Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Suspensions”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22Linked to original sources

Development of two stable oral suspensions for gabapentin.

Gabapentin is not available in a liquid dosage form for clinical use. This study was designed to develop two oral gabapentin suspensions and determine their stability under refrigeration or at room temperature. Commercially available gabapentin capsules were used to prepare two suspensions: one in extemporaneously prepared 1% methylcellulose in syrup (1:1) and another in equal volumes of commercially available suspending agents/syrup (Ora Plus/Ora Sweet). Each suspension containing gabapentin (100 mg/mL) was stored in 10 plastic prescription bottles; five were stored at 4 degrees C and five at 25 degrees C. Three 500-microL samples were collected immediately after preparation (day 0) and on days 7, 14, 28, 42, 56, 70, and 91. Gabapentin was measured by accurate, reproducible, specific, and stability-indicating high-performance liquid chromatography (n = 15). The observed mean concentrations exceeded 90% of the initial concentrations in both suspensions for 91 days at 4 degrees C and 56 days at 25 degrees C. No change in pH, odor, or physical appearance was observed. On the basis of these results, stable oral suspensions of gabapentin can be prepared and stored in plastic prescription bottles for 91 days at 4 degrees C or 56 days at 25 degrees C.

Acetates↗

Phenytoin pharmacokinetics following oral administration of phenytoin suspension and fosphenytoin solution to rats.

The administration of phenytoin suspension in conjunction with enteral nutrition supplements through nasogastric (NG) feeding tubes to humans has been associated with suboptimal phenytoin absorption, subtherapeutic concentrations, and breakthrough seizures. Postulated mechanisms include chelation to proteins and electrolytes in the enteral feeding, binding to NG tubing, and alterations in gastrointestinal pH resulting in precipitation of phenytoin. The purpose of this pilot study was to evaluate the oral absorption of commercially available fosphenytoin injectable solution compared to phenytoin suspension in the rat to determine whether equivalent oral fosphenytoin and phenytoin suspension doses should be used for future human studies of fosphenytoin oral absorption in the presence of concomitant enteral nutrition. A single oral 30 mg/kg phenytoin equivalents dose of either commercially available fosphenytoin or phenytoin suspension was administered to male Wistar rats following an overnight fast. Blood samples (0.3 ml) for phenytoin plasma concentration were obtained from a jugular vein catheter at baseline and 0.5, 1, 1.5, 2, 3, 4, 5, 8, 12 and 24 h post-study drug administration and analyzed by high performance liquid chromatography (HPLC) (CV% < 6). Mean phenytoin Cmax was 85% [corrected] (P = 0.010) higher in fosphenytoin vs phenytoin treated rats. Tmax was 2.4 h (62%, P=0.021) shorter in fosphenytoin vs phenytoin treated rats. No significant differences in AUClast were found. The presence of a phosphate ester moiety does not appear to inhibit the appearance of phenytoin following oral administration of fosphenytoin. Phenytoin plasma concentration profiles following oral administration of fosphenytoin are characterized by higher Cmax and shorter Tmax values relative to oral administration of phenytoin suspension.

Administration, Oral↗

Intratumoral injection with [(188)Re]rhenium sulfide suspension for treatment of transplanted human liver carcinoma in nude mice.

