The discovery of inducible cyclooxygenase-2 enzyme led to the development of a new generation of nonsteroidal antiinflammatory drugs, most commonly known as coxibs. Within a short span of time, coxibs became the most widely prescribed drugs (with annual sale of more than $5 billion in the US) due to their gastroprotective effect. But immediate and voluntarily withdrawal of rofecoxib due to excessive cardiac morbidity reported with its chronic use has raised questions about their superior overall safety profile. This review summarizes the evidence regarding the use of coxibs and associated cardiovascular risk; mechanisms underlying the coxibs-mediated cardiovascular risk and other thrombotic events, evidence for a differential effect on cardiotoxicity among coxibs, and recent trends in the antiinflammatory therapy.

A therapeutically significant drug may have limited utilization in clinical practice because of poor organoleptic properties, poor bioavailability, short duration of action, nonspecificity, incomplete absorption, poor aqueous solubility, high first-pass metabolism or other adverse effects. There is a great emphasis on research to discover methods aimed at improving their therapeutic efficacy by minimizing or eliminating these undesirable properties. Sometimes, an adequate pharmaceutical formulation can overcome these drawbacks, but often the galenic formulation is inoperant and a chemical modification of active molecule is necessary to correct its pharmacokinetic insufficiencies. This chemical formulation process, whose objective is to convert an interesting active molecule into a clinically acceptable drug, often involves the so-called 'Prodrug design.' Mutual prodrug is a type of carrier-linked prodrug, where the carrier used is another biologically active drug instead of some inert molecule. A mutual prodrug consists of two pharmacologically active agents coupled together so that each acts as a promoiety for the other agent and vice versa. Mutual prodrug design is really no different from the general drug discovery process, in which a unique substance is observed to have desirable pharmacological effects, and studies of its properties lead to the design of better drugs. It is a very fruitful area of research, and its introduction in human therapy has given successful results in improving the clinical and therapeutic effectiveness of drugs suffering from some undesirable properties that otherwise hinder their clinical usefulness. The present article takes a review of various applications of mutual prodrugs and the developments in this field during the last few decades.

Pulsatile systems are gaining a lot of interest as they deliver the drug at the right site of action at the right time and in the right amount, thus providing spatial and temporal delivery and increasing patient compliance. These systems are designed according to the circadian rhythm of the body. The principle rationale for the use of pulsatile release is for the drugs where a constant drug release, i.e., a zero-order release is not desired. The release of the drug as a pulse after a lag time has to be designed in such a way that a complete and rapid drug release follows the lag time. Various systems like capsular systems, osmotic systems, single- and multiple-unit systems based on the use of soluble or erodible polymer coating and use of rupturable membranes have been dealt with in the article. It summarizes the latest technological developments, formulation parameters, and release profiles of these systems. Products available as once-a-daily formulation based on Pulsatile release like Pulsincap®, Ritalin®, and Pulsys® are also covered in the review. These systems are beneficial for the drugs having chronopharmacological behaviour where night time dosing is required and for the drugs having high first-pass effect and having specific site of absorption in GIT. Drugs used in asthmatic patients and patients suffering from rheumatoid arthritis are also discussed along with many other examples.

Carbamazepine was complexed with β -cyclodextrin in an attempt to enhance the solubility features of the drug. Phase solubility studies revealed a linear relationship between carbamazepine solubility and b-cyclodextrin concentration. The value of the stability constant (405.42 M ^-1sub ) calculated from the phase solubility diagram indicated that the complexes were adequately stable. Carbamazepine-β -cyclodextrin complex prepared by kneading method was used to produce dispersible tablets. A 2 ³sub factorial design was employed to investigate the effect of factors such as amount of binder, hardness and type of disintegrant on the tablet disintegration time and dissolution rate. Mathematical models containing only the significant factors influencing each response were generated using multiple linear regression and analysis of variance. The three main factors studied had a significant influence on both the response parameters. In addition to the main factors, the two-way interaction factors also showed a significant effect on the release rate. Type of disintegrant emerged as the main effect with the highest statistical significance affecting both the responses. Two formulations with a combination of factors within the experimental domain were developed and evaluated to validate the mathematical models. The predicted values were found to agree with the experimental values, confirming the forecasting ability of multi-linear regression and ANOVA.

