Sci. Pharm., Volume 79, Issue 3 (September 2011) – 21 articles , Pages 389-704

Ofloxacin is a synthetic chemotherapeutic antibiotic used for treatment of a variety of bacterial infections, but therapy suffers from low patients’ compliance due to its unpleasant taste. This study was aimed to develop taste masked microspheres of ofloxacin using Eudragit and to prepare orodispersible tablets of the formulated microspheres using natural superdisintegrant. Taste masking Eudragit E100 microspheres were prepared by solvent evaporation technique with an entrapment efficiency ranging from 69.54 ± 1.98 to 86.52 ± 2.25%. DSC revealed no interaction between the drug and polymer. Microspheres prepared at a drug/polymer ratio of 1:4 and 1:5 revealed sufficient flow properties and better taste masking as compared to other ratios. Drug loaded microspheres were formulated as orodispersible tablets using locust bean gum as a natural superdisintegrant offering the advatages of biocompatibility and biodegrad-ability. The wetting time, water absorption ratio and in-vitro disintegration time of the tablets were found to range between 19 ± 2 to 10 ± 3 seconds, 59.11 ± 0.65 to 85.76 ± 0.96 and 22 ± 2 to 10 ± 2 seconds, respectively. The in-vitro ofloxacin release was about 97.25% within 2h. The results obtained from the study suggested the use of eudragit polymer for preparing ofloxacin loaded microspheres with an aim to mask the bitter taste of the drug and furthermore orodispersible tablets could be formulated using locust bean gum as a natural superdisintegrant. Full article

Simvastatin is used in treatment of hypercholesterolemia because it regulates cholesterol synthesis as a result of its β-hydroxy acid acting as an inhibitor of 3-hydroxy-methylglutaryl coenzyme A (HMG-CoA). The present communication deals with synthesis, characterization and development of accurate, precise and sensitive Reverse Phase High Performance Liquid Chromatography (RP-HPLC) method for simultaneous estimation of simvastatin and its synthetic impurities. The impurities methyl ether and β-hydroxy acid of simvastatin were synthesized in the laboratory and characterized by MS, NMR and FT-IR spectroscopy. The separation of simvastatin and its impurities was carried out on an isocratic JASCO RP-HPLC system using KYA TECH HIQ SIL C18 column (150 x 4.6 mm internal diameter, particle size 5 μm) operating at ambient temperature using acetonitrile:water (80:20 v/v) with 0.1% orthophosphoric acid as mobile phase. The method developed for HPLC analysis of three impurities along with simvastatin was validated using ICH Q2B (R1) guidelines and it complied with these guidelines. The results of analysis were found to be in the range of 98.14% to 101.89% for all analytes with acceptable accuracy and precision. The method can be used for detection and quantification of synthetic impurities in bulk or formulations of simvastatin. Full article

In this study, authors developed a simple, sensitive and specific liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for quantification of Amisulpride in human plasma using Amisulpride-d5 as an internal standard (IS). Chromatographic separation was performed on Zorbax Bonus-RP C18, 4.6 x 75 mm, 3.5 μm column with an isocratic mobile phase composed of 0.2% formic acid:methanol (35:65 v/v), at a flow-rate of 0.5 mL/min. Amisulpride, Amisulpride-d₅ was detected at m/z 370.1→242.1 and 375.1→242.1. The drug and the IS were extracted by a liquid-liquid extraction method. The method was validated over a linear concentration range of 2.0–2500.0 ng/mL for Amisulpride with a correlation coefficient of (r²) ≥ 0.9982. This method demonstrated intra- and inter-day precision within 0.9 to 1.7 and 1.5 to 2.8 % and intra- and inter-day accuracy within 98.3 to 101.5 and 96.0 to 101.0 % for Amisulpride. Amisulpride was found to be stable at 3 freeze–thaw cycles, bench top and auto sampler stability studies. The developed method was successfully applied to a pharmacokinetic study. Full article

