Quantification of toxic heavy metals, trace elements and essential minerals contents in traditional herbal medicines commonly utilized in Khyber Pakhtunkhwa, Pakistan.

Traditional herbal medicines and health supplements have been empirically used to treat various disorders but most of them are not standardized and have not been experimentally validated for safety and efficacy. In the present study, various dosage forms of traditional herbal medicines prescribed for specific diseases were collected from local practitioners at different districts of Khyber Pakhtunkhwa, Pakistan. The collected samples were analyzed for heavy metal, trace elements, and minerals using atomic absorption spectroscopy. All the tested samples contained heavy metals, trace elements and minerals in different concentrations. All the samples were tested positive for the presence of toxic heavy metals such as arsenic (As), cadmium (Cd) and lead (Pb). The trace elements like cobalt (Co), iron (Fe), zinc (Zn) and chromium (Cr) were also detected in acceptable range. Similarly, the samples analyzed were rich in some of the essential minerals such as sodium (Na), magnesium (Mg) and calcium (Ca) which are necessary for the proper functioning of the body. The hazard quotient (HQ) values were measured for toxic heavy metals to determine their safe ranges for human body. The HQ values were above the permissible range for arsenic (As) in all detected samples while for cadmium (Cd) and lead (Pb), the values ware above in 50 % of the analyzed samples. The detection of toxic metals and their HQ values beyond the permissible limits in different dosage forms raised questions about their quality. This study suggests that evaluation of traditional herbal remedies for the metals contents and their standardization are strongly recommended for quality assurance and protection of public health.

Formulation Development and Characterization of pH Responsive Polymeric Nano-Pharmaceuticals for Targeted Delivery of Anti-Cancer Drug (Methotrexate).

Oral administration of pH sensitive/stimuli responsive nanoparticles are gaining importance because of the limited side effects, minimum dose and controlled drug release. The objective of this study was to develop and evaluate pH sensitive polymeric nanoparticles for methotrexate with the aim to maximize the drug release at target site. In the presented study, pH sensitive polymeric nanoparticles of methotrexate were developed through modified solvent evaporation technique using polymer Eudragit S100. Different process parameters like drug to polymer ratio, speed of sonication, concentration of surfactant and time of sonication were optimized by evaluating their effects on particle size, PDI, zeta potential, entrapment/encapsulation efficiency. The developed formulations were evaluated for their size, polydispersity (PDI), zeta potential, encapsulation efficiency, XRD, scanning electron microscopy, in-vitro drug release and stability studies. Best results were obtained with poloxamer-407 and PVA and were selected as surfactants. Physicochemical characterization of the developed formulations showed that the particle size lies in the range 165.7 ± 1.85-330.4 ± 4.19, PDI 0.119 ± 0.02-0.235 ± 0.008, zeta potential -0.163 ± 0.11--5.64 ± 0.36 mV, and encapsulation efficiency more than 61%. The results of scanning electron microscopy revealed that nanoparticles have regular geometry with spherical shape. Initially the drug release occur through diffusion followed by erosion. The present studies showed that MTX-ES100 nanoparticles prepared during this study have the desired physicochemical properties, surface morphology and release characteristics used to target the desired organs.

Rosuvastatin pharmacokinetics in Pakistani healthy volunteers in comparison with other population.

In current study, the pharmacokinetics (PK) of rosuvastatin were evaluated in Pakistani healthy volunteers and compared with those reported in other population. This was a randomized and open labeled clinical trial in which a single oral dose of 40 mg rosuvastatin was administered to the overnight fasted healthy volunteers. Plasma concentrations of rosuvastatin were quantified by a validated liquid chromatography-tandem mass spectrometry method. The PK parameters of rosuvastatin and its metabolite N-desmethyl-rosuvastatin were determined by PK specific software i.e., PK-Summit® (PK-Solutions). A total of 20 healthy volunteers having BMI in the normal ranges were included in this study. All PK parameters were represented as mean ± SD and 95% confidence intervals of the means have been calculated. The Cmax (29.07 ± 6.88 ng/mL), [AUC]xo (206.65 ± 55.27 ng/hr/mL) and CL/F (3275.26 ± 1072.87 mL/hr) were slightly higher in our study, whereas the values of Vd (19377.23 ± 9114.29 mL) and tmax (3.0 ± 0.46 hr) were comparatively smaller. Overall, the PK parameters of rosuvastatin determined in our study were in compliance with other reported. Therefore, no adjustments in the dosing schedule or dose are warranted.

