Pharmaceutical Analysis

The provision of high-quality education and training that is responsive, relevant, accessible and evidence based is critical if the vision for quality mental health services presented in recent policy initiatives in Ireland is to be fulfilled. This paper reports the findings related to pedagogical approaches and quality assurance mechanisms utilized within mental health education. The study involved canvassing all Higher Education Institutions in Ireland. A total of 227 courses in 31 educational institutes were identified and 149 questionnaires were returned from 129 Course Coordinators. Various quality processes were identified in existing programs; however, formal feedback from service providers, service users and carers was seldom reported.

Upper extremity tendinopathies are associated with performance of forceful repetitive tasks. We used our rat model of repetitive strain injury to study changes induced in forelimb flexor digitorum tendons. Rats were trained to perform a high repetition high force (HRHF) handle-pulling task (12 reaches/min at 60 ± 5 % maximum pulling force (MPF)), or a low repetition negligible force (LRNF) reaching and food retrieval task (3 reaches/min at 5 ± 5% MPF), for 2 hrs/day in 30 min sessions, 3 days/wk for 3-12 weeks. Forelimb grip strength was tested. Flexor digitorum tendons were examined at mid tendon at the level of the carpal tunnel for interleukin (IL)-1β; neutrophil and macrophage influx; Substance P, connective tissue growth factor (CTGF) and periostin like factor (PLF) immunoexpression; and histopathological changes. In HRHF rats, grip strength progressively decreased, while IL-1β levels progressively increased in the flexor digitorum peritendon (para-and epitendon combined) and endotendon with task performance. Macrophage invasion was evident in week 6 and 12 HRHF peritendon but not endotendon. Also in HRHF rats, Substance P immunoexpression increased in week 12 peritendon as did CTGF-and PLFimmunopositive fibroblasts, the increased fibroblasts contributing greatly to peritendon thickening. Endotendon collagen disorganization was evident in week 12 HRHF tendons. LRNF tendons did not differ from controls, even at 12 weeks. Thus, we observed exposure dependent changes in flexor digitorum tendons within the carpal tunnel, including increased inflammation, nociceptor-related neuropeptide immunoexpression, and fibrotic histopathology, changes associated with grip strength declines.

Glimepiride is an oral anti-diabetic drug, which is mostly used in the treatment of Type 2 diabetes mellitus. It acts by stimulating insulin secretions from the beta cells of pancreas and is also known to enhance the peripheral insulin sensitivity thereby decreasing insulin resistance. This article examines published analytical methods that are reported so far for the determination of glimepiride in pharmaceutical formulations and biological samples. They include various techniques like spectrophotometry, electrochemical methods, capillary electrophoresis, high-performance liquid chromatography, micellarelectro kinetic capillary chromatography(MECC) with diode-array detection (DAD), liquid chromatography-electrospray ionization-tandem mass spectroscopy (LC-ESI-MS), liquid chromatography-mass spectroscopy (LC-MS) and thin layer chromatography (TLC).

Three new simple and sensitive spectrophotometric methods in UV/Vis region have been developed for the determination of raloxifene hydrochloride in bulk drug and in tablet formulations. Raloxifene hydrochloride exhibited maximum absorbance at 289 nm in methanol (method A) with apparent molar absorptivity of 3.67× × × × ×10 4 l/mol.cm and maximum absorbance at 303 nm in 0.1 M sodium hydroxide with apparent molar absorptivity of 3.60× × × × ×10 4 l/mol.cm (method B). Third method is based on the formation of red coloured chromogen with ferric nitrate and 1,10-phenanthroline, which showed maximum absorbance at 511 nm with apparent molar absorptivity of 1.06× × × × ×10 5 l/mol.cm. Beer's law was obeyed in the concentration range of 5-25 µg/ml for method A and B and in the range of 2-10 µg/ml for method C. Results of all methods were validated statistically and by recovery studies.