As part as of the preformulation studies of new 5'-OH derivatives of zidovudine, compounds 2–6, their acid dissociation constants, Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG) curves, X-Ray Powder diffractograms and aqueous stability are reported. A sensitive technique such as differential scanning potentiometry was used to determine the pKa constants of the above mentioned compounds. In addition, pKa values were calculated from theoretical methods, and no significant differences with those of experimental ones were observed. X-Ray Powder Diffractometry data demonstrated that compounds 2–4 were crystalline while 5 and 6 were amorphous. DSC analysis indicated that all of them presented an exothermic decomposition peak above 150 °C which is accompanied by a weight loss in the respective TG curves. The stability of these compounds in aqueous medium at different pH values was investigated, using a validated High Performance Liquid Chromatography (HPLC) method, which demonstrated to be rapid, selective, sensitive, accurate and stability-indicating. Good recovery, linearity and precision were also achieved. For all compounds the aqueous hydrolysis followed a pseudo-first-order kinetics, depending on pH and the union existing between AZT and the associate moiety. The hydrolysis was catalyzed by hydroxide ion in the 7.4–13.2 pH range, while all compounds exhibited pH-independent stability from acidic to neutral media (pHs 1.0–7.4). Full article

A new group of 5,5-diarylhydantoin derivatives bearing a methylsulfonyl COX-2 pharmacophore at the para position of the C-5 phenyl ring were designed and synthesized as selective COX-2 inhibitors. In vitro COX-1/COX-2 inhibition structure-activity relationships identified 5-[4-(methylsulfonyl)phenyl]-5-phenyl-hydantoin (4) as a highly potent and selective COX-2 inhibitor (COX-2 IC50 = 0.077 μM; selectivity index > 1298). It was more selective than the reference drug celecoxib (COX-2 IC50 = 0.060 μM; selectivity index = 405). A molecular modeling study where 4 was docked in the binding site of COX-2 indicated that the p-MeSO2 COX-2 pharmacophore group on the C-5 phenyl ring is oriented in the vicinity of the COX-2 secondary pocket. The results of this study showed that the type of substituent on the N-3 hydantoin ring substituent is important for COX-2 inhibitory activity. Full article

The objective of the present investigation was to enhance the oral bioavailability of practically insoluble Candesartan cilexetil [CC] by preparing nanosuspension. The nanosuspension was prepared by media milling using zirconium oxide beads and converted to solid state by spray drying. The spray dried nanosuspension of CC [SDCN] was evaluated for particle size, zeta potential, saturation solubility, crystallanity, surface morphology and dissolution behavior. SDCN showed particle size of 223.5±5.4 nm and zeta potential of −32.2±0.6 mV while saturation solubility of bulk CC and SDCN were 125±6.9 μg/ml and 2805±29.5 μg/ml respectively, showing more than 20 times increase in solubility. Differential Scanning Calorimetry [DSC] and X-ray diffraction [XRD] analysis showed that crystalline state of CC remained unchanged in SDCN. Dissolution studies in phosphate buffer pH 6.5 containing 0.7% Tween 20 showed that 53±5% of bulk drug dissolved in 15 min whereas SDCN was almost completely dissolved exhibiting higher dissolution velocity and solubility. Transmission electron microscopy [TEM] revealed that nanocrystals were not of uniform size, and approximately of oval shape. Pharmacodynamic study based on deoxycorticosterone acetate [DOCA] salt model was performed in rats to evaluate in-vivo performance, which showed 26.75±0.33% decrease in systolic blood pressure for nanosuspension while plain drug suspension showed 16.0±0.38% reduction, indicating that increase in dissolution velocity and saturation solubility leads to enhancement of bioavailability of SDCN when compared to bulk CC suspension. Thus, the results conclusively demonstrated a significant enhancement in antihypertensive activity of candesartan when formulated as nanosuspension. Full article

