Comparative bioavailability study with two sodium valproate tablet formulations administered under fasting conditions in healthy subjects.

AIM: To assess the bioequivalence of two sodium valproate formulations in healthy subjects of both sexes. MATERIALS AND METHODS: The study was conducted using an open, randomized, two-period crossover design with a 2-week washout interval. Plasma samples were obtained over a 96-hour period. Plasma concentrations of valproate were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC/MS) with negative ion electrospray ionization. From the sodium valproate plasma concentration vs. time curves, the following pharmacokinetic parameters were obtained Cmax, AUC, tmax, Ke, and T1/2. RESULTS: The geometric mean with corresponding 90% confidence interval for test/reference percent ratios were 104.43% (90% CI 100.42 - 108.61%) for Cmax, 98.11% (90% CI = 94.66 - 101.70%) for AUClast, and 96.71% (90% CI = 92.97 - 100.60%) for AUC0-inf. CONCLUSION: Since the 90% CI for Cmax and AUClast ratios were all inside the 80 - 125% interval proposed by the US Food and Drug Administration Agency (FDA), it was concluded that the new sodium valproate formulation (epilenil 500-mg coated tablet) without food elaborated by Biolab Sanus Farmaceutica Ltda is bioequivalent to depakene formulation for both the rate and the extent of absorption.

Evidence-Based Recommendations for the Oral Health of Patients with Parkinson's Disease.

INTRODUCTION: Patients with Parkinson's disease (PD) present a variety of oral disease that can be worsened by xerostomia and sialorrhea. The patients' physical limitations, for example rigidity and tremor, add to the difficulty of oral care by the general dental surgeon. The objective of the present review was to organize a list of evidence-based recommendations for the oral care of patients with PD. METHODS: A systematic review of the literature was carried out by specialists who selected the relevant papers and created a list of recommendations based upon the literature. RESULTS: Fourteen papers (data reported in 16 articles) were included in this review. Patients with PD had reduced quality of oral health and hygiene, and high prevalence of gingival recession, periodontal disease, dental calculus, tooth decay, tooth mobility and loss, drooling, xerostomia, dysphagia and temporomandibular disorders. Most studies offered class IV evidence, while one paper had class II evidence. CONCLUSION: Patients with PD present poor oral health with conditions that are mostly preventable.

Pharmacodynamic evaluation of L-carnitine and piracetam in muscle injury induced by the chronic use of simvastatin.

OBJECTIVES: To evaluate the effect of L-carnitine and piracetam on the muscle injury induced by simvastatin in healthy male subjects during the therapy with oral doses of 10 mL of a solution containing L-carnitine 100 mg/mL + piracetam 80 mg/mL (test group) or placebo (control group) and 40 mg simvastatin once a day during 35 consecutive days. The effect of L-carnitine and piracetam in the reduction of myopathic symptomatology caused by exercise, as well as safety and tolerability were also evaluated. MATERIALS AND METHODS: This study was performed on two different occasions, of which 42 subjects were investigated on occasion 1 and 19 on occasion 2. Discomfort or pain was evaluated according to modified Borg scale. Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ-glutamyl transferase (γ-GT), creatine kinase (CK), and lactic dehydrogenase (LDH) were evaluated on the 4th, 11th, 18th, 25th, and 32nd day after therapy, and before and until 4 hours after an exercise test performed on a treadmill on day 36. RESULTS: A higher incidence of pain or discomfort was observed in the control group than in the test group, mainly in occasion 1 (29% vs. 62% experienced pain or discomfort in any period, p = 0.0295). The serum levels of AST, ALT, and LDH were statistically different, with lower values in the test group compared to the control group. CONCLUSION: Concomitant use of L-carnitine and piracetam might have a muscle-protective effect and protection against simvastatin-induced myalgia. Furthermore, the formulation was safe and well tolerated by the subjects investigated in this trial.

