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In the current scenario, green technologies in chemistry and various fields create attention to every researcher. The green synthesis provides environmentally and eco-friendly raw materials and intermediate products, making a simple process without using harmful and toxic reactants. Amino acids are one of the reactants from which the intermediates or excipients can be made using the straightforward methodology, and these are utilized in drug delivery via a different route of Administration. By employing such medication at a cellular level, we can eliminate the adverse events and toxicity of chemically synthesized excipients and achieve a better therapeutic effect. In the present paper, Arginine was reviewed as the starting material from which the greener excipients can be synthesized, and these materials were employed for drug delivery systems. However, some of the synthetic processes employed chemicals, and also usage of the synthesized green material in the formulation of different dosage forms may require proper guidelines, but still, the research is going on for the application of green excipients for therapeutic purposes. Moreover, Arginine, as such, is an amino acid. It can also be utilized in different formulations as an active ingredient, which was also emphasized in the review paper from past research and patents. This review aims to be comprehensive and have general interest for chemists as it involves the various routes by which excipients were synthesized and the study, including the properties of different excipients and their application.

The application of l -arginine, the nonessential amino acid, as in pharmaceutical and cosmetics is raised as it shows the number of advantages for internal and external, applications. But its hydrophilic nature and lower partition co-efficient value limit its penetration through the skin. From the different approaches for topical drug delivery systems, solid lipid nanoparticles are a promising vehicle to carry the drug molecule at the appropriate site of absorption and also ensures the fast therapeutic action. With ability to incorporate lipophilic as well as a hydrophilic molecule. The present investigation aimed to implement the Quality by design concept for the development of SLNs incorporated with arginine molecule for its application on skin in the form of cosmoceutical formulation. The developed formulation will enhance the blood circulation of skin cells and hence beneficial for skin as cosmoceutical dosage form. To enhance the loading of drug molecule in a lipolphilic environment like solid lipid, insitu ion-pairing was carried out using an optimum concentration of oleic acid. The optimization was done by QbD approach considering concentration of poloxamer 188, oleic acid and sonication amplitude as the critical processing parameters. Average particle size and % drug loading were taken as critical product quality attributes using 23 full factorial design. The characterization of freeze dried solid lipid nanoparticles are investigated by transmission electron microscopy, x-ray diffraction study, differential scanning calorimetry and fourier transform infrared spectroscopy. Finally, an in-vitro and ex-vivo drug diffusion stuies were carried out to check the permeation of arginine. The optimized SLN formulation were successfully developed having lower particle size and higher % drug loading with effective skin penetration parameters to achieve the therapeutic benefits of Arginine.

Background: Balofloxacin is a third generation fluoroquinolone with a broad antibacterial spectrum ranging from gram-positive bacteria to gram-negative bacteria. It is used in treatment of uncomplicated urinary tract infections. No stability indicating analytical method has been reported for BFX. Also stress degradation studies of Balofloxacin were not found in literature. Objective: To develop and validate a stability indicating RP-HPLC method for estimation of Balofloxacin in presence of its hydrolytic degra­dation products. Materials and Method: The chromatographic separation was performed using C 18 , Grace Smart column (250 x 4.6 mm), 5 μm as the stationary phase and Water: Acetonitrile: Tri ethylamine (72:28:1 v/v/v), pH adjusted to 3.0 using ortho-phosphoric acid as mobile phase with detec­tion wavelength 294 nm. The developed method was validated according to ICH Q2R1 guideline. Balofloxacin was subjected to degradation in acidic, alkaline and neutral conditions. Results and Discussion: The linearity was established over concentration range of 20-100 μg/ml with correlation coefficient r 2 = 0.9979. Recovery of drug was achieved in the range of 99.19–101.65%. Limit of Detection and Limit of Quantitation was found to be 4.13 and 12.51 μg/ml. Balofloxacin was found to be stable under alkaline and neutral conditions, while it degraded under acidic hydrolytic condition. The retention times for Balofloxacin and its acid degradation product were found to be 7.0 ± 0.1 and 5.7 ± 0.1 minutes, respectively. Application: The developed RP-HPLC method was applied for estimation of Balofloxacin in its tablet dosage forms and results were found to be in good agreement with the labeled claim. The method was also applied for degradation kinetic study of Balofloxacin in acidic medium. Conclusion: The developed RP-HPLC method was found to be accurate, precise, specific and sensitive. It can be applied for routine analysis (assay) of tablets containing Balofloxa­cin. The degradation of Balofloxacin in all conditions was found to be first order and highest degradation was found in 2.0 N HCl at 75°C. Key words: Stability indicating HPLC method, Balofloxacin (BFX), Degradation products, Degradation kinetic study, Design expert software–9.