Oral dosage forms containing 300 mg theophylline in matrix-type tablets were prepared by direct compression method using two kinds of matrices - glycerylbehenate (hydrophobic) and hydroxypropylmethyl cellulose (hydrophilic). The in vitro release kinetics of these formulations were studied at pH 6.8 using the USP dissolution apparatus with the paddle assemble. The kinetics of the dissolution process were studied by analyzing the dissolution data using four kinetic equations - the zero-order equation, the first-order equation, the Higuchi square root equation, and the Hixson-Crowell cube root law. The analysis of the dissolution kinetic data for the theophylline preparations in this study shows that it follows the first-order kinetics, and the release process involves erosion/diffusion and an alteration in the surface area and diameter of the matrix system as well as in the diffusion path length from the matrix drug load during the dissolution process. This relation is best described by the use of both the first-order equation and Hixson-Crowell cube root law.

Several batches of paraffin ointments were prepared and ibuprofen was incorporated into them. Sesame oil, sunflower oil, and oleic acid in different concentrations were incorporated into different batches. Commercial ibuprofen gel was obtained and divided into several batches and different concentrations of sesame oil, sunflower oil, and oleic acid were incorporated into them. The in vitro drug release characteristics through hairless (88 mm) rat skin was carried out by using modified Insertion cell designed in our laboratory. The cell was placed into a borosil beaker containing 50 ml of pH 7.4 phosphate buffer as the diffusion fluid. The beaker was placed over the magnetic stirrer, which was maintained at 37±0.5° to maintain the temperature of diffusion fluid. The released drug content at predetermined time interval was measured using U-V-double beam spectrophotometer at 272 nm. The drug release was raised with increase in oil concentration.

Simple, sensitive, and specific spectrophotometric methods were developed and validated for quantitation of diclofenac potassium and tizanidine in tablet dosage form. Three new analytical methods were developed based on the simultaneous estimation of drugs in a binary mixture without previous separation. In multiwavelength technique, the binary mixture was determined by mixed standards and three sampling wavelengths of 277 nm, 295 nm (isobestic point), and 320 nm. In simultaneous equation method, the drugs were determined by using the absorptivity values of diclofenac potassium and tizanidine at selected wavelengths, viz., 277 nm and 320.3 nm. The standard deviation value for the validation parameters was found to be between 0.08 and 0.68 for multiwavelength technique and between 0.069 and 1.23 for simultaneous equation method. The graphical absorbance ratio method was performed by absorbances at 277 nm, 295 nm (isobestic point), and 320.4 nm of their mixture. These three methods are simple, accurate, and rapid, and they require no preliminary separation and can therefore be used for routine analysis of both drugs in quality control laboratories.

This present work is an investigation of anticancer activities of the nitrogen mustards possessing quinazolinone, benzimidazole, benzoxazole, and benzothiazole nuclei by the three-dimensional Quantitative Structure Activity paradigm, Comparative Molecular Field Analysis. A total of 39 compounds were modelled in SYBYL 6.7 (Tripos, USA). The molecules were aligned by root-mean-square fit of atoms and field fit of the steric and electrostatic molecular fields and the resulting databases analysed by partial least squares analysis with cross-validation, leave-one-out and no validation to extract the optimum number of components. The analysis was then repeated with bootstrapping to give the final Quantitative Structure Activity Relationship models. Eight compounds, which were kept separately as test set, were used to test the predictive ability of the Comparative Molecular Field Analysis models. Out of the two models generated, one was found to be useful. The predicted activities of the test set were in good agreement with experimentally determined values.

Mechanism of interaction of three isoxazolyl penicillins, cloxacillin sodium, dicloxacillin sodium, and flucloxacillin sodium - with bovine serum albumin has been studied using fluorescence spectroscopic technique. The stoichiometry of the interaction was found to be 1:1, and association constants were of the order of 10 ⁴sub in each case. The nature of drug-protein interaction could be predicted from the thermodynamic parameters for the binding. High positive entropy changes and positive enthalpy changes indicated that hydrophobic interactions are predominantly involved in the binding of these drugs to serum albumin. Binding studies carried out in the presence of hydrophobic probe 1-anilinonaphthalene-8-sulfonate (ANS) showed that the drugs and ANS do not share a common site on the albumin molecule. Stern-Volmer analysis of the fluorescence data showed that both the tryptophan residues of albumin are involved; but they are not fully accessible to the drugs, and static quenching mechanism is operative.