A simple, efficient, and reproducible method for the determination of raloxifene hydrochloride in tablets has been developed using reverse phase high performance liquid chromatographic method. The elution was done using a mobile phase consisting of methanol and water (50:50 v/v) on Water's Symmetry C 18 4.6× × × × ×150 mm analytical column with flow rate of 1 ml/min with detection at 230 nm. An external standard calibration method was employed for quantitation. The elution time was 4.1 min. The linearity range was 10-60 µg/ml for raloxifene hydrochloride.

Two chemometric methods were developed for the simultaneous determination of telmisartan and hydrochlorothiazide. The chemometric methods applied were principal component regression (PCR) and partial least square (PLS-1). These approaches were successfully applied to quantify the two drugs in the mixture using the information included in the UV absorption spectra of appropriate solutions in the range of 200-350 nm with the intervals Dl 5 1 nm. The calibration of PCR and PLS-1 models was evaluated by internal validation (prediction of compounds in its own designed training set of calibration) and by external validation over laboratory prepared mixtures and pharmaceutical preparations. The PCR and PLS-1 methods require neither any separation step, nor any prior graphical treatment of the overlapping spectra of the two drugs in a mixture. The results of PCR and PLS-1 methods were compared with each other and a good agreement was found.

A Simple high-performance thin layer chromatography (HPTLC) method for separation and quantitative analysis of losartan potassium, amlodipine, and hydrochlorothiazide in bulk and in pharmaceutical formulations has been established and validated. After extraction with methanol, sample and standard solutions were applied to silica gel plates and developed with chloroform : methanol : acetone : formic acid 7.5 : 1.3 : 0.5 : 0.03 (v/v/v/v) as mobile phase. Zones were scanned densitometrically at 254 nm. The R f values of amlodipine besylate, hydrochlorothiazide, and losartan potassium were 0.35, 0.57, and 0.74, respectively. Calibration plots were linear in the ranges 500-3000 ng per spot for losartan potassium, amlodipine and hydrochlorothiazide, the correlation coefficients, r, were 0.998, 0.998, and 0.999, respectively. The suitability of this method for quantitative determination of these compounds was by validation in accordance with the requirements of pharmaceutical regulatory standards. The method can be used for routine analysis of these drugs in bulk and in formulation.

Simultaneous spectrophotometric method described for the determination of Ramipril, Hydrochlorothiazide and Telmisartan in tablets using absorbance correction -H-Point Standard addition method (HPSAM). A simple and novel method absorbance correction -HPSAM is reported for simultaneous estimation of three drugs using UV-visible spectrophotometry without any prior separation of samples. The linear range was 0.8 -3 µg/mL for Ramipril, Hydrocholrothiazide and Telmisartan. The relative standard deviation (RSD) for the simultaneous determination of 2 µg/mL of Ramipril, hydrochlorothiazide and Telmisartan by applying HPSAM was 0.373, 1.176 and 1.296 respectively. The reported methods HPSAM can be claimed as green analytical chemistry as it does not involve the use of organic solvents and hence can be utilized for the routine analysis of these drugs from tablets.

The present work describes a simple reverse phase HPLC method for the determination of Paracetamol and Lornoxicam from tablet formulations. The determination was carried out on a Phenomenex ODS, C-18 (150 × 4.6 mm, 5 micron) column using mobile phase of acetonitrile: methanol: 0.1M sodium dihydrogen phosphate (pH 3.6) in the ratio of 80:10:10 v/v/v. The flow rate and the run time were 1 ml/min and 10 min, respectively. The eluent was monitored at 260 nm. The method was reproducible, with good resolution between paracetamol and lornoxicam. The detector response was found to be linear in the concentration range of 100 -500 µg/ml for Paracetamol and 10 -50 µg/ml for Lornoxicam.