A HPTLC method for the simultaneous estimation of aliskiren, amlodipine, and hydrochlorothiazide in the combination dosage form is proposed. Silica gel 60 F254 precoated plates were used as the stationary phase, whereas Quality by design approach was applied for the efficient separation of the drugs through which a simple mobile phase composition Ethyl acetate:Methanol:Ammonia (7.5:2.8:0.22, v/v/v) was finalized. The RF values optimized were 0.43 ± 0.01, 0.29 ± 0.01, and 0.65 ± 0.01 for aliskiren, amlodipine, and hydrochlorothiazide, respectively. The densitometric analysis was carried out at 229 nm. The method was linear in the range of 1500–5250 ng spot−1 for aliskiren, 50–175 ng spot−1 for amlodipine, and 125–432.5 ng spot−1 for hydrochlorothiazide. The method was validated as per the International Conference on Harmonization guidelines and the RSD (%) was within the acceptable criterion indicating the method is accurate and precise. The LOD and LOQ were found to be 133.38 ng spot−1 and 404.19 ng spot−...

A simple, sensitive, precise, and stability-indicating high-performance thin-layer chromatographic method has been developed and validated for the quantitative determination of pitavastatin calcium (PTV) in a pharmaceutical dosage form in the presence of its degradation products. The stability of PTV was investigated under different stress conditions, including hydrolytic, oxidative, photolytic, and thermal, as recommended by the International Conference on Harmonization guidelines. PTV was separated on aluminum-backed silica gel 60 F254 high-performance thin-layer chromatography (HPTLC) plates as a stationary phase with ethyl acetate–methanol–toluene–glacial acetic acid (4:1:5:0.1, v/v/v/v) as a mobile phase. Regression analysis data for the calibration plots were indicative of good linear relationships between responses and concentration over the range 25–150 ng per band. The method was validated for linearity, precision, accuracy, robustness, specificity, and sensitivity. The drug was subjected to stre...

Two simple and accurate methods to determine atorvastatin calcium and ramipril in capsule dosage forms were developed and validated using HPLC and HPTLC. The HPLC separation was achieved on a Phenomenex Luna C18 column (250 ⨯ 4.6 mm id, 5 µm) in the isocratic mode using 0.1% phosphoric acidacetonitrile (38 + 62, v/v), pH 3.5 ± 0.05, mobile phase at a flow rate of 1 mL/min. The retention times were 6.42 and 2.86 min for atorvastatin calcium and ramipril, respectively. Quantification was achieved with a photodiode array detector set at 210 nm over the concentration range of 0.5-5 µg/mL for each, with mean recoveries (at three concentration levels) of 100.06 ± 0.49% and 99.95 ± 0.63% RSD for atorvastatin calcium and ramipril, respectively. The HPTLC separation was achieved on silica gel 60 F254 HPTLC plates using methanolbenzeneglacial acetic acid (19.6 + 80.0 + 0.4, v/v/v) as the mobile phase. The Rf values were 0.40 and 0.20 for atorvastatin calcium and ramipril, respectively. Quantification was achieved with UV densitometry at 210 nm over the concentration range of 50500 ng/spot for each, with mean recoveries (at three concentration levels) of 99.98 ± 0.75% and 99.87 ± 0.83% RSD for atorvastatin calcium and ramipril, respectively. Both methods were validated according to International Conference on Harmonization guidelines and found to be simple, specific, accurate, precise, and robust. The mean assay percentages for atorvastatin calcium and ramipril were 99.90 and 99.55% for HPLC and 99.91 and 99.47% for HPTLC, respectively. The methods were successfully applied for the determination of atorvastatin calcium and ramipril in capsule dosage forms without any interference from common excipients.