Fractionation of a butanol extract of Senecio cannabifolius Less. led to the isolation of two novel monoterpenoid derivatives, named cannabiside D and cannabiside E, whose structures were determined by spectroscopic analyses as 1-(2-hydroxy-2,6,6-trimethyl-4-β-D- glucosyloxy-cyclohexylidene)-butane-2, 3-dione, 6-Hydroxy-3-(3-O-β-D-glucopyranosyl- but-1-enyl)-2, 4,4-trimethyl-cyclohex-2-enone, along with two known glycosides. All the compounds had antibacterial activity, showing particularly potent activity against Staphylococcus aureus IFO 3060 and Bacillus subtilis .

Chloroform extract of the leaves of Asteracantha longifolia at different doses (250 and 500 mg/kg body weight) was examined on anaemic albino rat for certain haematological parameters like erythrocyte count, leukocyte count, and haemoglobin count. Chloroform extract was found to significantly (b,b1,b2,b3P <0.05) improve erythrocyte and haemoglobin count on the 22nd day (d) after 7 d of continuous cyclophosphamide (3 mg/kg body weight) treatment. Treatment with chloroform extract along with cyclophosphamide was found to significantly ( P <0.001) increase the bone marrow cellularity (11.5×106) as compared to cyclophosphamide alone treated group (6.2×106). Administration of extract increased the number of a-esterase positive cells (1062/4000) in the bone marrow of cyclophosphamide-treated animals, compared to the cyclophosphamide alone treated group (650/4000). The major activity of A. longifolia may be stimulation of stem cell proliferation. The observations that A. longifolia could reduce the cyclophosphamide-induced toxicity may indicate its usefulness in cancer therapy.

A quantitative structure activity relationship study on a series of N-alkyl imidazole analogues was made using combination of various thermodynamic electronic and spatial descriptors. Several statistical expressions were developed using stepwise multiple liner regression analysis. The best quantitative structure activity relationship models were further validated by leave-one-out method of cross-validation. The study revealed that the electronic property, i.e., dipole moment contributed positively, and spatial descriptor (principal moment of inertia at Y axis) contributed negatively. The study suggested that substitution of group at R1 position on imidazole ring with hydrophobic nature and low bulkiness are favourable for the antibacterial activity in the concerned microbes. The quantitative structure activity relationship study provides important structural insights in designing of potent antibacterial agents.

Petroleum ether, chloroform, ethanol, and distilled water extracts of the fruits of the plant Balanites Roxburghii (Balanitaceae) were tested for antifertility activity in female albino rats at a dose of 300 and 600 mg/kg body weight orally. Among these, the ethanol extract was found to be most effective in causing significant abortifacient activity. The antifertility activity was found to be dose dependent and reversible on withdrawal of the treatment. Phytochemical screening of the ethanol extract showed positive tests for the presence of alkaloids, glycosides, saponins, flavones, and phenolic compounds. The histological studies of the uterus and ovary were carried out to confirm the estrogenic activity. Acute toxicity studies of the crude extracts in mice revealed the non-toxic nature of the crude extracts.

The ethanol and aqueous extracts of Tabernaemontana coronaria flowers possessed significant in vitro superoxide, hydroxyl radicals, nitric oxide scavenging, and lipid peroxidation inhibiting activities. The antiinflammatory activity of the ethanol extract was evaluated by carrageenan-induced acute and formalin-induced chronic antiinflammatory models in mice. The extract showed remarkable antiinflammatory activity in both models, comparable to the standard reference drug diclofenac. The results suggest that the antiinflammatory activity of the ethanol extract of T. coronaria is possibly attributed to its free radical scavenging properties.

