Effect of polymeric stabilizers on the size and stability of PLGA paclitaxel nanoparticles.

The aim of this study is to formulate polymeric paclitaxel nanoparticles with various stabilizers to improve solubility, enhance stability, maximize therapeutic efficacy and minimize detrimental toxicities of paclitaxel. In this study, trastuzumab-guided poly lactic-co-glycolic acid (PLGA)-loaded paclitaxel nanoparticles were formulated with pluronic F-127, polyvinyl alcohol (PVA), poloxamer 407, Tween-80, span 20, sodium dodecyl sulfate (SDS), and sodium lauryl sulfate (SLS) at different concentrations (0.5, 1, 1.5 and 2%) using the solvent evaporation method. The nanoparticles were evaluated for physicochemical characteristics and short and long-term stability. The optimum particle size (190 nm ± 12.42 to 350 nm ± 11.1), PDI (0.13 ± 0.02 to 0.2 ± 0.01), surface charge (-19.1mv ± 1.5 to -40.4mv ± 1.6), drug loading (2.43 to 9.5 %) and encapsulation efficiency (greater than 80 %) were obtained with these stabilizers while keeping the polymer concentration, temperature, probe size, amplitude and sonication time constant. The nanoformulations were stably stored at 4 °C. The nanoformulations of paclitaxel with pluronic F-127, polyvinyl alcohol (PVA), and poloxamer 407 were found to be more soluble, stable, uniform in physicochemical properties, and efficient in drug loading and encapsulation for improved therapeutic effects.

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.

A clinical study showing altered antioxidants profile in patients with hypertension.

We compared the plasma antioxidants level of normal control group with that of hypertensive patients in order to test the hypothesis "that antioxidants level has been diminished in hypertensive patients and that antioxidants are interconnected with each other making a network. The plasma and red blood cells antioxidants level of newly diagnosed hypertensive patients [(n=30), (mean age 53 years), (mean systolic BP 158 mmHg, mean diastolic BP 100 mmHg)] were compared to those of the control subjects [(n=30), (mean age 50 years), (mean systolic BP 126 mmHg, mean diastolic BP 90 mmHg)] using liquid chromatography linked with electrochemical detector (HPLC-ECD). The data was analyzed by Minitab software at a 95% confidence interval (p<0.05) as significant. The comparison between the two groups was made applying 2-sample and paired t-test. The individual concentration of antioxidants in both plasma and red blood cells of hypertensive patients was lower in comparison with that of control group while the oxidized/reduced ratios of these antioxidants were higher in hypertensive patients in comparison with that of control group. It is concluded that antioxidants level had been diminished in the hypertensive patients when compared with control group. The overall concentration of all antioxidants has been diminished in the oxidative stress induced pathological conditions which confirm that the studied antioxidants are working in a network. This study may be helpful for the recommendation of antioxidants intervention.

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.

Nephroprotective property of Cinnamomum zeylanicum and its antibacterial activity in combination with gantamicin.

Cinnamomum zeylanicum has strong antioxidant properties and has been presented to have nephroprotective effects. Present work was aimed to study the nephroprotective property of the plant extract through urinary enzymes excretion, to confirm its protective effects and to observe the antibacterial activities of gentamicin in combination with the plant extract. 200mg/kg/day of the plant extracts were administered alone and as co-therapy with gentamicin. Urinary lactate dehydrogenase (LDH) and Urinary alkaline phospatase (ALP) excretions were observed through reagents kits with the help of Power-Lab 300. Antibacterial activities were assessed for gentamicin alone and in combination with the extract. Present study showed that the plant extract have excess quantity of flavonoids, which may responsible for attenuating the excessive excretion of urinary LDH. However, Urinary ALP excretion was found remained same throughout the study period in all experimental groups; might be detected in acute damage. Further, the plant also proved to have no decreasing impact on the antibacterial activities of gentamicin.

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.

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.

Development and evaluation of pluronic- and methylcellulose-based thermoreversible drug delivery system for insulin.