Hepatocellular carcinoma (HCC) is one of the most common malignancies in China. Direct intratumoral injection of nonremovable radioactive material has been widely studied because it could deliver high doses of radiation to target sites and minimize radiation leakage to non-target organs or tissues. Thirty nude mice bearing SMMC 7721 human liver carcinoma were used for the biodistribution study after intratumoral injection of [(188)Re]rhenium sulfide suspension or sodium [(188)Re]perrhenate solution. Another 30 tumor-bearing mice were divided into six groups, four groups of which were treated with a 0.1 ml [(188)Re]rhenium sulfide suspension at doses of 3.7, 7.4, 18.5, 29.6 MBq by a single intratumoral injection. For control studies, to study the tumor inhibiting ratio, the remaining two groups were injected with nonradioactive rhenium sulfide suspension and Hanks' balanced salt solution, respectively. The injections were repeated 6 days later. The retention percentages of radioactivity (%ID) in tumors injected with [(188)Re]rhenium sulfide suspension were 90.96+/-6.63%, 86.09+/-22.58% and 87.62+/-13.97% at 1, 24 and 48 h, respectively. Tumor inhibition ratios are as high as 89% when the outer space of tumor (0.5-0.6 cm from center) received about 507.6 Gy doses. Intratumoral injection of [(188)Re]rhenium sulfide suspension results in high tumor retention indicating this approach has strong potential for the treatment of hepatic carcinoma.

Animals↗

Effect of hydrodynamic and physicochemical changes on critical flux of milk protein suspensions.

The critical flux during ultrafiltration of whey protein concentrate and sodium caseinate suspensions was investigated. The weak form of critical flux was found for both suspensions. Critical flux of sodium caseinate was higher than that of whey protein concentrate. This could be due to the differences in particle size of the suspensions, resulting in a slower particle back transportation for small particles (whey proteins) compared to the larger casein micelles. Critical flux increased as crossflow velocity increased and decreased as concentration increased, suggesting that critical flux was determined by competition between rate of particle removal from the membrane surface and rate of particle movement towards the membrane surface. Influence of changing pH, addition of NaCl and CaCl2 on the critical fluxes of both protein suspensions was also studied. Increasing pH led to an increase in critical flux for both protein suspensions, suggesting that electrostatic repulsive forces are involved in determining critical flux in both cases. Addition of NaCl gave rise to a decrease in electrostatic interactions due to an increase in ionic strength and zeta potential, and resulted in a decrease in critical flux for sodium caseinate, but had no significant effect for whey protein concentrate. Addition of CaCl2 resulted in a decrease in the critical flux and had a more pronounced influence than NaCl. These results suggest that, in addition to electrostatic repulsive forces, other factors such as structure of protein may be involved in determining the critical flux.

Animals↗

Effect of reaction conditions on the properties and behavior of wood cellulose nanocrystal suspensions.

Sulfuric acid hydrolysis of native cellulose fibers produces stable suspensions of cellulose nanocrystals. Above a critical concentration, the suspensions spontaneously form an anisotropic chiral nematic liquid crystal phase. We have examined the effect of reaction time and acid-to-pulp ratio on nanocrystal and suspension properties for hydrolyzed black spruce acid sulfite pulp. Longer hydrolysis times produced shorter, less polydisperse black spruce cellulose nanocrystals and slightly increased the critical concentration for anisotropic phase formation. Increased acid-to-pulp ratio reduced the dimensions of the nanocrystals thus produced; the critical concentration was increased and the biphasic range became narrower. A suspension made from a bleached kraft eucalyptus pulp gave very similar properties to the softwood nanocrystal suspension when prepared under similar hydrolysis conditions.

Anisotropy↗

Preparation, characterization, and in vivo evaluation of an oil suspension of a bovine growth hormone releasing factor analog.

Pharmacia & Upjohn Inc. has discovered a superior bovine growth hormone releasing factor analog, [IIe2,Ser8,28,Ala15,Leu27,Hse30] bGRF (1-30)-NH-ethyl, acetate salt (U-90699F), for enhancement of animal growth. This report delineates the preparation, characterization, and in vivo evaluation of a U-90699F oil suspension. The oil suspension formulation was selected because of its simplicity, inexpensiveness, and ability to produce sustained U-90699F release. 40% U-90699F monomers were incorporated into Miglyol oil with acceptable injectability. Both reversed-phase-high-pressure liquid chromatography (RP-HPLC) and Fourier transform infrared spectroscopy (FTIR) were utilized to evaluate its chemical and structural stability. This suspension formulation demonstrated no significant changes in concentration as determined by RP-HPLC for 10 weeks at both 25 and 39 degrees C. The U-90699F dispersed in oil also showed no signs of structural conversion from alpha-helix to beta-sheet as monitored by FTIR. However, there was an increase in alpha-helix/disordered coil structure after initial drug incorporation. The suspension was subcutaneously administered to Holstein steers. Areas under the serum somatotropin concentration curve were used to determine the duration of action. It was found that the suspension was able to effectively elevate serum somatotropin for at least 14 days.