Pathological changes in an organ or tissue may be reflected in proteomic patterns in serum. The early detection of cancer is crucial for successful treatment. Some cancers affect the concentration of certain molecules in the blood, which allows early diagnosis by analyzing the blood mass spectrum. It is possible that exclusive serum proteomic patterns could be used to differentiate cancer samples from non-cancer ones. Several techniques have been developed for the analysis of mass-spectrum curve, and use them for the detection of prostate, ovarian, breast, bladder, pancreatic, kidney, liver, and colon cancers. In present study, we applied data mining to the diagnosis of ovarian cancer and identified the most informative points of the mass-spectrum curve, then used student t-test and neural networks to determine the differences between the curves of cancer patients and healthy people. Two serum SELDI MS data sets were used in this research to identify serum proteomic patterns that distinguish the serum of ovarian cancer cases from non-cancer controls. Statistical testing and genetic algorithm-based methods are used for feature selection respectively. The results showed that (1) data mining techniques can be successfully applied to ovarian cancer detection with a reasonably high performance; (2) the discriminatory features (proteomic patterns) can be very different from one selection method to another. Full article

An ideal test used to characterize a product must be appropriate for the measurement of product quality, manufacturing consistency, product stability, and comparability studies. Flow cytometry has been successfully applied to the examination of antibodies and receptors on membrane surfaces; however, to date, the analytical validation of cytometry based assays is limited. Here we report on the validation of a flow cytometry-based assay used in the evaluation of nimotuzumab binding to cells over-expressing EGFR on cell surface. The assay was validated by examining, assay robustness, specificity, repeatability and intermediate precision. The assay was highly specific, robust for all studied factors except for cell fixation with 1% paraformaldehyde and met criteria for precision with RSD < 2%. In addition the assay has stability-indicating proper-ties evidenced by the ability to detect changes in mAb degraded samples. Most importantly, the assay demonstrated to be useful for its intended use. Full article

A series of chalcone-based diarylpyrazoles containing a phenylsulphone or carbonitrile moiety was synthesized. Thus, 3-acetylpyrazoles 6a–c and 10a–c were used as useful substrates in facile synthesis of functional pyrazoles 7a–f and 11a–f, respectively. The anti-inflammatory activity and ulcerogenic effect were evaluated and some of the obtained products possessed a significant anti-inflammatory activity. 1-[1-(3-Methylphenyl)-5-phenyl-4-(phenylsulfonyl)-1H-pyrazol-3-yl]ethanone (6b) showed a high activity when compared with indomethacin as reference drug with lower gastrointestinal (GI) profile. Furthermore, molecular docking studies were performed in order to rationalize the obtained biological results. Full article

Considering the significance of progesterone receptor (PR) modulators, the present study is explored to envisage the biophoric signals for binding to selective PR subtype-A using ligand-based quantitative structure activity relationship (QSAR) and pharmacophore space modeling studies on nonsteroidal substituted quinoline and cyclocymopol monomethyl ether derivatives. Consensus QSAR models (Training set (Tr): n_Tr=100, R²_pred=0.702; test set (Ts): n_Ts=30, R²_pred=0.705, R²_m=0.635; validation set (Vs): n_Vs=40, R²_pred=0.715, R²_m=0.680) suggest that molecular topology, atomic polarizability and electronegativity, atomic mass and van der Waals volume of the ligands have influence on the presence of functional atoms (F, Cl, N and O) and consequently contribute significant relations on ligand binding affinity. Receptor independent space modeling study (Tr: n_Tr=26, Q²=0.927; Ts: n_Ts=60, R²_pred=0.613, R²_m=0.545; Vs: n_Vs=84, R²_pred=0.611, R²_m=0.507) indicates the importance of aromatic ring, hydrogen bond donor, molecular hydrophobicity and steric influence for receptor binding. The structure-function characterization is adjudged with the receptor-based docking study, explaining the significance of the mapped molecular attributes for ligand-receptor interaction in the catalytic cleft of PR-A. Full article