A simple, sensitive, accurate, and precise high-performance thinlayer chromatographic method has been established for simultaneous analysis of atorvastatin calcium, ramipril, and aspirin in a capsule dosage form. The compounds were separated on silica gel with methanol-benzene-ethyl acetate-glacial acetic acid 0.36:5.6:4.0: 0.04 (v/v) as mobile phase. Ultra-violet detection was performed at 210 nm. The RF values were approximately 0.38, 0.06, and 0.86 for atorvastatin calcium, ramipril, and aspirin, respectively. The method was validated for linearity, accuracy, precision, limits of detection and quantification, and robustness. The linearity ranges were 100–600 ng per band for atorvastatin calcium, 50–300 ng per band for ramipril, and 500–3000 ng per band for aspirin. Mean recoveries were 99.97 ± 0.07%, 100.01 ± 0.10%, and 100.02 ± 0.06 % for atorvastatin calcium, ramipril, and aspirin, respectively. Limits of detection (LOD) were 4.88 ng for atorvastatin calcium, 2.91 ng for ramipril, and 18.63 ng for aspirin. Salicylic acid (RF ~ 0.72) was found as an impurity in the capsule dosage form. The proposed method can be used for analysis of these drugs in combined dosage forms.

Two simple and accurate methods for the determination of pitavastatin calcium (PIT) in tablet dosage forms were developed and validated using column liquid chromatography (LC) and UV spectrophotometry. The LC separation was achieved on a Phenomenex Luna C18 column (250 mm, 4.6 mm id, 5 m) in the isocratic mode using acetonitrilewatertriethylamine (80 + 19.8 + 0.2, v/v/v), adjusted to pH 3.5 0.05 with orthophosphoric acid, as the mobile phase at a flow rate of 1.5 mL/min. The retention time was 5.70 min. Both the methods were performed at 238 nm, the wavelength of maximum absorbance of PIT in methanol. In the LC method, quantification was achieved with a photodiode array detector over the concentration range of 0.12.5 g/mL with a mean recovery of 100.26 0.75. In the UV method, quantification was achieved over the concentration range of 220 g/mL with mean recovery of 99.65 1.24. Both methods were validated, and the results were compared statistically. They were found to be simple, specific, accurate, and precise. The methods were successfully applied for the determination of PIT in tablet dosage form without any interference from common excipients.

A simple, sensitive, precise and accurate reversed phase liquid chromatographic method has been developed for the simultaneous estimation of atorvastatin (AT) calcium, ramipril (RA) and aspirin (AS) from capsule dosage form. The method was developed using a Phenomenex Luna C18 (250 mm, 4.6 mm i.d., 5 µm) column with a mobile phase consisting of 0.1%, orthophosphoric acid buffer:acetonitrile:methanol (45:50:5 v/v/v), pH 3.3, at a flow rate of 1 mL min−1. Detection was carried out with ultra-violet detection at 210 nm. The retention times were about 12.19, 2.35, and 3.95 min for AT calcium, RA and AS, respectively. The developed method was validated for linearity, accuracy, precision, limit of detection, limit of quantitation and robustness. The linearity ranges were 1–6 µg mL−1 for AT calcium, 0.5–3 µg mL−1 for RA and 7.5–45 µg mL−1 for AS with mean recoveries of 100.59 ± 0.68, 100.62 ± 0.83 and 100.49 ± 0.73% for AT calcium, RA and AS, respectively. Limit of detection obtained were 29.85 ng mL−1 for AT calcium, 4.71 ng mL−1 for RA and 85.13 ng mL−1 for AS. Impurity of salicylic acid was found in capsule dosage form at the retention time of about 4.84 min. The proposed method can be used for the estimation of these drugs in combined dosage forms.