Comparative pharmacokinetics of Omeprazole and its metabolites in poor and extensive metabolizer Pakistani healthy volunteers and a review of different studies.

This study was designed to evaluate a comparative single dose (40mg) pharmacokinetics (PK) of Omeprazole (OMP) and its two metabolites, 5-hydroxy Omeprazole (5-OH-OMP) and Omeprazole sulphone (OMP-S) in poor (PM) and extensive (EM) metabolizer Pakistani healthy adult volunteers. The frequency of CYP2C19 and CYP3A4 varies widely in different populations. The present study was conducted to evaluate the PK of OMP and its two metabolites in Pakistani population and to review different studies conducted after administration of single dose of OMP. Twenty two subjects were enrolled in this study and divided into two groups. The CYP2C19 phenotyping was evaluated by the metabolic ratio of OMP to 5-OH-OMP. It was a single dose, open label study and the blood samples from subjects were collected at different time intervals until 24 hours. The PK parameters were calculated using the PK-summit software. The metabolic ratio of area under the plasma concentration-time curve AUCOMP/5-OH-OMP was 1.86 ± 0.572 and13.84 ± 2.504 for EM and PM, respectively; maximum plasma concentration (Cmax) of OMP was increased by two folds for PM while the AUC∞ was increased by 3 folds; the Cmax and AUC∞ of 5-OH-OMP decreased for PM by 2 folds while there was 3 fold increase observed in the Cmax and AUC∞ of OMP-S. The PK of OMP and its metabolites in different populations were also discussed, and issues regarding CYP2C19 and CYP3A4 genotyping were also extensively reviewed. In EM of CYP2C19 the concentration of 5-OH-OMP is higher while that of OMP-S is lower. This study as well as reported studies reveals that in PM of CYP2C19 more drugs are available for CYP3A4 to be metabolized. A correlation between CYP2C19 EM and PM activity with CYP3A4 needs to be established.

Effect of clopidogrel on the hydroxylation and sulfoxidation of omeprazole: A single dose study in healthy human volunteers.

Based upon the known potential interaction between omeprazole (OMP) and clopidogrel (CLOP), the current study was designed to evaluate the effect of CLOP on disposition of OMP and its two major metabolites, 5-hydroxyomeprazole (5-OH-OMP) and omeprazole sulfone (OMP-S) in healthy clinical subjects. A randomized, open label, 2-period, crossover study was designed. Twelve volunteers were selected, of whom eight were extensive metabolizers (EM) of CYP2C19 and 4 were poor metabolizers (PM). They received single dose of OMP either alone or in combination with CLOP (single dose) and samples were collected periodically to calculate various pharmacokinetic parameters. Changes in most of the pharmacokinetic parameters of OMP, 5-OH-OMP and OMP-S were insignificant (P ˃ 0.05) both in EM and PM except for the maximum concentration (Cmax) of 5-OH-OMP and OMP-S in EM. The OMP Cmax and AUC0-∞ was increased both in EM and PM after concomitant administration of OMP with CLOP. The 5-OH-OMP Cmax was decreased in both EM and PM, demonstrating that CLOP inhibits hydroxylation of OMP. The OMP-S Cmax and AUC0-∞ were increased both in EM and PM showing that CLOP may induce sulfoxidation of OMP. It was concluded that CLOP may inhibit hydroxylation of OMP to a greater extent in EM than in PM, leading to higher OMP Cmax and AUC0-∞. Furthermore, the sulfoxidation of OMP may also be induced by CLOP. So, it is suggested that both these drugs should be carefully prescribed together to avoid any harm to the patients. (Application number13/EC/Pharm. Ref number 12/Pharm).

A simple, rapid and sensitive RP-HPLC-UV method for the simultaneous determination of sorafenib & paclitaxel in plasma and pharmaceutical dosage forms: Application to pharmacokinetic study.