A HPLC method has been described for simultaneous determination of Losartan potassium and Metolazone in formulation. This method is based on a HPLC separation of the two drugs on the Thermo Hypersil BDS–C₁₈ (250 mm × 4.6 mm, 5.0 μm) with isocratic conditions and a simple mobile phase containing acetonitrile:water (60:40) at a flow rate of 0.8 mL/min using UV detection at 237 nm. This method has been applied to a marketed formulation without interference of excipients. The linear regression analysis data for the calibration plots showed a good linear relationship over the concentration range of 2–12 μg/mL for Losartan potassium and 0.2–1.2 μg/mL for Metolazone, respectively. The method was validated for precision, robustness and recovery. Statistical analysis showed that the method is repeatable and selective for the estimation of Losartan potassium and Metolazone. Full article

Glucagon-like peptide-1 (GLP-1) is an intestinal hormone with well-established glucose-lowering activity. The in vitro and in vivo actions of natural putative secretagogues of GLP-1 were investigated. The acute GLP-1 releasing activity of olive leaf extract (OLE), glutamine (GLN), alpha casein (ACAS), beta casein (BCAS) and chlorogenic acid (CGA) were assessed in STC-1 cells and C57BL/6 mice. All compounds except ACAS significantly increased acute in vitro GLP-1 secretion (66-386%; P<0.05–0.001). Oral gavage of OLE and GLN modestly increased plasma GLP-1 concentrations (48% and 41%, respectively), but did not lower glycaemic excursions. OLE and GLN are potent stimulators of GLP-1 secretion both in vitro and in vivo and chronic studies should assess their suitability as nutritional therapies for type 2 diabetes. Full article

Type 2 diabetes mellitus is associated with dyslipdemia, insulin resistance and non alcoholic fatty liver disease. The purpose of the current study was to assess whether type 2 diabetes mellitus-induced hyperglycemia has an effect on the lipid profile and release of oxidative stress markers and inflammatory mediators in patients with non alcoholic fatty liver disease and normal liver function tests which may in turn lead to enhancing the pathogenicity of this liver disease. For this purpose, one hundred and five outpatients, matched in age and weight, were classified into two groups: the first group consisted of patients with non alcoholic fatty liver disease and the second group consisted of patients with non alcoholic fatty liver disease in conjunction with hyperglycemia due to the presence of type 2 diabetes mellitus. In all patients, lipid profile, oxidative stress, and inflammatory mediators were assessed by measuring serum concentrations of triglycerides, low density lipoprotein, hydrogen preroxide, malondialdehyde, tumor necrosis factor-alpha and interleukin-6, respectively. In the studied population, it was found that the presence of type 2 diabetes mellitus-induced hyperglycemia significantly impaired lipid profile, and significantly enhanced the formation of hydrogen preroxide and malon-dialdehyde as well as significantly increased the release of tumor necrosis factor-alpha and interleukin-6 in the second group of patients. In addition, plasma glucose level showed significant positive correlation with hydrogen peroxide, malondialdehyde, tumor necrosis factor-alpha and interleukin-6. From the previous results, it was concluded that the presence of type 2 diabetes mellitus-induced hyperglycemia results in significant increase in lipid profile, oxidative stress markers and inflammatory mediators in patients with non alcoholic fatty liver disease and normal liver function tests. For this reason, further research studies may be essential to evaluate the benefit of adding suitable antioxidant and anti-inflammatory drugs to the treatment regimen for this group of patients. In addition, regular monitoring of blood glucose levels and liver function tests should be advised to this category of patients to reduce liver fat deposition and avoid the development of non alcoholic steatohepatitis, cirrhosis or liver cancer and their related complications. Full article