Bioavailability study of two 81-mg coated tablet formulations of acetylsalicylic acid in fed healthy subjects
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OBJECTIVE: To perform a comparative bioavailability study between a test (re-formulation) and a reference acetylsalicylic acid formulation (Ecasil-81, 81 mg coated tablet) in healthy subjects under fed condition. MATERIALS AND METHODS: Healthy subjects (n = 48) were included in this monocentric, open-label, randomized, two-way crossover pharmacokinetic study. They received a single 81-mg oral dose of a test or a reference formulation of acetylsalicylic acid under fed condition, with a 7-day washout period between the treatments. Blood samples were collected over a period of 36 hours. The salicylic acid plasma concentration was measured by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Pharmacokinetic analysis was performed using WinNonlin software. RESULTS: The geometric mean and 90% confidence interval of test/reference formulation ratios were 109.32% (102.54 - 116.54%) and 106.94% (102.97 - 111.07%) for salicylic acid Cmax and AUC0-last, respectively. Food decreased the AUC and Cmax (p < 0.001) and delayed the tmax (p = 0.0077). The investigated women presented higher AUC0-∞ and Cmax values (p < 0.001) than men. The clinical and laboratory exams did not show significant alterations. CONCLUSION: The re-formulation is bioequivalent to the reference formulation regarding the absorption extent and rate in fed healthy subjects. The administration of acetylsalicylic acid with food decreased its bioavailability. Moreover, differences in salicylic acid disposition related to sex were observed. The treatments were well tolerated by the investigated subjects.

Comparative bioavailability of two zolpidem hemitartrate formulations in healthy human Brazilian volunteers using high-performance liquid chromatography coupled to tandem mass spectrometry.

To assess the bioequivalence of two zolpidem hemitartrate formulations in 30 healthy volunteers. Plasma samples were obtained over a 24 h period. Plasma concentrations of zolpidem were analyzed by liquid chromatography coupled to tandem mass spectrometry with positive ion electrospray ionization using multiple reaction monitoring. Values of peak concentration (Cmax ), area under curve (AUC), half-life, elimination constant, volume of distribution and clearance showed statistically significant differences when comparing women (604.34 ng h/ml, 127.36 ng/ml, 4.4 h, 0.18 1/h, 50.56 L and 8.55 L/h, respectively) and men (276.1 ng h/ml, 70.9 ng/ml, 3.3 h, 0.26 1/h, 91.42 L and 24.34 L/h, respectively), receiving the same dose (5 mg), respectively. The geometric means with corresponding 90% confidence interval for Test/Reference percentage ratios were 99.73% (CI 93.69-106.16) for Cmax, 97.44% (90% CI = 91.85-103.37%) for area under curve of plasma concentration until the last concentration observed (AUClast ) and 98.30% (90% CI = 92.48-104.49) for the area under curve between the first sample (pre-dosage) and infinity (AUC0-inf ). Since the 90% CI for AUClast , AUC0-inf and Cmax ratios were within the 80-125% interval proposed by the US Food and Drug Administration, it was concluded that zolpidem hemitartrate formulation (5 mg orodispersible tablet) is bioequivalent to the zolpidem hemitartrate formulation (Patz SL 5 mg sublingual tablet) with regard to both the rate and the extent of absorption. A new formulation of zolpidem 2.5 mg may be useful in women for the same clinical benefits as the 5 mg formulation in men.

Development, Validation of LC-MS/MS Method and Determination of Pharmacokinetic Parameters of the Stroke Neuroprotectant Neurounina-1 in Beagle Dog Plasma After Intravenous Administration.