This paper describes a validated high-performance thin-layer chromatography (HPTLC) method for simultaneous estimation of rabeprazole (RA) and domperidone (DO) in pure powder and in capsule formulations. An HPTLC method separation is achieved on an aluminum sheet of silica gel 60F(254) using ethyl acetate-methanol-benzene-acetonitrile (30:20:30:20 v/v) as mobile phase. Quantitation is achieved with UV detection at 287 nm over a concentration range of 400-1200 ng/spot and 600-1800 ng/spot with mean recovery of 99.82 +/- 0.74 and 99.43 +/- 0.68 for RA and DO, respectively, in the HPTLC method. This method is simple, precise, and sensitive, and it is applicable for the simultaneous determination of RA and DO in pure powder and in capsule formulation.

A sensitive, selective, precise, and stability‐indicating high performance thin layer chromatography (HPTLC) method for analysis of satranidazole both as a bulk drug and in formulations was developed and validated. The method employed TLC aluminium plates precoated with silica gel 60F‐254 as the stationary phase. The solvent system consisted of toluene/acetonitrile (60:40, v/v). Densitometric analysis of satranidazole was carried out in the absorbance mode at 314 nm. This system was found to give compact spots for satranidazole (R f value of 0.53±0.02, for six replicates). Satranidazole was subjected to acid and alkaline hydrolysis, oxidation, and photo degradation. The drug undergoes degradation under acidic and basic conditions, oxidation, and photo degradation. Also, the degraded products were well resolved from the pure drug with significantly different R f values. The method was validated for linearity, precision, limit of detection (LOD), limit of quantitation (LOQ), and accuracy. Linearity...

A rapid, simple, and sensitive HPLC and a densitometric HPTLC method for the determination of omeprazole and domperidone in capsule formulations were developed and validated. For HPLC, the separation of components was achieved on a Phenomenex Rp‐C18 column. Isocratic elution with a mobile phase consisting of 0.01 M pH 6.5, ammonium acetate buffer: methanol:acetonitrile (40:30:30 v/v, pH 7.44±0.02), at a flow rate 1.0 mL/min was employed. Rabeprazole was used as the internal standard. In densitometric HPTLC, separation was achieved on aluminum sheets of silica gel 60F254 using ethyl acetate:methanol:benzene (40:20:40 v/v) as mobile phase. Linear concentration range of HPLC and HPTLC methods were between 400–2000 ng/mL and 120–360 ng/spot for both the drugs, respectively. In HPLC, the detection limit was 131.27 ng/mL for omeprazole and 131.20 ng/mL for domperidone, the mean analytical recovery in determination of omeprazole and domperidone capsules was 99.14±1.81 for omeprazole and 99.63±1.68 for d...

A simple, sensitive, and precise high performance liquid chromatographic method for the analysis of pantoprazole, rabeprazole, esomeprazole, domperidone and itopride, with ultraviolet detection at 210 nm, has been developed, validated, and used for the determination of compounds in commercial pharmaceutical products. The compounds were well separated on a Hypersil BDS C18 reversed-phase column by use of a mobile phase consisting of 0.05 M, 4.70 pH, potassium dihydrogen phosphate buffer - acetonitrile (720:280 v/v) at a flow rate of 1.0 mL min−1. The linearity ranges were 400–4,000 ng mL−1 for pantoprazole, 200–2,000 ng mL−1 for rabeprazole, 400–4,000 ng mL−1 for esomeprazole, 300–3,000 ng mL−1 for domperidone and 500–5,000 ng mL−1 for itopride. Limits of detection (LOD) obtained were: pantoprazole 147.51 ng mL−1, rabeprazole 65.65 ng mL−1, esomeprazole 131.27 ng mL−1, domperidone 98.33 ng mL−1 and itopride 162.35 ng mL−1. The study showed that reversed-phase liquid chromatography is sensitive and selective for the determination of pantoprazole, rabeprazole, esomeprazole, domperidone and itopride using single mobile phase.