The objective of the current work was to develop and evaluate thermoreversible subcutaneous drug delivery system for Insulin. Thermoreversible in-situ gel system was developed and evaluated both in-vitro and in-vivo comprising of pluronic F-127 alone or in combination with methylcellulose in different ratios. The drug release kinetics and mechanism was predicted by applying various mathematical models to the in-vitro dissolution data. Rabbits were used as animal model following subcutaneous injection to predict various pharmacokinetic parameters by applying Pk-Summit® software. The in-vitro and in-vivo data revealed that the formulation IPM 15/3 consisting of the pluronic F-127 (15% w/v) and methylcellulose (3% w/v) was the most robust and capable formulation for extending the drug release and maintaining basal plasma insulin level between 10 and 40 µU/ml for 240 h (10 d).

Application of SeDeM Expert system in formulation development of effervescent tablets by direct compression.

The SeDeM expert system is a pre formulation tool applied for the prediction of the suitability of a material for direct compression. This innovative tool provides an index of good compressibility of the material indicating its aptitude to be compressed by direct compression. In the study the SeDeM expert system has been applied for the prediction of the behavior of the material to be used in the formulation of effervescent tablets by direct compression. Different formulations were developed on the basis of the results of the SeDeM expert system. Various parameters for the material as per the SeDeM expert system were determined according to their official and reported methods. Powder blend for different formulations was evaluated for their rheological properties while tablets were evaluated for various official and unofficial tests. Suitability of the material for direct compression was successfully predicted using the SeDeM expert system. Domperidone was found unsuitable for direct compression. During formulation all excipients responded as they were predicted as per the SeDeM expert system. Tablets produced using the resultant formulations were having sufficient mechanical strength, free of premature effervescence and were capable to be scaled up for commercial manufacturing.

Report: screening of selected medicinal plants for their enzyme inhibitory potential - a validation of their ethnopharmacological uses.

In present study four medicinal plants namely Valeriana wallichii, Xanthium strumarium, Achyranthes aspera and Duchesnea indica belonging to different families were collected in Khyber Pakhtunkhwa province and crude extract and subsequent fractions were analyzed for their inhibitory potential against acetylcholinesterase, butyrylcholinesterase and α-glucosidase enzymes. Valeriana wallichii, Xanthium strumarium and Achyranthes aspera were significantly active against cholinesterases. Chloroform and ethylacetate fractions of Valeriana wallichii exhibited significant activity against acetylcholinesterase (IC50: 61µg/ml) and butyrylcholinesterase enzymes (IC50: 58µg/ml), respectively. Similarly ethylacetate fraction of Achyranthes aspera showed significant activity against acetylcholinesterase (IC50: 61 µg/ml) and butyrylcholinesterase enzymes (IC50: 61 µg/ml), respectively. In case of α-glucosidase enzyme, the chloroform fraction of Xanthium strumarium exhibited significant inhibitory activity (IC50: 72 µg/ml) as compared to the standard compound acarbose (IC50: 483 µg/ml). Duchesnea indica showed no such activities.

In vivo analgesic, anti-inflammatory and molecular docking studies of S-naproxen derivatives.

In the current studies two naproxen derivatives (NPD) were evaluated for analgesic and anti-inflammatory properties. The acetic acid and hot plate animal models were used to screen the compounds for analgesic potential. While the anti-inflammatory potential was evaluated through animal paw edema, induced by several inflammatory mediators (carrageenan, bradykinin, and prostaglandin E2), the xylene-induced ear edema was also used as an inflammatory model. Both NPDs showed significant (p < 0.001) antinociceptive effects in the acetic acid-induced writhing paradigm. In the case of the hot plate, the NPD 1 at the tested dose of 5 mg/kg enhanced the latency time after 60 min of injection, which remained significant (p < 0.001) up to the end of the experiment duration. The maximum percent inhibition of NPD 1 was 87.53. The naloxone injection significantly lowered the latency time of NPD 1 as compared to NPD 2. Regarding the anti-inflammatory effect, both of the tested NPDs demonstrated a significant reduction in paw edema against various inflammatory mediators, as mentioned above; however, the anti-inflammatory effect of NPD 1 was better. The maximal percent inhibition by NPD 1 and 2 was 43.24 (after 60 min) and 45.93 (after 90 min). A considerable effect also resulted from xylene-induced ere edema. Further, a molecular docking study was carried out to investigate the binding modes of the NPD. The docking analysis revealed that the NPD significantly interacted with the COX2 enzyme. Furthermore, molecular dynamics simulation was carried out for the docked complexes. The MD simulation analysis revealed the high stability of the two naproxen derivatives.