Animals↗

Formulation and antitumor activity evaluation of nanocrystalline suspensions of poorly soluble anticancer drugs.

PURPOSE: Determine if wet milling technology could be used to formulate water insoluble antitumor agents as stabilized nanocrystalline drug suspensions that retain biological effectiveness following intravenous injection. METHODS: The versatility of the approach is demonstrated by evaluation of four poorly water soluble chemotherapeutic agents that exhibit diverse chemistries and mechanisms of action. The compounds selected were: piposulfan (alkylating agent), etoposide (topoisomerase II inhibitor), camptothecin (topoisomerase I inhibitor) and paclitaxel (antimitotic agent). The agents were wet milled as a 2% w/v solids suspension containing 1% w/v surfactant stabilizer using a low energy ball mill. The size, physical stability and efficacy of the nanocrystalline suspensions were evaluated. RESULTS: The data show the feasibility of formulating poorly water soluble anticancer agents as physically stable aqueous nanocrystalline suspensions. The suspensions are physically stable and efficacious following intravenous injection. CONCLUSIONS: Wet milling technology is a feasible approach for formulating poorly water soluble chemotherapeutic agents that may offer a number of advantages over a more classical approach.

Animals↗

Inhibition of succinimide formation in aqueous Zn-rHirudin suspensions.

PURPOSE: The formation of succinimide intermediates at Asp-Gly sites and their hydrolysis products, e.g., isoAsp isomers, represents a common source of microheterogeneity in therapeutic proteins. Here we report on the stabilization effect of a zinc chloride induced precipitation of recombinant hirudin HV1 (rHir), an anticoagulant protein. METHODS: rHir was precipitated by zinc chloride at neutral pH to form a Zn-rHir suspension. An Arrhenius-type study (at 50, 40, 30, and 25 degrees C) and a 4 degrees C stability study were performed. Monitoring of rHir, rHir succinimides at Asp33-Gly34 (Q5) and Asp53-Gly54 (Q4), and further side products was by capillary electrophoresis (CE). RESULTS: The activation energies of rHir degradation in both aqueous rHir solution and Zn-rHir suspension were similar, i.e. 104.5 and 110.3 kJ/mol, respectively. Zn-rHir suspension demonstrated improved shelf-life stability (t90%, 95% confidence limit) versus rHir solution, i.e., 23 versus 3 days at 25 degrees C and 292 versus 147 days at 4 degrees C, respectively. In rHir solution, Q4 (Asp53-Gly54 succinimide) levels were slightly above Q5 (Asp33-Gly34 succinimide) levels. In Zn-rHir suspension, however, Q4 succinimide levels dropped markedly whereas Q5 levels were not affected. Correspondingly, in Zn-rHir isoAsp53-rHir levels were reduced but not isoAsp33-rHir levels. CONCLUSIONS: In Zn-rHir suspensions, interactions of zinc and rHir show site-specific inhibition of succinimide formation only at Asp53-Gly54 (Q4), located in the highly flexible C-terminal tail of rHir. In contrast, succinimide formation at Asp33-Gly34 (Q5), located in a less flexible loop domain is not affected, reflecting steric hindrance.

Anticoagulants↗

A comparison of simplified lansoprazole suspension administered nasogastrically and pantoprazole administered intravenously: effects on 24-h intragastric pH.