A simple, economical, fast, and sensitive RP-HPLC-UV method has been developed for the simultaneous quantification of Sorafenib and paclitaxel in biological samples and formulations using piroxicam as an internal standard. The experimental conditions were optimized and method was validated according to the standard guidelines. The separation of both the analytes and internal standard was achieved on Discovery HS C18 column (250mm×4.6mm, 5µm) using Acetonitrile and TFA (0.025%) in the ratio of (65:35V/V) as the mobile phase in isocratic mode at a flow rate of 1ml/min, with a wavelength of 245nm and at a column oven temperature of 25°Cin a short run time of 12min. The limits of detection (LLOD) were 5 and 10ng/ml while the limits of quantification (LLOQ) were 10 and 15ng/ml for sorafenib and paclitaxel, respectively. Sorafenib, paclitaxel and piroxicam (IS) were extracted from biological samples by applying acetonitrile as a precipitating and extraction solvent. The method is linear in the range of 15-20,000ng/ml for paclitaxel and 10-5000ng/ml for sorafenib, respectively. The method is sensitive and reliable by considering both of its intra-day and inter-day co-efficient of variance. The method was successfully applied for the quantification of the above mentioned drugs in plasma. The developed method will be applied towards sorafenib and paclitaxel pharmacokinetics studies in animal models.

Variation in pharmacokinetics of omeprazole and its metabolites by gender and CYP2C19 genotype in Pakistani male and female subjects.

Pharmacokinetics (PK) variation of drugs in males and females may affect therapeutic effectiveness and safety. In current study the PK differences for omeprazole and its metabolites5-hydroxy-omeprazole and omeprazole-sulphone were evaluated in males and females. The current study also considered PK comparison of Pakistani subjects using the CYP2C19 genotype as variable. A single oral dose (40mg omeprazole), open-labeland, non-controlled clinical trial was arranged. Samples were quantified using reversed phase HPLC-UV method. CYP2C19 genotype of subjects was determined by tetra primer polymerization chain reaction (PCR) assay. There was a significant increase in Cmax (from 2 to 2.9µg/ml, p=0.004**), (from 6.67 to 8.74µg-hr/ml, p=0.05*) and elimination half-life (from 1.05 to 2.1 hr, p=0.0001*) of omeprazole in females compared with males. Cmax and of 5-hydroxy-omeprazole (0.0248* and 0.0001***, respectively) and omeprazole-sulphone (0.0001*** and 0.001**, respectively) was significantly higher in females than males when compared at 95% confidence interval. The Cmax and AUC of omeprazole showed a significant raise (p=0.01* and 0.04*, respectively) in Homz PMs (Homozygous Poor Metabolizers) compared with Homz EMs (Homozygous Extensive Metabolizers) and Htrz PMs (Heterozygous Poor Metabolizers) while Cmax and AUC of 5-hydroxy-omeprazolewas significantly higher (p=0.01* and 0.04*, respectively) in Homz EMs compared with Homz PMs and HtrzPMs. AUC of omeprazole was significantly higher in females while its elimination also took longer compared with males. AUC of omeprazole was significantly higher in Homz PMs indicating that CYP2C19* displayed genetically deficient metabolism in its homozygous state.

Simultaneous determination of domperidone and Itopride in pharmaceuticals and human plasma using RP-HPLC/UV detection: Method development, validation and application of the method in in-vivo evaluation of fast dispersible tablets.