Synthesis of novel hydrazide Schiff bases with anti-diabetic and anti-hyperlipidemic effects: in-vitro, in-vivo and in-silico approaches.

The increasing global incidence of non-insulin-dependent diabetes mellitus (NIDDM) necessitates innovative therapeutic solutions. This study focuses on the design, synthesis and biological evaluation of Schiff base derivatives from 2-bromo-2-(2-chlorophenyl) acetic acid, particularly hydrazone compounds 4a and 4b. Both in-vitro and in-vivo assays demonstrate these derivatives' strong antidiabetic and anti-hyperlipidemic properties. In a 15-d experiment, we administered 4a and 4b at doses of 2.5 and 5 mg/kg body weight, which effectively improved symptoms of alloxan-induced diabetes in mice. These symptoms included weight loss, increased water consumption and high blood glucose levels. The compounds also normalized abnormal levels of total cholesterol (TC), triacylglycerol (TG) and low-density lipoprotein cholesterol (LDL-C), while raising the levels of high-density lipoprotein cholesterol (HDLC). Computational analysis showed that these compounds effectively inhibited the α-glucosidase enzyme by interacting with key catalytic residues, specifically Asp214 and Asp349. These computational results were confirmed through in-vitro tests, where 4a and 4b showed strong α-glucosidase inhibitory activity, with IC50 values of 0.70 ± 0.11 and 10.29 ± 0.30 µM, respectively. These compounds were more effective than the standard drug, acarbose, which had an IC50 value of 873.34 ± 1.67 µM. Mechanistic studies further indicated competitive inhibition, reinforcing the therapeutic potential of 4a and 4b for NIDDM treatment.Communicated by Ramaswamy H. Sarma.

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.

Multiple design and modelling approaches for the optimisation of carbon felt electro-Fenton treatment of dye laden wastewater.

This study utilizes artificial intelligence and statistical modelling to optimize the operating parameters of a carbon-based electro-Fenton process for purifying model dye (RB19)-contaminated wastewater. Multilevel experimental Box-Behnken and uniform deisgns (BBD, UD) with four variables were analysed using polynomial regression analysis (PRA) and artificial neural networks (ANN), while the process optimisation was done using desirability function. For the given testing range but different design matrices and runs, both designs predicted a maximum RB19 removal (RB19-RR) of 90 ± 2.1% at lowest energy consumption (EC) of 0.44 ± 2.5 Wh, when voltage, Na2SO4, FeSO4, and time were maintained as follows: 4-5.3 V, 7-11 mM, 0.4-0.6 mM, and 35-40 min, respectively. All the design-model combinations portrayed the similar senitivity analyses, revealing that RB19 degradation and EC are primarily influenced by electrolysis time and voltage. The performance assessment demonstrated that all the design-model combinations also excellently predicted for unseen conditions as the maximum root mean squared error (RMSE) value for RB19-RR was 4.07, while it was 0.072 for EC, however, BBD-ANN performance proved to be slightly better than others. Having ∼57% less experimentation, UD based models managed to accurately predict the results for unseen conditions as the statistical errors were quite insignificant, even in some cases, RMSE found to be less for UD compared to BBD, elucidating the potential of uniform design as an alternative of conventional factorial designs. Nevertheless, the prediction accuracy is also dependent on modelling approach, as in some cases ANN failed to predict the response precisely specially when dealing with small data. Furthermore, techno-economic evaluation results spell out the efficacy of carbon felt based enhanced electro-Fenton process as promising environmental remediation technology and highlight its practical implication from view of operational cost.