Neurounina-1 [chemical name: 7-nitro-5-phenyl-1-(pyrrolidin-1-ylmethyl)-1H-benzo[e][1,4]diazepin-2(3H)-one] is a new compound provided with relevant neuroprotective effect during stroke and in neonatal hypoxia by increasing the Na+/Ca2+ exchanger (NCX) isoforms NCX1 and NCX2 activity. This study shows for the first time, the development and validation of a sensitive and selective method for analysis of neurounina-1 in beagle dog plasma by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The sample preparation consisted of extraction of the analyte and the internal standard (IS) (ropivacaine) from plasma (50 µL) by liquid-liquid extraction using acetonitrile (100 µL). The selected reaction monitoring mode of the positive ion was performed and the precursor to the product ion transitions of m/z 365 > 83 and m/z 275 > 126 were used to measure the derivative of neurounina-1 and ropivacaine. The chromatographic separation was achieved using a Phenomenex C18 Luna (150 mm × 4.6 mm × 5 µm) analytical column with an isocratic mobile phase composed of methanol/acetonitrile/water (50/40/10, v/v/v) + 0.1% formic acid + 1 M ammonium formate. The method was linear over a concentration range of 1-500 ng/mL. The method was applied to evaluate the pharmacokinetics of neurounina-1 after a single intravenous administration of three different doses (0.1 mg/kg, 0.3 mg/kg, and 1 mg/kg) to beagle dogs (n = 5). The mean AUC0-tlast values were 26.10, 115.81, and 257.28 ng∗h/mL following intravenous administration of 0.1, 0.3, and 1 mg/kg, respectively. Linear pharmacokinetics was observed up to 1.0 mg/kg. The neurounina-1 was rapidly eliminated, with mean CL values of 46.24, 47.57, and 69.15 L/h, Vd of 130.31, 154.15, and 210.79 L and t1/2 of 2.14, 2.54, and 2.04 h after intravenous administration of 0.1, 0.3, and 1 mg/kg, respectively. This new analytical method allows the rapid determination of the neurounina-1, a new developed compound, able to exert a remarkable neuroprotective effect in the low nanomolar range.

Randomized, double-blind, phase III clinical study of a novel nanotechnological topical anesthetic formulation containing lidocaine 25 mg/g and prilocaine 25 mg/g (nanorap) in skin phototypes I-III patients with ablative fractional CO2 laser treatment indication in the forehead.

BACKGROUND AND OBJECTIVES: Nanotechnology may increase the speed of penetration into the skin. This study evaluated the efficacy, safety, and pharmacokinetics of a novel topical anesthetic nanocapsule formulation (2 g) containing 2.5% lidocaine and 2.5% prilocaine (nanorap-test formulation) compared to placebo (control formulation) in skin types I-III patients of both sexes submitted to the ablative fractional CO2 laser treatment. METHODS: The patients (n = 120) included in this double-blind, single-center, randomized trial, received topical application of 2 g of the test formulation (50 mg lidocaine + 50 mg prilocaine) and placebo on the forehead region. Efficacy was assessed as pain sensation in four quadrants of each side of the forehead using a visual analogue scale immediately (0 min) and at 30, 60, and 90 minutes after laser application compared to placebo. The safety and tolerability of the test product were evaluated based on the occurrence of systemic adverse events as well as the occurrence of immediate and late skin reactions. Pharmacokinetic evaluation was performed in plasma of eight patients using a validated LC-MS/MS method for drugs quantification. RESULTS: Nanorap induced a clinically significant reduction in the pain assessment at all evaluated times (57.2%, 41.6%, 38.6%, and 37.3% at 0, 30, 60, and 90 minutes after drug application, respectively. Mean values of Cmax were 14.20 and 5.36 ng/ml and tmax were 3.5 and 1.8 hour for lidocaine and prilocaine, respectively. No systemic adverse events were observed. CONCLUSION: The nanorap formulation demonstrated a clinically and statistically significant efficacy providing analgesia after the ablative fractional CO2 laser therapy in the investigated patients, when compared to placebo. The product also presented good safety and tolerability. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Pharmacokinetics of Riluzole in Beagle Dogs.