AIM: To compare the 24-h intragastric pH effects of simplified lansoprazole suspension, 30 mg, administered nasogastrically, with pantoprazole, 40 mg, administered intravenously. METHODS: Thirty-six healthy adults were enrolled and given simplified lansoprazole suspension, 30 mg (nasogastrically), or pantoprazole, 40 mg (intravenously), once daily for five consecutive days in a cross-over fashion. Intragastric pH was monitored at baseline and on Days 1 and 5 of each treatment period. The pharmacokinetic parameters of lansoprazole and pantoprazole were also determined on Days 1 and 5. RESULTS: No statistically significant changes in pharmacokinetic parameters occurred between Days 1 and 5 with either regimen, except for pantoprazole Cmax. On Days 1 and 5, significantly higher mean 24-h intragastric pH values were observed with 30 mg simplified lansoprazole suspension compared with 40 mg intravenous pantoprazole (Day 1, 3.13 vs. 2.67; Day 5, 3.95 vs. 3.61, respectively; P < 0.05). Additionally, 30 mg simplified lansoprazole suspension produced significantly (P < 0.05) higher percentages of time intragastric pH was above 3, 4, 5 or 6 as compared with 40 mg intravenous pantoprazole throughout Days 1 and 5. CONCLUSIONS: A 30 mg dose of simplified lansoprazole suspension administered nasogastrically was consistently more effective at controlling intragastric pH than pantoprazole, 40 mg, administered intravenously.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Budesonide inhalation suspension: a nebulized corticosteroid for persistent asthma.

Guidelines for managing asthma in pediatric patients published by the American Academy of Allergy, Asthma, and Immunology and the American Academy of Pediatrics recommend the use of inhaled corticosteroids for the management of persistent asthma in infants and young children. When these guidelines were published, pressurized metered-dose inhalers and dry-powder inhalers were the only delivery devices available for inhaled corticosteroids in the United States. These devices can be difficult for young children to use correctly. Furthermore, no inhaled corticosteroid was approved in the United States for the treatment of children younger than 4 years. Budesonide inhalation suspension (Pulmicort Respules; AstraZeneca LP, Wilmington, Del) was developed to meet the medication delivery needs of infants and young children with persistent asthma. Pulmicort Respules is the first inhaled corticosteroid approved for administration by means of a nebulizer and the only inhaled corticosteroid approved in the United States for infants as young as 12 months. Budesonide has been studied extensively worldwide. In the United States the tolerability and efficacy of budesonide inhalation suspension were confirmed in 3 placebo-controlled multicenter trials. These studies demonstrated that both once- and twice-daily dosing of budesonide inhalation suspension (0.25-1 mg) improved pulmonary function and ameliorated asthma symptoms in infants and young children with persistent asthma. Budesonide inhalation suspension was well tolerated, and the incidences of reported adverse events were similar among patients in the budesonide, placebo, and conventional asthma therapy groups. This article reviews the results of these studies, as well as the pharmacokinetics, pharmacodynamics, and clinical use of budesonide inhalation suspension.

Administration, Inhalation↗

Particle size determination of a three-component suspension using a laser-scattering particle size distribution analyzer.

In this study, a rapid and accurate particle size determination method using a light-scattering particle size analyzer was developed to measure the particle size and size distribution of a suspension containing three solid components: clotrimazole, triamcinolone, and sarafloxacin, which have different refractive indices. To ensure that data represent the size distribution of the primary particles of the suspension, the optimal sonication prior to and during measurement was determined. It was found that the results obtained using the average relative refractive index (RRI) of the three components agreed with the results obtained using three individual RRIs. In addition, the results from two analysts demonstrated good reproducibility of this method. The size distribution data of the suspension were also compared to those of the bulk drugs. The results showed that the median particle size of this three-component suspension is relatively close to that of clotrimazole, which accounts for 80% of solid particles in the suspension. Furthermore, the results obtained using the light-scattering technique were comparable to those obtained using a polarized light microscope equipped with an image analyzer, indicating acceptable accuracy of this technique.

Anti-Infective Agents↗

Comparison of the physical and chemical stability of niclosamide crystal forms in aqueous versus nonaqueous suspensions.