Analgesic and antiinflammatory activities of taxoids from Taxus wallichiana Zucc.

A study was conducted to identify constituents that might be responsible for analgesic and antiinflammatory conditions. Tasumatrol B, 1,13-diacetyl-10-deacetylbaccatin III (10-DAD) and 4-deacetylbaccatin III (4-DAB) were isolated from the bark extract of Taxus wallichiana Zucc. All the compounds were assessed for analgesic and antiinflammatory activities using an acetic acid-induced writhing model, a hot-plate test, a carrageenan-induced paw oedema model, a cotton-pellet oedema model and in vitro lipoxygenase inhibitory assay. All the compounds, especially tasumatrol B, revealed significant analgesic activity in comparison to a saline group based on an acetic acid-induced model. Similarly all of the test compounds, particularly tasumatrol B, showed significant antiinflammatory activity. However, all the compounds failed to exhibit any considerable activity in of the hot-plate test and the in vitro lipoxygenase inhibitory assay. This study has highlighted the potential of tasumatrol B to be further explored as a new lead compound for the management of pain and inflammation, one that has been discovered by scientific validation of the traditional medicinal use of T. wallichiana Zucc.

Safety and efficacy of ARNI (valsartan/sacubitril) vs ACEI (enalapril) in acute heart failure - A prospective observational study.

OBJECTIVE: To compare the safety and efficacy of valsartan/sacubitril (angiotensin receptor neprilysin inhibitor [ARNI]) against enalapril (angiotensin-converting enzyme inhibitor [ACEI]) in patients with acute heart failure at 6-month follow-up. METHODS: In this prospective, single centre, and observational study conducted between September 2017 and February 2020 in India, patients with acute decompensated heart failure with reduced ejection fraction (<40%) were included. Patients were divided in two groups: valsartan/sacubitril (ARNI) group and enalapril (ACEI). Patients were followed up for at least 6 months after administration of first dose and were evaluated for safety, efficacy, and tolerability of target drug. Student's independent t-test was employed for comparing continuous variables. Chi-square test or Fisher's exact test, whichever appropriate, was applied for comparing categorical variables. RESULTS: A total of 200 patients were included in the present study, 100 each in ARNI and ACEI group. The mean age of the population was 61.2 ± 8.4 years and 62.6 ± 8.6 years in ARNI group and ACEI group, respectively. The mean maximum tolerated dose by population in ARNI group was 203.6 mg and 8.9 mg in ACEI group. Readmission for heart failure were seen significantly higher in ACEI group than ARNI group (p value = 0.001). Parameters like ejection fraction, left ventricular end diastolic and systolic dimensions, 6 min walk test and Kansas City Cardiomyopathy Questionnaires (KCCQ) showed p values < 0.05 between the groups. CONCLUSION: The ARNI study group showed better safety and efficacy outcomes at the end of 6 months follow-up compared to ACEI group.

Design and Characterization of Paclitaxel-Loaded Polymeric Nanoparticles Decorated With Trastuzumab for the Effective Treatment of Breast Cancer.

The aim of the study was to design and formulate an antibody-mediated targeted, biodegradable polymeric drug delivery system releasing drug in a controlled manner to achieve a therapeutic goal for the effective treatment of breast cancer. Antibody-mediated paclitaxel-loaded PLGA polymeric nanoformulations were prepared by the solvent evaporation method using different experimental parameters and compatibility studies. The optimized formulations were selected for in vitro and in vivo evaluation and cytotoxicity studies. The in vitro drug release studies show a biphasic release pattern for the paclitaxel-loaded PLGA nanoparticles showing a burst release for 24 h followed by an extended release for 14 days; however, a more controlled and sustained release was observed for antibody-conjugated polymeric nanoparticles. The cytotoxicity of reference drug and paclitaxel-loaded PLGA nanoparticles with and without antibody was determined by performing MTT assay against MCF-7 cells. Rabbits were used as experimental animals for the assessment of various in vivo pharmacokinetic parameters of selected formulations. The pharmacokinetic parameters such as Cmax (1.18-1.33 folds), AUC0-t (39.38-46.55 folds), MRT (10.04-12.79 folds), t1/2 (3.06-4.6 folds), and Vd (6.96-8.38 folds) have been increased significantly while clearance (4.34-4.61 folds) has been decreased significantly for the selected nanoformulations as compared to commercially available paclitaxel formulation (Paclixil®). The surface conjugation of nanoparticles with trastuzumab resulted in an increase in in vitro cytotoxicity as compared to plain nanoformulations and commercially available conventional brand (Paclixil®). The developed PLGA-paclitaxel nanoformulations conjugated with trastuzumab have the desired physiochemical characteristics, surface morphology, sustained release kinetics, and enhanced targeting.