Domperidone and Itopride are pro-kinetic agents, regulating the gastric motility and are commonly prescribed as anti emetic drugs. In the present study a simple, rapid and sensitive RP-HPLC/UV method was developed for simultaneous determination of Domperidone and Itopride in pharmaceutical samples and human plasma, using Tenofavir as internal standard. Experimental conditions were optimized and method was validated according to the standard guidelines. Combination of water (pH 3.0) and acetonitrile (65:35 v/v) was used as mobile phase, pumped at the flow rate of 1.5 ml/min. Detector wavelength was set at 210 nm and column oven temperature was 40oC. Unlike conventional liquid-liquid extraction, simple precipitation technique was applied for drug extraction from human plasma using acetonitrile for deprotienation. The method showed adequate separation of both the analytes and best resolution was achieved using Hypersil BDS C8 column (150 mm × 4.6 mm, 5 µm). The method was quite linear in the range of 20-600 ng/ml. Recovery of the method was 92.31% and 89.82% for Domperidone and Itopride, respectively. Retention time of both the analytes and internal standard was below 15 min. The lower limit of detection (LLOD) and lower limit of quantification (LLOQ) for Domperidone were 5 and 10 ng/ml while for Itopride was 12 and 15 ng/ml, respectively. The developed method was successfully applied for in-vivo analysis of fast dispersible tablets of Domperidone in healthy human volunteer. The proposed method was a part of formulation development study and was efficiently applied for determination of the two drugs in various pharmaceutical products and human plasma.

Effect of Omeprazole on the Pharmacokinetics of Rosuvastatin in Healthy Male Volunteers.

The current study aimed at the evaluation of, in vivo, the effect of omeprazole on the pharmacokinetics of rosuvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. Omeprazole is an acid suppressant and CYP2C9, CYP3A4, and CYP2C19 substrate and inhibitor, as well as inhibitor of transporters (like P-gp). This was a randomized, open-label, 2-period, crossover study. Healthy male volunteers (N = 20), divided into 2 groups, were given single oral doses of rosuvastatin 40 mg either alone (treatment period I) or concomitantly with omeprazole 40-mg capsule (treatment period II). Plasma concentrations of rosuvastatin (rosuva) and its metabolite N-desmethyl rosuvastatin (NDM-rosuva) were quantified by a validated liquid chromatography-tandem mass spectrometry method developed in our laboratory. An insignificant decrease (P > 0.05) has been observed in the values of maximum plasma concentrations, clearance, and half-life of rosuva, whereas an insignificant increase (P > 0.05) has been observed in the area under the plasma concentration-time curves from zero time to the last measurable concentration(Equation is included in full-text article.), that extrapolated to infinity (Equation is included in full-text article.), and mean residence time values after concomitant administration with omeprazole. Although omeprazole concomitant administration altered the pharmacokinetics of NDM-rosuva metabolite significantly, rosuva's very little metabolism (10%) suggests that these changes are of no clinical significance. Concomitant administration of omeprazole with rosuva did not alter the pharmacokinetics of rosuva in healthy volunteers. These data are consistent with other reported studies, indicating that rosuva is not a good candidate for metabolism-based drug-drug interactions. Therefore, rosuva can be administered safely along with omeprazole.

A PROSPECTIVE PHARMACOLOGICAL REVIEW OF MEDICINAL HERBS, CUCUMIS MELO AND BERBERIS VULGARIS, COMMONLY USED IN THE TREATMENT OF RENAL DISEASES IN PAKISTAN.

The kidneys are important organs which have many functions in the body, including the production of hormones, absorbtion of minerals and the filtration of blood, producing urine. Their failure can be fatal, therefore, to focus the study of such herbs which may be useful in treating renal disease is the need of hour. In Pakistan, Cucumis melo and Berberis vulgaris has been commonly used for renal problems. In both of these plants were found flavonoids, alkaloids and terpenes, which may stand for their renal protective properties. Their reported vitamin E contents and antioxidant potentials also provide a base for their defensive mechanism, may be due to their free radical scavenging properties. Further, their diuretic and urinary tract anti-ulcer properties also support their traditional use in renal diseases. Their anti-histaminic and anti-cholinergic properties also provide symptomatic treatment by decreasing prostaglandin level and due to antispasmodic properties. Concluding, both of these plants can be used for renal problems, especially Cucumis melo, which have both the nutritive and medicinal properties. Therefore, the renal disease patients are advised to take much of this particular fruit, especially their seeds to make their kidneys healthy.

Enhancement of dissolution rate of class II drugs (Hydrochlorothiazide); a comparative study of the two novel approaches; solid dispersion and liqui-solid techniques.