Losartan (LST) is the first orally active nonpeptide angiotensin-II receptor antagonist with an improved safety and tolerability profile. It is prescribed alone or in combination with hydrochlorothiazide (HCTZ) for the treatment of moderate-to-severe hypertension. This paper describes the development of 2 methods that use different techniques, first-derivative spectroscopy and high-performance thin-layer chromatography (HPTLC), to determine LST and HCTZ in the presence of each other. LST and HCTZ in combined preparations were quantitated by using the first-derivative responses at 271.6 nm for LST and 335.0 nm for HCTZ in spectra of their solutions in water. The linearity ranges are 30–70 μg/mL for LST and 7.5–17.5 μg/mL for HCTZ with correlation coefficients of 0.9998 and 0.9997, respectively. In the HPTLC method, a mobile phase of chloroform–methanol–acetone–formic acid (7.5 + 1.5 + 0.5 + 0.03, v/v) and a prewashed Silica Gel G60 F254 TLC plate as the stationary phase were used to resolve LST and HCTZ in a mixture. Two well-separated and sharp peaks for LST and HCTZ were obtained at Rf values of 0.61 ± 0.02 and 0.41 ± 0.02, respectively. LST and HCTZ were quantitated at 254.0 nm. The linearity ranges obtained for the HPTLC method are 400–1200 and 100–300 ng/spot with corresponding correlation coefficients of 0.9944 and 0.9979, for LST and HCTZ, respectively. Both methods were validated, and the results were compared statistically. They were found to be accurate, specific, and reproducible. The methods were successfully applied to the estimation of LST and HCTZ in combined tablet formulations.

A sensitive, selective, precise and stability indicating a high-performance thin layer chromatographic method for the analysis of rufinamide (Rf) in bulk drug and its formulations was developed and validated. The method employed thin layer chromatography aluminum plates precoated with silica gel 60 F254 as the stationary phase. The solvent system consisted of chloroform : methanol : glacial acetic acid (9 : 1 : 0.1 v/v/v). This system was found to give compact spots for Rf (Rf value of 0.68 ± 0.02). Rf was subjected to acid and alkali hydrolysis, oxidation, photodegradation and dry heat treatment. Also, the degraded products were well separated from the pure drug. Densitometric analysis of Rf was carried out in the absorbance mode at 210 nm, which is wavelength maxima for the degradant. The linear regression data for the calibration plots showed a good linear relationship with an r(2) of 0.9989 in the concentration range of 1,000-3,500 ng. The method was validated for precision, accuracy, ruggedness and recovery. The limits of detection and quantitation were 196.59 and 595.74 ng spot(-1), respectively. The drug undergoes degradation under acidic and basic conditions. All the peaks of degraded products were resolved from the standard drug with significantly different Rf values.

A simple and sensitive high-performance thin-layer chromatography (HPTLC) method has been developed for the quantitative estimation of gatifloxacin and ornidazole in its combined dosage forms. Gatifloxacin and ornidazole were chromatographed on silica Gel 60 F(254) TLC plate using n-butanol:methanol:ammonia (6 M) (8:1:1.5 v/v) as the mobile phase and scanned at 302 nm using a Camag TLC Scanner 3. The R(f) value of gatifloxacin and ornidazole was found to be 0.21 +/- 0.02 and 0.76 +/- 0.04, respectively. The linearity of gatifloxacin and ornidazole were in the range of 100 - 500 ng/spot and 250 - 1250 ng/spot, respectively. The limit of detection was found to be 40 ng/spot for gatifloxacin and 100 ng/spot for ornidazole. The proposed method was applied for the determination of gatifloxacin and ornidazole in combined dosage forms.