Tenoxicam is a nonsteroidal antiinflammatory drug, used in the treatment of inflammatory and degenerative disorders of the musculoskeletal system. It is from the oxicam group of nonsteroidal antiinflammatory agents. It is widely prescribed for the treatment of osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, gout, extra-articular disorders, bursitis, tendonitis, and nonarticular rheumatic condition. Tenoxicam has some side effects when taken orally, viz., epigastric pain, heartburn, nausea, diarrhoea, vomiting, peptic ulcer, and hepatic impairment. The aim of this study was to formulate topical gel containing 1% of tenoxicam in 1% carbopol-940 and PEG-4000 and to evaluate it for antiinflammatory activity using carrageenan-induced paw oedema in rats. The studies were conducted on Wistar rats of either sex (160-180 g). The change in oedema volume of the rat hind paw was measured using mercury plethysmometer. The readings were measured in terms of volume displaced in millimetre using a micropipette that has mark to 10 divisions in 1 ml. The carbopol gel formulation of tenoxicam containing 15% of ethanol and 5% of sodium lauryl sulphate was significantly more effective against oedema formation than the other formulation of tenoxicam gel and compared to the marketed product of piroxicam gel. Results suggest that the 1% tenoxicam gel in carbopol-940 inhibited 52% of carrageenan-induced oedema formation as compared with the 44% inhibition obtained with marketed product of piroxicam gel.

With a view to explore the versatile lead molecule 4(3H)-quinazolinones, a series of novel 2-methyl-3-(1'3'4'-thiadiazoyl)-4-(3H) quinazolinones have been synthesised by reacting 2-amino-5-aryl/alkyl-1'3'4'-thiadiazoyl with 2-substituted benzoxazin-2-one. The designed compounds (5a-f) were screened in vitro for antibacterial activity on Staphylococcus aureus , Bacillus subtilis , and Escherichia coli . Antifungal activity was screened against Candida albicans , Aspergillus niger , and Curvularia lunata . Synthesised compounds exhibited both antibacterial and antifungal activity.

Dementia is one of the age-related mental problems and a characteristic symptom of Alzheimer's disease. Nootropic agents are used in situations where there is organic disorder in learning abilities. The present work was undertaken to assess the potential of Ocimum tenuiflorum Linn. as a nootropic and anticholinesterase agent in mice. Ethanol extract of dried whole plant of O. tenuiflorum Linn. ameliorated the amnesic effect of scopolamine (0.4 mg/kg) and aging-induced memory deficits in mice. Passive avoidance paradigm served as the exteroceptive behavioural model. O. tenuiflorum extract increased step-down latency and acetyl cholinesterase inhibition significantly. Hence, O. tenuiflorum can be employed in the treatment of cognitive disorders such as dementia and Alzheimer's disease.

Two simple spectrophotometric methods for the determination of aspirin and clopidogrel in pharmaceutical formulations have been developed. First method is based on the additivity of absorbances. Second method is based on the determination of graphical absorbance ratio at two selected wavelengths, one being the isoabsorptive point for the two drugs (225 nm) and the other being the absorption maximum of hydrolysed aspirin (235.7 nm). Beer Lambert's law is obeyed for both the drugs in the concentration range 4-18 mg/ml. Both the methods were found to be simple, rapid, accurate and can be adopted in routine analysis of drugs in formulations. The accuracy and reproducibility of the proposed method was statistically validated by recovery studies.

A simple and sensitive method for the determination of methylene chloride as residual solvent was developed and validated on gas liquid chromatograph fitted with flame ionization detector. The carrier gas was nitrogen, and separation was carried out on BP 5 capillary column consisting of 5% phenyl and 95% dimethyl polysiloxane stationary phase. The retention time for methylene chloride was 5.4 min. The method was extended for determination of the methylene chloride organic volatile impurity in the marketed formulations of ciprofloxacin hydrochloride, norfloxacin, pefloxacin and ofloxacin.

A simple, accurate, economical, and reproducible method for simultaneous estimation of valdecoxib and paracetamol in two-component tablet formulation has been developed. The method of analysis is derivative spectroscopy to eliminate spectral interference by measuring absorbances at two wavelengths 284 nm and 301 nm for valdecoxib and paracetamol respectively. The results obtained in triplicate were validated statistically and by recovery studies.

A simple, accurate, rapid, and sensitive visible spectrophotometric method has been developed for the determination of valdecoxib in pure and pharmaceutical dosage forms. The method is based on the reaction of valdecoxib with potassium permanganate to form a bluish green coloured chromogen with an absorption maximum at 610 nm. Beer's law was obeyed in the range of 5-25 mg/ml. The proposed method has been successfully applied to the analysis of the bulk drug and its dosage forms

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 3.67x10⁴ l/mol.cm and maximum absorbance at 303 nm in 0.1 M sodium hydroxide with apparent molar absorptivity of 3.60x10⁴ 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 1.06x10⁵ l/mol.cm. Beer′s law was obeyed in the concentration range of 5-25 g/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.