A stability indicating reversed phase ultra performance liquid chromatography (RP-UPLC) method was developed for simultaneous determination of ambroxol hydrochloride (AMB), cetirizine hydrochloride (CTZ), methylparaben (MP) and propylparaben (PP) in liquid pharmaceutical formulation. The desired chromato-graphic separation was achieved on an Agilent Eclipse plus C18, 1.8 μm (50 x 2.1 mm) column using gradient elution at 237 nm detector wavelength. The optimized mobile phase consists of a mixture of 0.01 M phosphate buffer and 0.1 % triethylamine as a solvent-A and acetonitrile as a solvent-B. The developed method separates AMB, CTZ, MP and PP in presence of twelve known impurities/degradation products and one unknown degradation product within 3.5 min. Stability indicating capability was established by forced degradation experiments and seperation of known and unknown degradation products. The lower limit of quantification was established for AMB, CTZ, MP and PP. The developed RP-UPLC method was validated according to the International Conference on Harmonization (ICH) guidelines. This validated method is applied for simultaneous estimation of AMB, CTZ, MP and PP in commercially available syrup samples. Further, the method can be extended for estimation of AMB, CTZ, MP, PP and levo-cetirizine (LCTZ) in various commercially available dosage forms. Full article

The present study has been undertaken to apply the concept of nanoparticulate mucopenetrating drug delivery system for complete eradication of Helicobacter pylori (H. pylori), colonised deep into the gastric mucosal lining. Most of the existing drug delivery systems have failed on account of either improper mucoadhesion or mucopenetration and no dosage form with dual activity of adhesion and penetration has been designed till date for treating H. pylori induced disorders. In the present study, novel chitosan-alginate polyelectrolyte complex (CS-ALG PEC) nanoparticles of amoxicillin have been designed and optimized for various variables such as pH and mixing ratio of polymers, concentrations of polymers, drug and surfactant, using 3³ Box-Behnken design. Various studies like particle size, surface charge, percent drug entrapment, in-vitro mucoadhesion and in-vivo mucopenetration of nanoparticles on rat models were conducted. The optimised FITC labelled CS-ALG PEC nanoparticles have shown comparative low in-vitro mucoadhesion with respect to plain chitosan nanoparticles, but excellent mucopenetration and localization as observed with increased fluorescence in gastric mucosa continuously over 6 hours, which clinically can help in eradication of H. pylori. Full article

Human African Trypanosomiasis (HAT) also called sleeping sickness is caused by subspecies of the parasitic hemoflagellate Trypanosoma brucei that mostly occurs in sub-Saharan Africa. The current chemotherapy of the human trypanosomiases relies on only six drugs, five of which have been developed more than 30 years ago, have undesirable toxic side effects and most of them show drug-resistance. Though development of new anti-trypanosomal drugs seems to be a priority area research in this area has lagged far behind. The given review mainly focus upon the recent synthetic and computer based approaches made by various research groups for the development of newer anti-trypanosomal analogues which may have improved efficacy and oral bioavailability than the present ones. The given paper also attempts to investigate the relationship between the various physiochemical parameters and anti-trypanosomal activity that may be helpful in development of potent anti-trypanosomal agents against sleeping sickness. Full article

Two unknown impurities were detected in verapamil hydrochloride bulk drug using isocratic reversed-phase high performance liquid chromatography (HPLC). These impurities were isolated by preparative HPLC. Spectral data for the isolated impurities were collected. Based on the spectral data derived from two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy and mass spectrometry (MS), impurity-1 and impurity-2 were characterized as 2-(3,4-dimethoxyphenyl)-3-methylbut-2-enenitrile and 2-(3,4-dimethoxyphenyl)-2-isopropyl-3-methylbutanenitrile, respectively. Full article

A series of 2,5,7-trisubstituted pyrimido[4,5-d]pyrimidine cyclin-dependent kinase (CDK2) inhibitors is designed and synthesized. 6-Amino-2-thiouracil is reacted with an aldehyde and thiourea to prepare the pyrimido[4,5-d]-pyrimidines. Alkylation and amination of the latter ones give different amino derivatives. These compounds show potent and selective CDK inhibitory activities and inhibit in vitro cellular proliferation in cultured human tumor cells. Full article