In an effort to produce physically stable and pharmaceutically acceptable suspensions of niclosamide, this study reports the differences in physical and chemical stability of aqueous vs. nonaqueous suspensions of a niclosamide anhydrate, two monohydrates HA and HB, a 1:1 niclosamide N,N-dimethylformamide solvate, a 1:1 niclosamide dimethyl sulfoxide solvate, a 1:1 niclosamide methanol solvate, and a 2:1 niclosamide tetraethylene glycol hemisolvate. Evaluation of aqueous and nonaqueous suspensions showed that in aqueous suspensions anhydrous, and solvated niclosamide crystal forms were transformed to a monohydrate, HA, which was reasonably stable but which did eventually transform to the most stable monohydrate HB. The order in which these crystal forms transformed to monohydrate HB were: Anhydrate > N,N-dimethylformamide > dimethyl sulfoxide > methanol > tetraethylene glycol > monohydrate HA. In a nonaqueous propylene glycol vehicle, the transformation to the monohydrous forms was not observed and on desolvation the solvated crystals transformed to the anhydrous form. In all cases, immediately upon desolvation or dehydration, the crystal structures of the desolvated materials were similar to that of the solvated materials. However, the isomorphic structures, formed after desolvation, were unstable and rehydrated or resolvated when exposed to the solvent or converted to the anhydrous form in a dry environment. The crystal forms remained chemically stable in both aqueous and nonaqueous suspensions for the length of the study.

Antinematodal Agents↗

Pulmonary peptide delivery: effect of taste-masking excipients on leuprolide suspension metered-dose inhalers.

The purpose of this study was to evaluate the effect of taste-masking excipients on in vitro and in vivo performance of a leuprolide metered-dose inhaler (MDI) suspension formulation. Taste-masking excipients (aspartame and menthol) were added to a leuprolide suspension MDI formulation. The leuprolide MDI formulation with the taste-masking excipients was characterized in terms of milling time, particle size distribution, dose delivery and uniformity, and drug absorption in dogs. The data were compared with a formula that did not contain taste-masking excipients. It was found that the longer milling time for the leuprolide suspension with the taste-masking excipients was required to obtain a similar particle size distribution compared with the formula without taste-masking excipients using a fluid energy mill. Although measurable differences in mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) were not observed between the two formulations, the percent of particles < or = 5 microns and the actuator retention for the formula with the taste-masking excipients were significantly different from the formula without taste-masking excipients using the Marple-Miller cascade impactor. Taste-masking excipients did not show a significant effect on valve delivery and through-can dose uniformity. However, the mean ex-actuator dose was 150.4 mg for the formula with the taste-masking excipients and 162.2 mg for the reference formula, respectively, indicating a significant difference. In tracheostomized dogs, both formulations showed comparable pharmacokinetic parameters including Cmax, Tmax, AUC0-12 and bioavailability (F%), indicating that the taste-masking excipients do not have an effect on lung absorption of leuprolide acetate. Therefore, inclusion of taste-masking excipients in the leuprolide MDI suspension formulation showed a significant impact on drug micronization, exactuator dose, and particle deposition pattern. Mechanistically, the unfavorable performance of leuprolide MDI in the presence of taste-masking excipients could be due to modification of the properties of the suspension itself and alteration of propellant evaporation following actuation.

Administration, Inhalation↗

Stability of lamotrigine in two extemporaneously prepared oral suspensions at 4 and 25 degrees C.