Condensation of substituted benzaldehydes with primary aryl amines gave a series of Schiff bases(1a ₁ -e ₁ ,a ₂ ,b ₂ ,d ₂ ,b ₃ -e ₃ ) which, on reaction with thioglycolic acid, resulted in the formation of the corresponding 4-thiazolidinones(2a ₁ -e ₁ ,a ₂ ,b ₂ ,d ₂ ,b ₃ -e ₃ ). These compounds, on condensation with substituted benzaldehydes in anhydrous sodium acetate, furnished 2-phenyl(substituted)-3-aryl-5-benzilidine(substituted)-thiazolidine-4-ones(3a ₁ -e ₁ ,a ₂ ,b ₂ ,d ₂ , b ₃ -e ₃ ). The latter, on heating with 2,4-dinitrophenyl hydrazine in anhydrous sodium acetate, gave the title compounds(4a ₁ -e ₁ ,a ₂ ,b ₂ ,d ₂ ,b ₃ -e ₃ ). The structures have been established on the basis of elemental analysis and spectral data. The title compounds have been screened in vitro for their possible antibacterial activity

The wound healing efficacy of aqueous and methanolic leaf extracts of Leucas hirta was evaluated in excision, incision and dead space wound models. The parameters studied include rate of wound contraction, period of complete epithelialization, tensile strength of incision wound and granulation tissue, granulation tissue dry weight, hydroxyproline content and histological studies of granulation tissue. Among the two extracts studied, methanol leaf extract was found to possess significant wound healing activity followed by aqueous extract, which was evidenced by decrease in the period of epithelialization, increase in the rate of wound contraction, skin breaking strength, granulation tissue dry weight, hydroxyproline content and breaking strength of granulation tissue. Histopathological study of the granulation tissue evidenced increased collagenation when compared to control group of animals.

A new simple and sensitive spectrophotometric method was developed on the basis of a colour reaction of cefoperazone sodium with Folin Ciocalteu's phenol reagent in presence of sodium carbonate, and it is stable for 20 min. The method is based on the formation of blue coloured chromophore that has an absorption maxima at 668 nm and obeys Beer's law in the concentration range of 8/40 µg/ml. Results of the analysis were validated statistically and by recovery studies. The method was found to be suitable for routine determination of cefoperazone sodium.

A simple, sensitive, rapid, accurate, and precise spectrophotometric method has been developed for estimation of gatifloxacin in pharmaceutical dosage forms. The method is based on formation of orange coloured chromogen due to reaction of gatifloxacin with ferric nitrate reagent solution, which exhibits maximum absorption at 470 nm against blank. Stability of chromogen was found up to 1 h, and chromogen obeyed linearity over 20-200 µg/ml.

A simple, precise, accurate, and validated reverse phase HPLC method has been developed for the simultaneous estimation of aceclofenac and paracetamol in tablet by reverse phase C-18 column (Intersile 4.6 mm×25 cm, 10 µm) using acetonitrile: 50 mM NaH ₂ PO ₄ in a ratio of 65:35 (pH adjusted to 3.0 with orthophosphoric acid) as a mobile phase at a flow rate of 1.5 ml/min and detection at 276 nm. The retention time for aceclofenac and paracetamol was found to be 1.58 and 4.01 min respectively, and recoveries from tablet were between 99 and 101%. The method can be used for estimation of combination of these drugs in tablets.

The methanol extracts of Mahonia leschenaultii takeda (Berberidaceae) root and root bark were tested for antibacterial potential against Escherichia coli (NCIM 2068), Pseudomonas aeruginosa (NCIM 2053), Staphylococcus aureus (NCIM 2492), and Staphylococcus epidermitis (NCIM 2493) on nutrient agar medium and nutrient broth using ampicillin trihydrate as standard drug. For antifungal study, stains used were Trichophytons lignorum (NCIM 1195) and Candida crusei (NCIM 3129) on Sabourauds dextrose agar (SDA) and Sabourauds dextrose broth (SDB) by cup plate method using amphotericin B as standard drug. The results showed that all extracts exhibited significant activity against all the selected strains of bacteria and relatively more against Staphylococcus epidermitis . The antifugal activity was less significant when compared with antibacterial activity.