Liqui-solid technique and solid dispersion formation are two novel approaches for enhancement of dissolution rate of BCS class II drugs. Liqui-solid compact converts a liquid drug or drug solution into a free flowing powder with enhanced dissolution rate. In case of solid dispersion drug is molecularly dispersed in a hydrophilic polymer in solid state. In the present study, Liqui-solid and solid dispersion techniques were applied to enhance the dissolution of the Hydrochlorothiazide. Three formulations of Hydrochlorothiazide were prepared by liqui-solid technique using micro crystalline cellulose as carrier material and colloidal silicon dioxide as coating material. Water, poly ethylene glycol-400 and Tween-60 were used as solvent system. Solid dispersions of Hydrochlorothiazide were prepared by solvent fusion method using PEG-4000 as carrier polymer. Tablets were subjected to evaluation of various physical and chemical characteristics. Dissolution profiles of tablets prepared by the novel techniques were compared with marketed conventional tablets. Model independent techniques including similarity factor, dissimilarity factor and dissolution efficiency were applied for comparison of dissolution profiles. The results obtained indicated that liqui-solid compact formulations were more effective in enhancing the dissolution rate compared with solid dispersion technique. The liqui-solid compacts improved the dissolution rate up to 95% while the solid dispersion increased it to 88%.

Report: Antibacterial and antifungal activities of leaf extract of Achyranthes aspera (Amaranthaceae) from Pakistan.

Alcoholic extract and various fractions of Achyranthes aspera leaves, traditionally used in Pakistan for treatment of infectious diseases was screened for in vitro antibacterial and antifungal activity. The chloroform and butanol fractions were found to be the most active among the fractions, showing considerable antibacterial activity against Shigella flexneri and Escherichia coli. The highest activity was found in the ethylacetate fraction (17 mm zone of inhibition) against gram-negative (Salmonella typhi) bacteria, with MIC value as 0.29 mg/mL. In antifungal screening, moderate activity was shown by the chloroform fraction (50 % inhibition) against Microsporum canis, with MIC value as 0.25mg/mL. Considerable level of antifungal activity was depicted by crude extract, hexane and butanol fractions against Aspergillus flavus and Microsporum canis. The ability of various extracts of Achyranthes aspera to inhibit different strains of fungi and bacteria indicates its potential use for the treatment of microbial infections.

Pharmacokinetics of omeprazole and its metabolites in three phases of menstrual cycle.

Omeprazole (OMP) is effective in the treatment of gastric hyperacidity and is metabolized by CYP2C19 and CYP3A4. These enzymes are modulated by estrogen and progesterone which regulate the menstrual cycle. The variations in the pharmacokinetics (PK) of many drugs like amphetamine, benzodiazepines and caffeine have been reported during menstrual cycle. In present study, the PK of the omeprazole and its metabolites was investigated during various phases of the menstrual cycle. A single oral dose, open-label, non-controlled, pharmacokinetic study of omeprazole was conducted in healthy young/premenopausal females (n = 16). The PK of omeprazole, 5-hydroxy-omeprazole and omeprazole sulphone was evaluated in three phases of menstrual cycle. The blood samples were analyzed using reversed-phase HPLC coupled with UV detector and the PK data were evaluated. The activities of CYP2C19 and CYP3A4 were determined as AUC(OH-OMP)/AUC(OMP) and AUC(OMP-SUL)/AUC(OMP), respectively. Omeprazole showed significantly (p < 0.05) higher [Formula: see text] and CL/F in follicular and menstrual phases, respectively. The [Formula: see text] of 5-hydroxy omeprazole was also significantly (p < 0.05) higher in follicular phase. The metabolic ratios (MR) of 5-hydroxy omeprazole and omeprazole sulphone were lower in follicular phase compared with the luteal phase. The present study suggests that high estrogen levels of follicular phase may result in increased absorption of omeprazole. The lower MR for 5-hydroxy omeprazole and omeprazole sulphone in follicular phase as compared to luteal phase suggests that metabolism of omeprazole is low in follicular phase as compared to luteal phase, which is progesterone-dominant phase. However, the clinical significance for these findings needs to be determined.

Pharmacokinetic study of rosuvastatin in males and females.

