Development and Validation of Chiral Separation of Some Enantiomeric Drugs by HPLC and LC-MS

This thesis deals with the studies carried out by the writer in the laboratory for the past four years on the development and validation of chiral separation of some enantiomeric drugs by HPLC and LC-MS methods. Thesis begins with a brief introduction of the reasons for analysing enantiomeric drugs and introduction to the analytical methods used like HPLC and LC-MS. The methods used for the quantitative analysis of enantiomers and the introduction to the chiral separation are given. Thesis deals with the aim and objective of the present work, the reasons for analysing the enantiomers and need for newer analytical methods for the estimation of enantiomers in pharmaceutical formulation are briefly discussed. Thesis deals with the reviews of literature on the analytical methods available for the estimation of the drug candidates in pharmaceutical formulations are explained. Thesis deals with the materials and instruments used in the experimental procedures adopted. It describes in detail the procedure adopted for the optimisation of the chromatographic conditions for the chiral separation of drugs by HPLC and LC-MS methods and for the estimation of enantiomers in the selected drug candidates are presented and discussed. Forced degradation studies on the selected racemic drugs using acid, alkaline, neutral, oxidative and photolytic degradations and quantification of enantiomers by HPLC in different stress conditions are presented and discussed. The results obtained are presented and discussed. HPLC and LC-MS chromatograms of the standard and sample solutions, calibration curves for the selected analytes are also presented. The results of the experiments carried out to check the accuracy, reproducibility of the methods carried out are presented and discussed in detail. System suitability studies and forced degradation studies carried out for various methods developed are also presented and discussed. The following are some of the salient features and conclusions made for the present study. • Four racemic drugs namely Rosiglitazone, Pioglitazone, Zaltoprofen and Valganciclovir Hydrochloride for which there were no HPLC and LC-MS methods reported for the estimation of enantiomers in pharmaceutical formulations and their stability in different stress conditions were selected for the present study after thorough literature survey. • The chromatographic conditions like detection wavelength/mass range, nature and composition of mobile phase, nature of stationary phase, peak modifiers, flow rate etc were optimised for the best possible separation and quantification of the analytes. Forced degradation studies on the selected racemic drugs using acid, alkaline, neutral, oxidative and photolytic degradations were performed. • The developed HPLC and LC-MS methods were validated for their transferability to other laboratories, in terms of specificity, selectivity, accuracy, precision, linearity and range, detection and quantification limits, ruggedness, robustness and system suitability. The validation studies carried out revealed that the developed methods satisfy the ideal characteristics of the analytical methods. • The direct and indirect chiral HPLC and LC-MS methods developed in the present study for the estimation were found to be simple, rapid, accurate, precise, specific, linear and rugged. They are thus suitable for the estimation of enantiomers in raw materials and formulations. The newly developed analytical methods can be used in the following fields: • Research institutions, • Academic institutes, • Quality control department in industries, • Approved testing laboratories, • Biopharmaceutics and bioequivalence studies and • Clinical and pharmacokinetic studies after suitable modification

STABILITY INDICATING CHIRAL HPLC METHOD FOR THE ESTIMATION OF PIOGLITAZONE ENANTIOMERS IN PHARMACEUTICAL FORMULATION

Objective: A stability indicating chiral high performance liquid chromatographic (HPLC) method was developed and validated for the separated (S)and (R) pioglitazone in raw material and its determination in the presence of degradation products formed during forced degradation studies.Methods: In the present study, an isocratic normal phase-HPLC method was developed with stationary phase as ACI Cellu 1 (150 mm × 4.6 mm i.d.,5  μ)  column  and  n-hexane:  N-propyl  alcohol  (80:20,  V/V)  as  mobile  phase.  The  entire  study  was  performed  using  1.0  ml/minute  as  flow  rate  and the detection wavelength at  233 nm. The pioglitazone (R and S) was exposed to various stress condition such as hydrolytic (acid and base), neutral, oxidative, and photolytic. The stressed samples were analyzed by the proposed method.Result:  The  described  method  was  linear  over  the  range  of  5-15 µg/ml  for  R-pioglitazone  and  4-14 µg/ml  for  S-pioglitazone.  The  limit  of  detection and limit of quantification of S-pioglitazone and R-pioglitazone were found to be 1.4 μg/ml and 4.26 μg/ml, respectively. The recovery study of S and R-Pioglitazone from tablets formulation ranged from 97.14% to 100.04%, respectively.Conclusion: The developed method can be applied in the quality control of drug products.Keywords: Stability-indicating method, Validation, Chiral, Pioglitazone

A NEW VALIDATED CHIRAL RP-HPLC METHOD FOR THE DETERMINATION OF STABILITY OF MEBEVERINE ENANTIOMERS IN THE PRESENCE OF ITS DEGRADATION PRODUCTS