BACKGROUND: Riluzole is a benzothiazole anticonvulsant used in the treatment of patients with amyotrophic lateral sclerosis and it is being investigated for clinical use in patients with spinal cord injury. The present study evaluated the pharmacokinetics of riluzole in beagle dogs after oral dose administration. METHODS: The oral doses (1.5, 5, 15 and 50 mg/kg) of riluzole were administered to beagle dogs and blood samples were collected from 0 h to 24 h post drug administration. Riluzole was quantified by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). RESULTS: The method was sensitive, precise, accurate and selective to riluzole quantification in plasma of beagle dogs. The pharmacokinetics following oral administration was linear from 1.5 to 15 mg/kg and the t1/2 was 2.16, 1.5, 1.8 and 3.0 h after oral administration of 1.5, 5.0, 15 and 50 mg/kg riluzole. CONCLUSION: The riluzole pharmacokinetics was linear up to 15 mg/kg and had a significantlyshorter t1/2 in beagle dogs than in humans.

Impact of Bariatric Surgery on the Pharmacokinetics Parameters of Amoxicillin.

BACKGROUND: Bariatric surgery leads to several anatomo-physiological modifications that may affect pharmacokinetic parameters and consequently alter the therapeutic effect of drugs, such as antibiotics. The pharmacokinetics of oral amoxicillin after Roux-en-Y gastric bypass (RYGB) surgery is unknown. OBJECTIVES: The objective of this study was to evaluate the impact of bariatric surgery on the pharmacokinetics of amoxicillin. METHODS: This study was performed as a randomized, open-label, single-dose clinical trial, with two periods of treatment, in which obese subjects (n = 8) received an amoxicillin 500 mg capsule orally before and 2 months after the RYGB surgery. The amoxicillin plasma concentration was determined by liquid chromatography coupled to mass spectrometry (LC-MS/MS). RESULTS: After the surgery, the mean weight loss was 17.03 ± 5.51 kg, and mean body mass index (BMI) decreased from 46.21 ± 2.82 to 38.82 ± 3.32 kg/m2. The mean amoxicillin area under the plasma concentration versus time curve from time zero to the time of the last quantifiable concentration (AUC0-tlast) increased significantly (3.5-fold); the maximum plasma concentration (Cmax) increased 2.8-fold after the bariatric surgery. No correlation was found between amoxicillin absorption, BMI, and weight loss percentage. CONCLUSION: The alterations observed in the amoxicillin pharmacokinetics suggest that obese subjects included in this trial had a substantially increase in amoxicillin systemic exposure after RYGB surgery. However, despite this increase, its exposure was lower than the values reported for non-obese volunteers. TRIAL REGISTRATION: Identifiers: NCT03588273.

Capecitabine bioequivalence in healthy volunteers.

Capecitabine is a prodrug and is selectively activated by tumor cells to its cytotoxic moiety, 5-fluorouracil, by thymidine phosphorylase, which is generally expressed at high levels in tumors. Clinical and pharmacokinetic studies of capecitabine have been performed in patients with cancer. This study aims to evaluate the bioequivalence of two capecitabine formulations (150-mg tablet) using healthy male subjects under nonfasting conditions. The study was conducted as an open, randomized, three-period, semi-replicated design with three sequences (RRT, RTR, TRR) with a 1-week washout interval. The subjects were selected for the study after having their health status previously assessed by a clinical evaluation and laboratory tests (biochemical and hematological parameters, and urinalysis). A single capecitabine tablet (150 mg) was given in each occasion. Plasma capecitabine concentrations were analyzed by liquid chromatography coupled with tandem mass spectrometry (HPLC/MS/MS) with positive ion electrospray ionization using multiple reactions monitoring (MRM). The geometric mean and 90% confidence intervals (CI) of capecitabine/Xeloda® (T/R) percent ratio were 104.34% (98.74 - 110.25%) for AUClast, 103.06% (97.48 - 108.96%) for AUCinf, and 104.07% (88.13 - 122.90%) for Cmax. Since the 90% CI for Cmax, AUClast, and AUCinf ratios were all inside the 80 - 125% interval proposed by the US Food and Drug Administration Agency, it was concluded that the capecitabine formulation elaborated by Eurofarma Laboratórios Ltda. is bioequivalent to Xeloda® formulation for both the rate and the extent of absorption. The drug was well tolerated by the subjects, indicating that it is safe to perform capecitabine bioequivalence studies in healthy male subjects.
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The rabbit vagina as an in vivo model for vaginal fenticonazole permeability and toxicity.