Rosuvastatin is used to treat dyslipidemia and is metabolized by CYP2C9 that shows variable metabolic activity in males and females. Pharmacokinetics (PK) of drugs varies in males and females that may result in altered drug response and therapeutic efficacy. In current study, PK of rosuvastatin has been evaluated in males and females. A single oral dose (40 mg rosuvastatin), open-label and non-controlled PK study was arranged. A reversed phase HPLC method was applied for quantification of rosuvastatin in serum samples. PK parameters of rosuvastatin were compared in males and females by applying student t test at 95 % confidence interval. The C max, [Formula: see text]and [Formula: see text]of rosuvastatin was significantly higher (p < 0.05) in females compared with males. The Vd/F of rosuvastatin was insignificantly higher (p > 0.05) in males compared with females while CL/F was significantly (p < 0.05) faster in males when compared at 95 % confidence interval. Rosuvastatin plasma level was significantly high in females compared with males that may be a possible reason for higher incidence of cardiac myopathy and other side effects in females. The variation in PK of drugs in males and females may require dose adjustment for maximum therapeutic effectiveness and safety.

Evaluation of anti-inflammatory activity of selected medicinal plants of Khyber Pakhtunkhwa, Pakistan.

In present study, the anti-inflammatory potential of three medicinal plants, Xanthium strumarium, Achyranthes aspera and Duchesnea indica were evaluated, using both in vitro and in vivo assays. Carrageenan induced hind paw edema model was used to carry out the in vivo anti-inflammatory activity, while for in vitro screening lipoxygenase inhibition assay was used. Crude extract of all the selected plants depicted significant (plt;0.001) anti-inflammatory activity, at late phase of inflammation. Achyranthes aspera also showed considerable anti-inflammatory activity (47%) at relatively lower concentration (200 mg/ml), at the initial phase of inflammation. Similarly the ethyl acetate fraction of all the selected plants showed significant lipoxygenase inhibition activity when compared with the standard drug (Baicalein). The results obtained from both in vitro and in vivo anti-inflammatory activity suggest that the ethyl acetate fraction of the crude extract of all the selected plants can be used for the isolation of new lead compounds with better anti-inflammatory activity.

Development of a method to measure free and bound ropivacaine in human plasma using equilibrium dialysis and hydrophilic interaction chromatography coupled to high resolution mass spectrometry.

The pharmacodynamics of absorption of local anaesthetics used during surgical procedures into tissues is governed by the amount of free drug in plasma. Toxicity may occur during continuous infusions if the levels of free drug become too high which may occur if the binding capacity of the α-1-acid glycoprotein present in plasma is exceeded. In order to monitor this a method was developed for the determination of the amount of free and bound ropivacaine in human plasma during knee and hip surgery. Rapid equilibrium dialysis units were used to separate free and bound drug then protein and buffer salts were removed by solvent precipitation. Analysis was carried out using a ZICHILIC HPLC column interfaced with an LTQ Orbitrap mass spectrometer. The following extracted ion ranges ([M+H](+)) were monitored: m/z 275.21-275.22 for ropivacaine and m/z 235.175-235.185 for lidocaine. The method was calibrated by spiking ropivacaine, and a fixed amount of lidocaine as internal standard, into plasma over the range 0.01-1.5 µg/ml. The equation of the line was y=0.886x±4.2% (n=2), forcing the curve through zero since blank plasma was free of the analyte. The values obtained for the accuracy and precision of the analysis of plasma spiked at 0.03 µg/ml and 1.5 µg/ml were 93.2%±2.8% and 95.4%±1.5% respectively (n=5). Repeat analysis of a patient sample for free and bound drug gave the following values for levels of ropivacaine: bound 1.63 µg/ml±1.48%, unbound 0.0671 µg/ml±1.68% (n=5).

Evaluation of biological, physical and chemical properties of mineral trioxide aggregate mixed with 4-META/MMA-TBB.