The stability of lamotrigine 1 mg/mL in two extemporaneously prepared oral suspensions at 4 and 25 degrees C was studied. Lamotrigine tablets were ground to powder, and the powder was combined with a 1:1 mixture of Ora-Sweet and Ora-Plus or a 1:1 mixture of Ora-Sweet SF and Ora-Plus (Paddock Laboratories) to produce two 1-mg/mL suspensions. One 100-mg lamotrigine tablet was used to prepare one 100-mL batch of each suspension. The suspensions were stored in amber polyethylene terephthalate prescription bottles at 4 or 25 degrees C. Samples were collected on days 0, 7, 14, 28, 42, 56, 70, and 91 for analysis of lamotrigine content by high-performance liquid chromatography; pH was measured, and the samples were visually observed against a black and white background. The mean concentration of lamotrigine was >99% of the initial concentration in all samples throughout the 91-day study period; there was no change in apparent pH, odor, or physical appearance. Lamotrigine 1 mg/mL in two extemporaneously compounded oral suspensions was stable for 91 days in polyethylene terephthalate prescription bottles at 4 and 25 degrees C.

Administration, Oral↗

A prospective study of simplified omeprazole suspension for the prophylaxis of stress-related mucosal damage.

OBJECTIVES: To determine the efficacy, safety, and cost of simplified omeprazole suspension in mechanically ventilated critically ill patients who have at least one additional risk factor for stress-related mucosal damage. DESIGN: Prospective, open-label study. SETTING: Surgical intensive care and burn unit at a university tertiary care center. PATIENTS: Seventy-five adult, mechanically ventilated patients with at least one additional risk factor for stress-related mucosal damage. INTERVENTIONS: Patients received 20 mL of simplified omeprazole suspension (containing 40 mg of omeprazole) initially, followed by a second 20-mL dose 6 to 8 hrs later, then 10 mL (20 mg) daily. Simplified omeprazole suspension was administered through a nasogastric tube, followed by 5 to 10 mL of tap water. The nasogastric tube was clamped for 1 to 2 hrs after each administration. MEASUREMENTS AND MAIN RESULTS: The primary outcome measure was clinically significant gastrointestinal bleeding determined by endoscopic evaluation, nasogastric aspirate examination, or heme-positive coffee ground material that did not clear with lavage, which was associated with at least a 5% decrease in hematocrit. Secondary efficacy measures were gastric pH measured 4 hrs after omeprazole was first administered, mean gastric pH after omeprazole was started, and the lowest gastric pH during omeprazole therapy. Safety-related outcomes included the occurrence rate of adverse events and pneumonia. No patient experienced clinically significant upper gastrointestinal bleeding after receiving omeprazole suspension. The 4-hr postomeprazole mean gastric pH was 7.1, the mean gastric pH after starting omeprazole was 6.8, and the mean lowest pH after starting omeprazole was 5.6. The occurrence rate of pneumonia was 12%. No patient in this high-risk population experienced an adverse event or a drug interaction that was attributable to omeprazole. CONCLUSIONS: Simplified omeprazole suspension prevented clinically significant upper gastrointestinal bleeding and maintained gastric pH of > 5.5 in mechanically ventilated critical care patients without producing toxicity.

Adolescent↗

Arterial morphology and blood volumes of rats following 10-14 weeks of tail suspension.

We hypothesized that the structure of systemic arteries would be altered following 10-14 wk of hindlimb unloading (tail suspension) in female Sprague-Dawley rats. Tail suspension resulted in atrophy of the soleus muscle (P < or = 0.01) but no significant differences in the mass of the extensor digitorum muscle, heart, or adrenal glands. In anesthetized rats, there was no difference between groups in arterial pressure (approximately 60 mm Hg). The corresponding maximal (topical papaverine) external diameter (ED) of femoral arteries (N = 5 per group) was reduced (P < or = 0.05) in tail suspended (TS, 511 +/- 47 microm, mean +/- SD) compared with cage sedentary (CS, 615 +/- 89 microm) and food restricted weight-paired (FR, 643 +/- 61 microm) groups. Neither hematocrit, red cell, plasma, nor total blood volume differed among groups. Following systemic vasodilation with papaverine, progressive arterial inflation with liquid silicon rubber (Microfil) revealed a reduction in both ED and distensibility of the femoral artery (P < or = 0.05). To determine the effects of tail suspension on systemic arterial morphology, the vasculature of additional rats was perfusion fixed at 80 mm Hg during vasodilation. Cross sections (thickness, 8 microm) of the carotid, axillary, iliac, and femoral arteries were then evaluated. Whereas the internal diameter of femoral arteries was smaller in TS than in CS (P < 0.05), no differences were observed for other vessels among groups. Further, arterial wall thickness increased systemically (overall, P < 0.05; carotid, 24%, P < 0.01; femoral, 28%, P < 0.01) following tail suspension. These findings illustrate adaptation in the structure of conduit arteries to prolonged tail suspension, with diameter altered regionally and wall thickness increased systemically. We suggest that chronic changes in activity patterns can influence arterial structure.