Objective: An enantioselective reverse phase high performance liquid chromatographic method was developed and validated for the analysis of mebeverine enantiomers. This method was used to investigate the stability and degradation behaviour of mebeverine under different stress conditions recommended by International Conference on Harmonization (ICH).Methods: An Isocratic chiral RP-HPLC method for the resolution of mebeverine and its degradation products was successfully achieved on a Phenomenex® lux cellulose 1 column, using UV detector at wavelength of 219 nm, with a mobile phase consisting of 0.1% diethyl amine in methanol, 20 mM ammonium bicarbonate (pH: 4.6) adjusted with trifluroacetic acid, 0.1% diethyl amine in isopropyl alcohol (55: 15: 30 v/v/v), and a flow rate of 1.2 ml/min. The drug was subjected to alkaline, acidic, neutral, oxidative, and photolytic conditions in order to mimic stress conditions. The stressed samples were also analysed by this method.Results: The method developed provided the linear correlation (R2 =0.999) for the drug between a range of 56–84 µg/ml for (-) mebeverine and 52–78 µg/ml (+) mebeverine respectively. The limit of detection and limit of quantification of (-) mebeverine was found to be 0.30 µg/ml, 0.90 µg/ml and (+) mebeverine was found to be 0.32 µg/ml, 0.97 µg/ml respectively.Conclusion: The method developed was found to provides good sensitivity and excellent precision and reproducibility and can be applied in the quality control of drug products.Â

Microwave Irradated Synthesis, Characterization and Evaluation for their Antibacterial and Larvicidal Activities of some Novel Chalcone and Isoxazole Substituted 9-Anilino Acridines

Introduction: Chalcone, isoxazole and acridines have diverse biological activities. A series of novel chalcone and isoxazole substituted 9-anilinoacridines were synthesized for their antibacterial, larvicidal, activities.Methods: A series of novel chalcone and isoxazole substituted 9-anilinoacridines (3a-h and 4a-h) were synthesized from 9-chloroacridine by microwave irradiation method. The antibacterial evaluation was performed by cup-plate method and screened for their larvicidal activity by larval bioassay method. Result: The compounds 3d, 3e, 3f, 3h, 4d, 4f have significant antibacterial activity against Gram +ve bacteria like Staphylococcus aureus, Bacillus megaterium, and Gram –ve Escherichia coli, Klebsiella pneumoniae at 25μg/ml. Compounds 3c, 3f, 4a, 4f have significant larvicidal activity against culex and anopheles species at LC50value of 17-36ppm.Conclusion: Many of the compounds have significant antibacterial and larvicidal activities, which are used for further refinement.</p

Extranodal non-Hodgkin's lymphoma presenting as gingival mass

Non-Hodgkin's lymphoma (NHL) commonly presents as non-tender, enlarged lymph nodes, accompanied by diffuse symptoms of fatigue and low-grade intermittent fever and it is derived predominantly from the cells of the B lymphocyte series. NHL cases occur extra-nodally and in 3% of these cases the initial presentation may be in the oral cavity. Though extra-nodal NHL of the oral cavity is a rare finding, patients with oral lesions of NHL commonly present at the dental clinic in the first instance. A careful clinical evaluation supported by histopathological and other laboratory investigations will help in identifying the disease at an early stage, resulting in better prognosis. Any delay in diagnosis has important implications on the morbidity and mortality of the condition. Due to the rarity of intraoral NHL, we present one such a case with a complaint of tumor-like mass on the gingiva of lower molar region. The lesion was clinically thought as pyogenic granuloma and later diagnosed as extra nodal NHL of the oral cavity

Trabecular Variant of Juvenile Aggressive Ossifying Fibroma of Anterior Mandible

Juvenile ossifying fibroma (JOF) is an expansile intra-osseous lesion of the jaw that emulate odontogenic lesions frequently seen in patients under 15 years of age. They are histologically characterized by the presence of fibrous stromal cells along with mineralized tissues. Clinically, these are characterized by early age of onset, histological patterns, high rate of recurrence and the aggressive local behavior. The differential diagnosis of JOF with other fibro-osseous lesions of the jaw should be made along with an essential microscopic examination and be largely based on the character of the calcified products of the tumor. The purpose of this article is to present a rare clinical case of the trabecular type of JOF and to describe its clinical, radiological and histological characteristics. The clinician should be aware of this type of lesion in order to be able to distinguish this it from other fibrous lesions if encountered in routine practice and for appropriate treatment to be carried out

Green synthesis of some novel chalcone and isoxazole substituted 9-anilinoacridine derivatives and evaluation of their antimicrobial and larvicidal activities

583-590Synthesis of some novel 9-anilinoacridine derivatives 3a-j and 4a-j from 9-cloroacridine under MW irradiation have been reported. The structures of the synthesized compounds have been confirmed by physical and analytical data. The synthesized compounds have been screened for their in vitro anti-microbial activities against Staphylococcus aureus, Bacillus megaterium, Escherichia coli, Klebsiella pneumoniae, Candida albicans and Aspergillus niger. Their larvicidal activity against Culex quinquefasciatus and Anopheles stephensi have also been screened by larval bioassay method. Many of the compounds have significant antimicrobial and larvicidal activities

Microwave assisted synthesis of some novel pyrazole substituted benzimidazoles and evaluation of their biological activities

1794-1799<span style="font-size:12.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-ansi-language:="" en-gb;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-GB">A series of novel and significant compounds containing pyrazole substituted benzimidazoles 4a-h and<b style="mso-bidi-font-weight: normal"> 5a-h have been synthesized from <i style="mso-bidi-font-style: normal">o-phenylenediamine under microwave irradiation. The structures of the newly synthesized compounds have been confirmed on the basis of elemental analysis and spectral data. Some of the synthesized compounds 4b, 4h, 5d, 5f exhibit significant antibacterial activity. The compounds 5b, 5f exhibit good antifungal activity. Compounds <b style="mso-bidi-font-weight: normal">5a and 5b have shown good anticancer activity and the compound 4a exhibits significant anti tubercular activity.</span