Background Oxcarbazepine (OXZ) is an antiepileptic drug used to treat partial seizures. OXZ is available in dosage forms of tablet (150, 300, and 600 mg) and suspension (300 mg in 5 ml) in India. Children and adults complain that the suspension form has a downside in its stability (8 weeks). Aims The aim of the present investigation was to develop a microemulsion (ME) of OXZ for enhanced solubility and stability of drug in product. Materials and methods An ME comprises isopropyl myristate (oil phase), aerosol OT (a bipolar surfactant), and an aqueous phase comprising ethanol and distilled water in a ratio of 2: 8. Various ratios of oil: surfactant (1: 9 to 9: 1) were taken and the amount of aqueous phase titrated was determined using the water titration method. The data were plotted in a pseudoternary phase diagram and an optimized batch was selected. The batch was characterized by droplet size determination, zeta potential, drug content, and in-vitro dissolution studies. Results Size of the globules was found to be 53.65 and 59.15 nm in both ME 1 and ME 2, respectively; thus, it can also be termed as nanoemulsion. Zeta potential shows that the formulation is stable as it has positive zeta, giving 6.13 and 5.21 mV as zeta for ME 1 and ME 2, respectively. pH and conductance were also close to neutral, and hence the system was biocompatible. Conclusion Finally, on the basis of physicochemical characterization and stability studies, it can be concluded that water-in-oil ME for OXZ will serve as a novel drug delivery system with increased solubilization capacity and increased stability.

Simple, sensitive high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC) methods are developed for the quantitative estimation of rabeprazole and mosapride in their combined pharmaceutical dosage forms. In HPLC, rabeprazole and mosapride are chromatographed using 0.01M 6.5 pH ammonium acetate buffer-methanol-acetonitrile (40:20:40, v/v, pH 5.70+/-0.02) as the mobile phase at a flow rate of 1.0 mL/min. In TLC, the mobile phase is ethyl acetate-methanol-benzene (2:0.5:2.5, v/v). Both the drugs are scanned at 276 nm. The retention times of rabeprazole and mosapride are found to be 4.93+/-0.01 and 9.79+/-0.02, respectively. The Rf values of rabeprazole and mosapride are found to be 0.42+/-0.02 and 0.61+/-0.02, respectively. The linearities of rabeprazole and mosapride are in the range of 400-2000 ng/mL and 300-1500 ng/mL, respectively, for HPLC; in TLC, the linearities of rabeprazole and mosapride are in the range of 400-1200 ng/spot and 300-900 ng/spot, respectively. The limit of detection is found to be 97.7 ng/mL for rabeprazole and 97.6 ng/mL for mosapride in HPLC; in TLC the limit of detection is found to be 132.29 ng/spot for rabeprazole and 98.25 ng/spot for mosapride. The proposed methods can be applied to the determination of rabeprazole and mosapride in combined pharmaceutical products.

