min. The measurements were made at 243.0 nm using UV detector. The linearity range was found to be 5-80 μg/ml for Drotaverine hydrochloride and 5-70 μg/ml for Paracetamol. The coefficient of correlation for Drotaverine hydrochloride and Paracetamol was found to be 0.9994 and 0.9990 respectively. The retention time for Drotaverine hydrochloride and Paracetamol were 4.562 min and 8.146 min, respectively. The tailing factor for Drotaverine hydrochloride and Paracetamol was found to be 1.12 and 1.18 respectively. The percent recoveries obtained for Drotaverine hydrochloride and Paracetamol were found to be 99.85 and 99.92 respectively. The relative standard deviation for intraday and interday precision in tablet was always less than 2%. The method was validated for linearity, range, precision, accuracy, specificity, selectivity, intermediate precision, ruggedness, robustness, stability and suitability.