Two simple, efficient and reproducible methods for the determination of doxofylline in tablets have been developed using reverse phase high performance liquid chromatography and high performance thin layer chromatography. The elution in HPLC was done using a mobile phase consisting of acetonitrile and methanol (70:30 v/v) on intersil C18, 4.6 × 250 mm analytical column with flow rate of 1 ml/min with detection at 208 nm. The elution time was 3.06±0.02 min. The development in HPTLC was carried out using silicagel 60 Merck pre-coated plates and mobile phase consisting of acetonitrile and methanol (7:3 v/v). The detection was carried out at 208 nm. External standard calibration was employed for quantitation by both methods. The linearity range was 25-125 µg/ml and 100-600 ng/spot for HPLC and HPTLC methods respectively. Fig 1: Chromatogram of Doxofylline showing retention time at 3.07 min

A Simple, fast and precise high performance thin layer chromatographic method has been developed for the simultaneous determination of losartan and perindopril in tablet. Separation was carried out on precoated TLC plates, coated with silica gel 60 F 254. The separation was done using a mobile phase toluene: acetonitrile: formic acid (5:5:0.3 v/v/v). After development, the chromatoplates were scanned at 215 nm. The Rf value of losartan and perindopril was found to be 0.55 and 0.27 respectively. The results of the analysis have been validated statistically and by recovery studies.

A simple, specific, accurate and precise reverse phase high pressure liquid chromatographic method has been developed for the simultaneous determination of Ramipril and Amlodipine besylate from combined dosage form by reverse phase C18 column (BDS, C18, 5μ, 250mm x 4.6mm). The sample was analysed using (1.36gm of potassium dihydrogen ortho phosphate and 1ml of triethy amine in 1000ml of water) Buffer:Acetonitrile in the ratio of 45:55(pH adjusted to 6.5 with Orthrophosphric acid) as a mobile phase at a flow rate of 1ml/min and detection at 230nm. The retention time for Ramipril and Amlodipine besylate was found to be 2.6 and 4.3 min respectively, and recoveries from combined dosage form were between 98 and 102%. The method can be used for estimation of combination of these drugs in combined dosage form.

The present work reports a method for the simultaneous determination of Paracetamol and Lornoxicam in binary mixture. The method was based on HPTLC separation of the two drugs followed by densitometric measurements of their spots at 254nm. The separation was carried out using Ethyl acetate: Methanol: Chloroform: Triethylamine in the ratio of 9:0.5:0.5:0.2 v/v/v/v as mobile phase on Merck HPTLC aluminium sheets of silica gel 60 GF254. The linearity was in the range of 0.5-2.5 µg/spot for both the drugs. Proposed method has been successfully applied to pharmaceutical formulation. No chromatographic interference from the tablet excipients was found. The method was validated in terms of precision, robustness, recovery and limits of detection and quantitation.

Objective: In the present study, a spectrophotometric method that does not require prior separation for simultaneous estimation of three paracetamol, cetirizine and dextromethorphan in tablet formulation have been reported. simultaneous estimation of paracetamol, cetirizine and dextromethorphan from pure and dosage form.

A simple, fast, precise and accurate liquid chromatographic method was developed for the simultaneous estimation of salbutamol, ambroxol and theophylline in tablets. This combination is used for the treatment of bronchial asthma. Drugs are chromatographed on a reverse phase Hypersil C18 column using mobile phase, phosphate buffer (pH 7.0), methanol and acetonitrile in the ratio 40:30:30 (v/v). The retention time of salbutamol, ambroxol and theophylline was 3.07, 4.91 and 1.77 min, respectively. The validation of the proposed method was also carried out. The method was found to be linear (correlation coefficient r > 0.999), precise (relative standard deviation: 0.42 % for salbutamol, 0.61 % for ambroxol and 0.73 % for theophylline), accurate (overall average recovery yields: 99 % for salbutamol, 101.2 % for ambroxol and 99.8 % for theophylline) and selective. Due to its simplicity and accuracy, the proposed method can be used for routine quality control analysis of these drugs in combination tablets.

The present work reports a method for the simultaneous determination of tizanidine and valdecoxib in binary mixture. The method was based on HPTLC separation of the two drugs followed by densitometric measurements of their spots at 254 nm. The separation was carried out using methanol:acetone:toluene (4:4:2, v/v/v) as mobile phase on Merck HPTLC aluminium sheets of silica gel 60 F254. The linearity was in the range of 10-100 and 100-1000 ng/spot for tizanidine and valdecoxib, respectively. Proposed method has been successively applied to pharmaceutical formulation. No chromatographic interference from the tablet excipients was found. The method was validated in terms of precision, robustness, recovery and limits of detection and quantitation.