Senna is a well-known drug, used in the Ayurvedic and Allopathic systems of medicine, and is a treatment for constipation. The purgative action of senna and its formulations is due to the presence of sennosides A and B. An HPTLC method has been developed for the determination of individual sennosides (A, B, C, D) without any derivatization in marketed formulations (three tablet formulations, two granule formulations and one liquid formulation) and plant materials (senna leaf and pod). The methanolic solution of a sample was applied on a pre-coated silica gel G60 F254 TLC plate (E. Merck.) and was developed using n-propanol: ethyl acetate: water: glacial acetic acid (3:3:2:0.1 v/v) as the mobile phase. The relative band speeds (Rf values) obtained were 0.35, 0.25, 0.61, 0.46 for sennosides A, B, C and D, respectively. The densitometric response was monitored at 366 nm. Calibration curves were found to be linear in the concentration ranges 193–1356, 402–2817, 71–497 and 132–927 ng per spot for sennosides A, B, C, and D, respectively. The correlation coefficients were found to be 0.9978, 0.9987, 0.9939 and 0.9983 respectively for sennosides A, B, C and D. The result obtained with the HPTLC method for total sennoside content was compared with the results using the pharmacopoeial methods (spectrophotometric (British Pharmacopoeia) and spectrofluorimetric (United States Pharmacopeia) using the ‘F’ test). The results revealed no significant difference in the three different methods for estimation of total sennoside. The proposed HPTLC method was found to be simple, specific, precise, accurate and rapid. It can be used for routine quality control of sennosides or senna-containing formulations for individual sennosides.

A rapid, selective and stability-indicating high performance thin layer chromatographic method was developed and validated for the simultaneous estimation of olanzapine and fluoxetine in combined tablet dosage form. Olanzapine and fluoxetine were chromatographed on silica gel 60 F(254) TLC plate using methanol:toluene (4:2 v/v) as the mobile phase and spectrodensitometric scanning-integration was performed at a wavelength of 233 nm using a Camag TLC Scanner III. This system was found to give compact spots for both olanzapine (R(f) value of 0.63+/-0.01) and fluoxetine (R(f) value of 0.31+/-0.01). The polynomial regression data for the calibration plots showed good linear relationship with r(2)=0.9995 in the concentration range of 100-800 ng/spot for olanzapine and 1000-8000 ng/spot for fluoxetine with r(2)=0.9991. The method was validated in terms of linearity, accuracy, precision, recovery and specificity. The limit of detection and the limit of quantification for the olanzapine were found to be 30 and 100 ng/spot, respectively and for fluoxetine 300 and 1000 ng/spot, respectively. Olanzapine and fluoxetine were degraded under acidic, basic and oxidation degradation conditions which showed all the peaks of degraded product were well resolved from the active pharmaceutical ingredient. Both drugs were not further degraded after thermal and photochemical degradation. The method was found to be reproducible and selective for the simultaneous estimation of olanzapine and fluoxetine. As the method could effectively separate the drugs from their degradation products, it can be employed as a stability-indicating method.

A simple, precise and rapid RP-HPLC method was developed for the estimation of etoricoxib in pharmaceutical dosage forms. The method was carried out on a Kromasil 100, RP-C18 column using a mixture of acetonitrile: methanol: 10mM potassium dihydrogen phosphate (pH 3.0 adjusted with orthophosphoric acid). The detection was carried out at 234 nm using rofecoxib as an internal standard. The linearity was found to be 25 to 400 ng/injection with correlation coefficient of 0.9996. The intra-day and inter-day precision (% RSD) were in the range of 0.28 to1.26 and 0.35 to 1.39, respectively. The percentage recovery was found to be 99.52±1.51 to 100.59±1.16. The result of analysis of marketed formulation was found to be 100.32±0.96 to100.95±0.69. The proposed method was successfully applied for the estimation of etoricoxib in pharmaceutical dosage forms.