A reverse phase liquid chromatographic method was developed for the simultaneous estimation of tizanidine and valdecoxib in tablets. This method is based on using a Hypersil BDS C₁₈ column using a mobile phase of 10 mM octane sulphonic acid sodium salt and 0.3% triethylamine (pH adjusted to 3.5±0.1 with orthophosphoric acid) and acetonitrile in the ratio of 70:30 v/v. Rofecoxib was used as an internal standard. The retention time of tizanidine, valdecoxib, and rofecoxib were 3.15, 10.92, and 16.24 min respectively. The method was found to be linear (correlation coefficient r>0.999), precise (Residual standard deviation: 0.62% for tizanidine, 0.86% for valdecoxib), accurate (overall average recovery yields: 98.7% for tizanidine, 99.2% for valdecoxib), and selective.

Simple, accurate, and precise UV-Spectrophotometric method was developed for the estimation of atenolol and amlodipine besylate in tablets. The standard stock solutions of atenolol and amlodipine besylate as well as mixed standard solution were diluted appropriately. The absorption spectra of the resultant solutions of atenolol and mixed standard solution were obtained by scanning between 264 to 308 nm against solvent blank. The spectra thus obtained was derivatised to obtain third order derivative [Dl (N) = 2] spectra. A tangent was drawn through the two satellite minima (DL 278.5 nm and DH ~286 nm). An altitude was drawn through this tangent to the inverted maxima termed as DB (~282 nm). The peak height was measured in mm and plotted against respective concentrations. The absorbances of the resultant solutions of amlodipine besylate as well as mixed standard solutions were read at 361 nm. A graph of concentration versus peak height in mm for atenolol was constructed. The E1cm value was calculated for amlodipine besylate at 361 nm. Atenolol was estimated in tablets by interpolation on the calibration curve. The concentration of amlodipine besylate in tablets was determined by E1cm. The proposed analytical method was found to be accurate, precise, and reproducible.

Two simple, sensitive, accurate, and rapid visible spectrophotometric methods have been developed for the estimation of metoclopramide hydrochloride in tablets. Method A is based on the reaction of drug with 4-dimethyl amino-benzaldehyde (Ehrlich reagent) to yield a yellow colour Schiff's base, which shows maximum absorbance at 438 nm against reagent blank, while method B is based on diazotisation of primary amine group of metoclopramide hydrochloride with sodium nitrite and hydrochloric acid followed by coupling with β-napthol (in alkaline medium) to form a red colour dye, which shows maximum absorbance at 553 nm against reagent blank. Beer's law was obeyed in the concentration range of 10-100 µg/ml in method A and 1-10 µg/ml in method B. Results of the analysis were validated statistically and by recovery studies.

Terminalia catappa L. (tropical almond), family Combretaceae, is a large deciduous tree, originally from India. It thrives as an ornamental tree in many tropical cities of the world. The present work highlights the use of the acidified methanol extract of the outer cover of Terminalia catappa fruits as an acid-base indicator in different types of acid-base titrations. It is found to be a very useful, economical, simple, and accurate indicator for said titrations.

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 4.6x150 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 mg/ml for raloxifene hydrochloride.

Three simple and sensitive spectrophotometric methods (I, II, and III) in the visible region have been developed for the quantitative estimation of nitazoxanide in bulk drug and pharmaceutical formulations. These methods are based on the reaction of reduced nitazoxanide with p-dimethylaminobenzaldehyde, p-dimethylaminocinnamaldehyde and vanillin in acidic conditions to form pink, orange red, and orange yellow coloured chromogens with absorption maxima at 559 nm, 534.5 nm, and 475 nm respectively. The reduction of nitazoxanide was carried out with zinc granules and 5 N hydrochloric acid at room temperature in methanol. Beer's law is obeyed in the concentration range of 5-25 mg/ml, 5-25 mg/ml, and 10-50 mg/ml respectively. The results of analysis have been validated statistically and by recovery studies. The methods were found to be accurate, precise, rapid, and economic. The results are comparable with those obtained with visible spectrophotometric method in methanol at 402 nm.

A simple, economical, fast, and precise reverse phase high performance liquid chromatographic method has been developed for the determination of rabiprazole in tablet dosage form. A C 18 Hypersil (5 micron 25 cm×4.6 mm) column from Thermo, in isocratic mode with mobile phase acetonitrile:phosphate buffer:methanol(50:40:10) The flow rate is 1.4 ml/min, and effluent was monitored at 232 nm.