INTRODUCTION: Vaginal route is often used in topical antifungal formulations. Vaginal permeability assays are generally performed as in vitro tests. METHOD: An in vivo vaginal permeability assay was developed using female rabbits. Fenticonazole permeability was evaluated by assessing fenticonazole bioavailability in plasma by liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS). Toxicity was monitored histopathologically after 8 consecutive days of antifungal treatment (20 mg/animal). RESULTS: The method of quantification was linear with a lower limit of quantification (LLOQ) of (0.1 ng/mL). The area-under-the-curves (AUC) of fenticonazole on day 1 and 8 of treatment were 280.3 ±â€¯86.1 ng/mL ∗ h and 805.7 ±â€¯252.4 ng/mL ∗ h, respectively. The calculated systemic bioavailability was 12.73% ±â€¯0.14%. No signs of toxicity were observed both macroscopically and histologically after 8 days fenticonazole treatment. DISCUSSION: The plasma levels of fenticonazole observed in rabbits are similar to that observed in human. Rabbit vagina may be a suitable model to evaluate vaginal antifungal formulations.

Propafenone quantification in human plasma by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry in a bioequivalence study
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Propafenone is an antiarrhythmic drug applied to ventricular arrhythmias, initially recognized as a sodium channel blocker. This study aims to evaluate the bioequivalence of two propafenone formulations (300 mg tablet) in healthy subjects under non-fasting conditions. The study was conducted as an open, randomized, 2-period design with a 2-sequence (RT, TR) with a 1-week washout interval. The subjects were selected for the study after having their health status previously assessed by a clinical evaluation and laboratory tests (biochemical and hematological parameters, and urinalysis). Debrisoquine phenotype of healthy subjects was determined by analysis of urinary excretion of debrisoquine and its major metabolite, 4-hydroxydebrisoquine. A single propafenone tablet (300 mg) was given in each occasion. Plasma propafenone concentrations were analyzed by liquid chromatography coupled to tandem mass spectrometry (HPLC/MS/MS) with positive ion electrospray ionization using multiple reactions monitoring (MRM). The geometric mean and 90% confidence intervals (CI) of propafenone/Ritmonorm® (T/R) percent ratio were 100.44% (88.39 - 114.13%) for AUClast, 99.84% (90.31 - 110.36%) for AUCinf, and 99.30% (90.08 - 109.47%) for Cmax. Since the 90% CI for Cmax, AUClast, and AUCinf ratios were all inside the 80 - 125% interval proposed by the US Food and Drug Administration Agency, it was concluded that the propafenone formulation elaborated by Biolab Sanus Farmacêutica Ltda. is bioequivalent to Ritmonorm® formulation for both the rate and the extent of absorption. The drug was well tolerated by the subjects, indicating that it is safe to perform propafenone bioequivalence studies in healthy subjects with intermediate/extensive metabolism.
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Bioequivalence study between a fixed-dose single-pill formulation of nebivolol plus hydrochlorothiazide and separate formulations in healthy subjects using high-performance liquid chromatography coupled to tandem mass spectrometry.