AIM: To evaluate the change in physical, chemical and biological properties when mineral trioxide aggregate (MTA) is mixed with a resin 4-methacryloxyethyl trimellitate anhydride (4-META)/methyl methacrylate-tri-n-butyl-borane (MMA)-TBB. MATERIALS AND METHODS: For biological evaluation MTA was inoculated in Wistar rat's subcutaneous tissue and peripheral tissue response was checked after 72 h, 7 days, 15 days and 30 days. Setting time was evaluated using Gillmore needle. The Ca++ release at the end of 24 h was checked using ethylenediaminetetraacetic acid titration method. For all the trials MTA mixed with water was kept as a control and the ratio of MTA with resin was 1:1 by weight. RESULTS: The biological reaction was verified by two observers and their readings were matched using kappa test and there was an excellent relevance. There was no significant difference in the tissue reaction at the end of 30 days where both the groups seemed to show healing. Setting time of MTA with 4-META/MMA-TBB was coming to a mean of 26 min (approx.), which is almost 6 times lesser than that of MTA with water. After applying t test, the difference in Ca++ release was found significant (P = 0.00), with mean of 0.044 and 0.031 mol/L of MTA with water and MTA with 4-META/MMA-TBB respectively. CONCLUSION: Under the parameters of this study, this new experimental cement has better handling, physical and chemical properties. Even its subcutaneous tissue reaction is comparable to MTA mixed with water.

Development and evaluation of diclofenac sodium thermorevesible subcutaneous drug delivery system.

The objective of current work was to develop and evaluate thermoreversible subcutaneous drug delivery system for diclofenac sodium. The poloxamer 407, methyl cellulose, hydroxypropyl methyl cellulose and polyethylene glycol were used alone and in combination in different ratios to design the delivery system. The physical properties like Tsol-gel, viscosity, clarity of solution and gel were evaluated. The in vitro release of the drug delivery system was evaluated using membrane less method and the drug release kinetics and mechanism was predicted by applying various mathematical models to the in vitro dissolution data. Rabbits were used as in vivo model following subcutaneous injection to predict various pharmacokinetics parameters by applying Pk-Summit software. The in vitro and in vivo data revealed that the system consisting of the poloxamer 407 in concentration of 20% (DP20) was the most capable formulation for extending the drug release and maintaining therapeutic blood level of DS for longer duration (144 h). The data obtained for drug content after autoclaving the solutions indicate that autoclaving results in 6% degradation of DS. The data also suggested that the studied polymers poloxamer, MC and PG are good candidate to extend the drug release possessing a unique thermoreversible property.

Simultaneous determination of timolol maleate, rosuvastatin calcium and diclofenac sodium in pharmaceuticals and physiological fluids using HPLC-UV.

A novel HPLC-UV method was developed for the simultaneous determination of timolol (TM), rosuvastatin (RST), and diclofenac sodium (DS) in pharmaceuticals, human plasma and aqueous humor using naproxen sodium as internal standard (IS). The target compounds were analyzed on Hypersil BDS C(18) column (250 mm × 4.6 mm, 5 µm), applying 0.2% triethylamine (TEA) and acetonitrile (ACN) (40:60, v/v), in isocratic mode as mobile phase, pH 2.75 adjusted with 85% phosphoric acid at a flow rate of 1 ml/min. The column oven temperature was kept at 45°C and the peak response was monitored at 284 nm after injecting a 50 µl sample into HPLC system. The direct liquid-liquid extraction procedure was applied to human plasma and bovine aqueous humor samples using mobile phase as an extraction solvent after deproteination with methanol. The different HPLC experimental parameters were optimized and the method was validated according to standard guidelines. The recoveries of the suggested method in human plasma were 98.72, 96.04, and 95.14%, for TM, RST, and DS, while in aqueous humor were 94.99, and 98.23%, for TM, and DS, respectively. The LOD values were found to be 0.800, 0.500, and 0.250 ng/ml, for TM, RST, and DS, respectively, while their respective LOQ values were 2.00, 1.50, and 1.00 ng/ml. The co-efficient of variation (CV) were in the range of 0.1492-1.1729% and 1.0516-4.0104%, for intra-day and inter-day studies, respectively. The method was found accurate in human plasma and bovine aqueous humor and will be applied for the quantification of these compounds in plasma, and aqueous humor samples using animal models and in pharmaceuticals.