Two simple, specific, accurate and precise methods, namely, reverse phase high performance liquid chromatography and high performance thin layer chromatography were developed for estimation of nebivolol hydrochloride in tablet dosage form. For the HPLC method, Lichrospher 100 C-18, 5 µm column consisting of 200×4.6 mm i.d. in isocratic mode, with mobile phase containing 50 mM KH 2 PO 4 buffer (pH 3.0±0.1):acetonitrile: (45:55 v/v) was used. The flow rate was 1.0 ml/min and effluent was monitored at 282 nm. The retention time was found to be 3.76±0.02 min. For the high performance thin layer chromatographic method a Camag system comprising of Linnomat V automatic sample applicator, Hamilton syringe, Camag TLC Scanner-3, Camag Win CAT software with stationary phase precoated silica gel 60F 254 and mobile phase consisting of ethyl acetate:toluene:methanol: ammonium hydroxide (1:6:2:0.1 v/v/v/v) were used. The detection of spot was carried out at 282 nm. The R f value was found to be 0.33±0.02. The methods were validated in terms of linearity, accuracy and precision. The linearity curves were found to be linear over 10-150 µg/ml for high performance thin layer chromatography and 100-600 ng/spot for high performance thin layer chromatography. The limit of detection and limit of quantification for high performance thin layer chromatography were found to be 2.0 and 10 µg/ml, respectively, and for the high performance thin layer chromatography, 30 and 100 ng/spot, respectively. The proposed methods were successfully used for estimation of nebivolol hydrochloride in tablet dosage form.

A simple and sensitive spectrophotometric method has been developed for determination of azithromycin in its pharmaceutical dosage forms. In the proposed method, azithromycin is oxidized with potassium permanganate to liberate formaldehyde, which is determined in situ using acetyl acetone, in the presence of ammonium acetate. A yellow coloured chromogen was obtained, having an absorption maxima at 412 nm. The method is found to be linear in the concentration range of 10-75 µg/ml, with regression coefficient of 0.9978. Various reaction parameters such as concentration of potassium permanganate and reagent, time required for oxidation, and maximum colour intensity were optimized. The method was validated, and can be used successfully to assay azithromycin in its pharmaceutical dosage forms viz. tablets, capsules, and injections.

A simple and sensitive spectrophotometric method has been developed for the estimation of lomefloxacin hydrochloride in its marketed formulations. The method is based on the reaction between the drug and the dichlone, in the presence of crotonaldehyde in dimethylsulfoxide, which produces a blue chromogen with absorption maximum at 645 nm. The good agreement with Beer's law was found in the concentration range of 5-100 µg/ml. The optimum reaction conditions and other analytical parameters are evaluated. Statistical comparison of the results with those of reported method shows good agreement, and indicated no significant difference in precision. The proposed method was found to be simple, accurate, and reproducible for the routine analysis of the drug in pharmaceutical dosage forms.

A simple and sensitive spectrophotometric method has been developed for determination of betaxolol hydrochloride in bulk powder, and its pharmaceutical dosage forms. In the proposed method, betaxolol is oxidized with sodium periodate, to liberate formaldehyde, which is determined in situ, using acetyl acetone in the presence of ammonium acetate. A yellow coloured chromogen was obtained having absorption maxima at 405 nm. The method is found to be linear in the concentration range of 5-30 µg/ml, with a regression co-efficient of 0.9997. No significant difference was found between the proposed method and official method, when one tailed and two tailed t-test are applied. Various reaction parameters such as concentration of sodium hydroxide and sodium periodate, time required for oxidation, reagent concentration, and time for maximum colour intensity were optimized. The method was validated, and can be used successfully to assay betaxolol in bulk powder, and its pharmaceutical dosage forms viz. ophthalmic solutions.

A simple and sensitive spectrophotometric method has been developed for determination of roxithromycin in its pharmaceutical dosage forms. In the proposed method, roxithromycin is oxidized with potassium permanganate to liberate formaldehyde, which is determined in situ using acetyl acetone in the presence of ammonium acetate to give a yellow-coloured chromogen with absorption maxima at 412 nm. The method is found to be linear in the concentration range of 10-75 µg/ml with regression coefficient of 0.9987. No significant difference was found between the proposed method and the reported method when two-tailed t-tests are applied. Various reaction parameters, such as concentration of potassium permanganate and reagent, time required for oxidation and maximum colour intensity, were optimized. The method was validated and can be used successfully to assay roxithromycin in its pharmaceutical dosage form, viz, tablets.