Systemic arterial hypertension is a major risk factor for cerebrovascular disease. Therefore, adequate control of blood pressure is of enormous importance. One of the many fixed-dose single-pill antihypertensive formulations available on the market is the combination of nebivolol and hydrochlorothiazide. The objective of this study was to develop two distinct high-performance liquid chromatography coupled to tandem mass spectrometry methods to simultaneously quantify nebivolol and hydrochlorothiazide in human plasma. The methods were employed in a bioequivalence study, the first assay involving a nebivolol fixed-dose single-pill formulation based on healthy Brazilian volunteers. Nebilet HCT™ (nebivolol 5 mg + hydrochlorothiazide 12.5 mg tablet, manufactured by Menarini) was the test formulation. The reference formulations were Nebilet™ (nebivolol 5 mg tablet, manufactured by Menarini) and Clorana™ (hydrochlorothiazide 25 mg tablet, manufactured by Sanofi). For both analytes, liquid-liquid extraction was employed for sample preparation and the chromatographic run time was 3.5 min. The limits of quantification validated were 0.02 ng/mL for nebivolol and 1 ng/mL for hydrochlorothiazide. Since the 90% CI for Cmax , AUC(0-last) and AUC(0-inf) individual test/reference ratios were within the 80-125% interval indicative of bioequivalence, it was concluded that Nebilet HCT™ is bioequivalent to Nebilet™ and Clorana™.

Assessment of pharmacokinetic interaction between piracetam and l-carnitine in healthy subjects.

A rapid, sensitive and specific method for quantifying piracetam in human plasma using Piracetam d-8 as the internal standard (IS) is described. The analyte and the IS were extracted from plasma by one-step precipitation of protein using an acetonitrile (100%). The extracts were analyzed by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry (HPLC-MS/MS). The method had a chromatographic run time of 3.8 min and a linear calibration curve over the range 0.5-50 µg/mL (r > 0.99). This LC-MS-MS procedure was used to assess the bioavailability of two piracetam formulations: piracetam + l-carnitine (Piracar®; 270/330 mg tablet) and piracetam (Nootropil®; 800 mg tablet) in healthy volunteers of both sexes. The geometric means with corresponding 90% confidence interval (CI) for test/reference percentage ratios were 88.49% (90% CI = 81.19 - 96.46) for peak concentration/dose and 102.55% (90% CI = 100.62 - 104.51) for AUCinf /dose. The limit of quantitation of 0.5 µg/mL is well suited for pharmacokinetic studies in healthy volunteers. It was concluded that piracetam (Piracar®; 270/330 mg tablet) has a bioavailability equivalent to the piracetam (Nootropil®; 800 mg tablet) formulation with regard to both the rate and the extent of absorption.

Pharmacokinetic and pharmacodynamic evaluation of a nanotechnological topical formulation of lidocaine/prilocaine (nanorap) in healthy volunteers.

BACKGROUND: Nanorap is a new nanotechnological formulation for topical anesthesia composed of lidocaine (2.5%) and prilocaine (2.5%). This study evaluated the pharmacokinetics of Nanorap. For the determination of lidocaine and prilocaine in human plasma, a new method using high-performance liquid chromatography coupled with tandem mass spectrometry was developed. Nanorap pharmacodynamic (PD) and its physical proprieties were also evaluated. METHODS: Nanorap was administered by topical application of 2 g to healthy volunteers, and blood samples were collected for the pharmacokinetics analysis. The drugs were extracted from plasma by liquid-liquid extraction with ether/hexane (80/20, vol/vol). The chromatography separation was performed on a Genesis C18 analytical column 4 µm (100 × 2.1 mm i.d.) with a mobile phase of methanol/acetonitrile/water (40/30/30, for lidocaine, and 50/30/20, for prilocaine, vol/vol/vol) + 2 mM of ammonium acetate and ropivacaine as internal standard. The drugs were quantified using a mass spectrometer with an electrospray source in the electrospray ionization positive mode configured for multiple reaction monitoring. The PD of Nanorap was evaluated with the use of a visual analog scale. Nanorap was characterized by cryofracture. RESULTS: The chromatography run-time was 5.5 minutes for lidocaine and 3.3 minutes for prilocaine, and the lower limit of quantification was 0.05 ng/mL for both drugs. Mean Cmax was 6.62 and 1.72 ng/mL for lidocaine and prilocaine, respectively. Median Tmax was 6.5 hours for both drugs. Nanocapsules had a mean size of 88 nm and mean drug association of 92.5% and 89% for lidocaine and prilocaine, respectively. The PD study showed that Nanorap has a sufficient analgesic effect (>30% reduction in pain) after 10 minutes of application. CONCLUSIONS: A new simple, selective, and sensitive method for determination of lidocaine and prilocaine in human plasma was developed. Nanorap generated safe plasma levels of the drugs and satisfactory analgesic effect.