Bioequivalence of 2 azithromycin capsule formulations: a randomized, single-dose, open-label, 2-period crossover study in healthy male pakistani volunteers.

BACKGROUND: Approximately 68 brands of azithromycin capsule formulations are available in Pakistan; however, published data on their bioequivalence in the Pakistani population are not available. OBJECTIVE: Upon instructions from and approval of the Ministry of Health, Pakistan, this study was designed to evaluate the bioequivalence of a locally manufactured azithromycin capsule formulation with a reference formulation from a multinational manufacturer. This study compared dissolution profiles, relative bioavailability, and other pharmacokinetic parameters of the 2 formulations. METHODS: A single oral 500-mg dose of the 2 formulations was administered to 12 healthy adult Pakistani male volunteers under fasting conditions in a randomized, open-label, 2-period crossover study. The trial included collection of blood samples over 48 hours and a 2-week washout period. Azithromycin serum concentrations were quantified using a validated RP-HPLC/ultraviolet (UV) detection method. These results were used to determine the intended pharmacokinetic parameters. As mandated by the US Food and Drug Administration and the European Medicine Agency, the test and reference formulations were considered bioequivalent if the 90% CIs of the geometric mean ratios for the log-transformed values of their pharmacokinetic parameters were within the predetermined range of 0.8 to 1.25. RESULTS: When subjected to a simple model independent approach of dissolution profile comparison, f 1 (difference) and f 2 (similarity factor) were found to be 5.47 and 70.04, respectively. Similarly, the 2 azithromycin capsule formulations were well tolerated by all volunteers. Low %CV of the pharmacokinetic parameters at a sample size of 12 and significance level of 0.05 contributed to acceptable (>0.8) power of the test. The 90% CIs for the ratios of Cmax, AUC0-48, Tmax, t1/2, and mean residence time, respectively, were 0.83-0.93, 0.85-1.10, 0.86-1.08, 0.92-1.17, and 0.92-1.16. CONCLUSION: This single-dose study found that test and reference formulations met the regulatory criteria for bioequivalence in these fasted, healthy male Pakistani volunteers.

Preparation and in-vitro in-vivo evaluation of sustained release matrix diclofenac sodium tablets using PVP-K90 and natural gums.

Conventional dosage form is nowadays mostly replaced by sustained release formulation in order to increase drug efficacy and patient compliance. The sustained release properties of the PVP K90 alone and in combination with guar gum, xanthan gum and gum tragacanth were evaluated using diclofenac sodium (100 mg/tablet) as a model drug. Tablets were processed using wet granulation method and evaluated for sustained drug release properties. The drug release from the formulations was studied in relationship with Commercially available Diclofenac Sodium SR, used as a reference tablets and results were expressed as similarity (f1) and differential factor (f2). The tablets prepared using PVP K90 160 mg/tablet sustained the release of diclofenac sodium for 12 hours. Formulations where the PVP K90 was partially replaced with different gums also sustained the release of drug for 12 hours. The release of the drug from these formulations mainly followed Higuchi model and super case-II and Non-Fickian diffusion. The in-vivo drug release was studied in healthy human volunteers using non-blinded cross over, two period design using Diclofenac Sodium SR Tablets as a reference drug. The relative bioavailability of the formulation containing PVP K90 and gum tragacanth was 0.91. The studies showed that the use of the PVP K90 in combination with gum tragacanth both in-vitro and in-vivo sustained the release of the drug.