Propylthiouracil quantification in human plasma by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry: application in a bioequivalence study.

UNLABELLED: A rapid, sensitive and specific method for quantifying propylthiouracil in human plasma using methylthiouracil as the internal standard (IS) is described. The analyte and the IS were extracted from plasma by liquid-liquid extraction using an organic solvent (ethyl acetate). The extracts were analyzed by high performance liquid chromatography coupled with electrospray tandem mass spectrometry (HPLC-MS/MS) in negative mode (ES-). Chromatography was performed using a Phenomenex Gemini C18 5µm analytical column (4.6mm×150mm i.d.) and a mobile phase consisting of methanol/water/acetonitrile (40/40/20, v/v/v)+0.1% of formic acid. For propylthiouracil and I.S., the optimized parameters of the declustering potential, collision energy and collision exit potential were -60 (V), -26 (eV) and -5 (V), respectively. The method had a chromatographic run time of 2.5min and a linear calibration curve over the range 20-5000ng/mL. The limit of quantification was 20ng/mL. The stability tests indicated no significant degradation. This HPLC-MS/MS procedure was used to assess the bioequivalence of two propylthiouracil 100mg tablet formulations in healthy volunteers of both sexes in fasted and fed state. The geometric mean and 90% confidence interval CI of Test/Reference percent ratios were, without and with food, respectively: 109.28% (103.63-115.25%) and 115.60% (109.03-122.58%) for Cmax, 103.31% (100.74-105.96%) and 103.40% (101.03-105.84) for AUClast. CONCLUSION: This method offers advantages over those previously reported, in terms of both a simple liquid-liquid extraction without clean-up procedures, as well as a faster run time (2.5min). The LOQ of 20ng/mL is well suited for pharmacokinetic studies. The assay performance results indicate that the method is precise and accurate enough for the routine determination of the propylthiouracil in human plasma. The test formulation with and without food was bioequivalent to reference formulation. Food administration increased the Tmax and decreased the bioavailability (Cmax and AUC).

A Phase I clinical trial of lodenafil carbonate, a new phosphodiesterase Type 5 (PDE5) inhibitor, in healthy male volunteers.

UNLABELLED: Lodenafil carbonate is a new phosphodiesterase Type 5 (PDE5) inhibitor used in treatment of erectile dysfunction. OBJECTIVE: The present study was conducted to evaluate the safety, tolerability, and pharmacokinetics of lodenafil carbonate after administering ascending (1 - 100 mg) single oral doses to healthy male volunteers (n = 33). METHODS: The study was an open label, dose-escalation, Phase I clinical trial involving the administration of single oral doses of lodenafil carbonate. Lodenafil carbonate was administered sequentially, escalating in single doses of 1 mg - 100 mg with a washout period of at least 1 week between each dose. The progression to the next dose was allowed after clinical and laboratory exams, Ambulatory Monitoring of Arterial Pressure (AMAP) without relevant clinical modifications and adverse events without clinical relevancy. Blood samples were collected at pre-dose, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 10, 12, 14, 16, 20 and 24 h post-dosing. Plasma samples for measurement of lodenafil carbonate and lodenafil were analyzed by liquid chromatography coupled to tandem mass spectrometry. RESULTS: No serious adverse events were observed, and none of the subjects discontinued the study due to intolerance. The AMAP measurements, clinical and laboratory exams and ECG revealed no significant changes even at higher doses. Lodenafil carbonate was not detected in any samples, indicating that it acts as a prodrug. The mean lodenafil pharmacokinetic parameters for tmax and t1/2 were 1.6 ( ± 0.4) h and 3.3 ( ± 1.1) h, respectively. This study demonstrated that lodenafil carbonate was well tolerated and showed a good safety profile in healthy male volunteers.

Ciprofibrate quantification in human plasma by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry for pharmacokinetic studies.

A rapid, sensitive and specific method for quantifying ciprofibrate in human plasma using bezafibrate as the internal standard (IS) is described. The sample was acidified prior extraction with formic acid (88%). The analyte and the IS were extracted from plasma by liquid-liquid extraction using an organic solvent (diethyl ether/dichloromethane 70/30 (v/v)). The extracts were analyzed by high performance liquid chromatography coupled with electrospray tandem mass spectrometry (HPLC-MS/MS). Chromatography was performed using Genesis C18 4 µm analytical column (4.6 × 150 mm i.d.) and a mobile phase consisting of acetonitrile/water (70/30, v/v) and 1mM acetic acid. The method had a chromatographic run time of 3.4 min and a linear calibration curve over the range 0.1-60 µg/mL (r>0.99). The limit of quantification was 0.1 µg/mL. The intra- and interday accuracy and precision values of the assay were less than 13.5%. The stability tests indicated no significant degradation. The recovery of ciprofibrate was 81.2%, 73.3% and 76.2% for the 0.3, 5.0 and 48.0 ng/mL standard concentrations, respectively. For ciprofibrate, the optimized parameters of the declustering potential, collision energy and collision exit potential were -51 V, -16 eV and -5 V, respectively. The method was also validated without the use of the internal standard. This HPLC-MS/MS procedure was used to assess the bioequivalence of two ciprofibrate 100mg tablet formulations in healthy volunteers of both sexes. The following pharmacokinetic parameters were obtained from the ciprofibrate plasma concentration vs. time curves: AUC(last), AUC(0-168 h), C(max) and T(max). The geometric mean with corresponding 90% confidence interval (CI) for test/reference percent ratios were 93.80% (90% CI=88.16-99.79%) for C(max,) 98.31% (90% CI=94.91-101.83%) for AUC(last) and 97.67% (90% CI=94.45-101.01%) for AUC(0-168 h). Since the 90% CI for AUC(last), AUC(0-168 h) and C(max) ratios were within the 80-125% interval proposed by the US FDA, it was concluded that ciprofibrate (Lipless 100mg tablet) formulation manufactured by Biolab Sanus Farmacêutica Ltda. is bioequivalent to the Oroxadin (100 mg tablet) formulation for both the rate and the extent of absorption.

Local and cardiorenal effects of periodontitis in nitric oxide-deficient hypertensive rats.

OBJECTIVE: in this study we have assessed the renal and cardiac consequences of ligature-induced periodontitis in both normotensive and nitric oxide (NO)-deficient (L-NAME-treated) hypertensive rats. MATERIALS AND METHODS: oral L-NAME (or water) treatment was started two weeks prior to induction of periodontitis. Rats were sacrificed 3, 7 or 14 days after ligature placement, and alveolar bone loss was evaluated radiographically. Thiobarbituric reactive species (TBARS; a lipid peroxidation index), protein nitrotyrosine (NT; a marker of protein nitration) and myeloperoxidase activity (MPO; a neutrophil marker) were determined in the heart and kidney. RESULTS: in NO-deficient hypertensive rats, periodontitis-induced alveolar bone loss was significantly diminished. In addition, periodontitis-induced cardiac NT elevation was completely prevented by L-NAME treatment. On the other hand L-NAME treatment enhanced MPO production in both heart and kidneys of rats with periodontitis. No changes due to periodontitis were observed in cardiac or renal TBARS content. CONCLUSIONS: in addition to mediating alveolar bone loss, NO contributes to systemic effects of periodontitis in the heart and kidney.