Analysis of Variance↗

Overview of the safety profile of clarithromycin suspension in pediatric patients.

Results of preclinical studies conducted to characterize the safety of clarithromycin oral suspension in juvenile mice, rats and dogs as compared with that in adult animals indicate that there is no enhanced risk in younger animals. Adverse events in these preclinical studies mainly involved decreased body and increased liver and kidney weights. The safety profile of clarithromycin suspension also has been evaluated in Phase II (pharmacokinetic) and III (clinical) United States and international clinical trials conducted in pediatric patients. The most frequently reported adverse events occurring among the 1676 patients studied who received clarithromycin suspension in Phase III trials included diarrhea (7%), vomiting (6%), abdominal pain (2%), headache (2%) and nausea (1%). Adverse events were not serious and were usually rapidly reversible. Adverse event rates did not vary with sex or race. Overall adverse event rates were generally similar to those of comparator beta-lactam suspensions (i.e. amoxicillin, amoxicillin/clavulanate, penicillin VK, cefaclor, cefadroxil). With regard to specific gastrointestinal events, however, clarithromycin was better tolerated than amoxicillin/clavulanate whereas penicillin VK showed a lower incidence of gastrointestinal events. Overall clarithromycin oral suspension appears to be safe and well-tolerated, making it suitable for use in the pediatric population.

Animals↗

Pharmacokinetics of ipriflavone and metabolites after oral administration of a corn-oil suspension relative to the Osteofix tablet.

Ipriflavone (IP) is a derivative of naturally occurring isoflavones and is marketed as Osteofix for the treatment of osteoporosis in Europe. IP has poor aqueous solubility, and the Osteofix compressed tablet has poor and variable bioavailability (F ). IP is incompletely absorbed after oral administration and is converted to five major metabolites (M1, M2, M3, M4, and M5). It is also further converted to metabolites M6 and M7 to a very small extent. The metabolites, especially M2 and M5, also have activity. A pilot study was conducted in healthy male volunteers that showed an 8- to 20-fold increase in the IP bioavailability after administration of Osteofix tablets in the fed state relative to the fasting state. A four-way crossover study was conducted in 16 healthy male volunteers, receiving Osteofix in fed state and 50, 100, and 200 mg of IP corn-oil suspension in fasted state. All IP administrations were safe and well tolerated. There was a reduction in the IP plasma level variability after 100-mg corn-oil administration as compared with that for the tablet. There was an increased relative F after the suspension, which was such that the 50-mg IP corn-oil suspension yielded similar levels as the 200-mg tablet. M5 was the major metabolite, consistent with earlier reports. The area under the curve to the last measured time point (AUC ( t ) ) levels were lower for M5, M3, and M2; higher for M1 and M2; and similar for IP after 50-mg corn-oil administration, as compared with the values for the tablet. This result may partially be explained by differences in the half-lives. Absorption/formation of M2 was delayed. The metabolite formation, except for M1 and M5, decreased with increased doses, which was accompanied by the prolonged half-life of IP and nonproportional increase in the IP AUC ( t ). This result may be due to autoinhibition of IP metabolism, because IP is an inhibitor of CYP3A4, and the metabolism of IP may be partly CYP3A4 mediated. Osteofix F may be improved by formulations that increase solubility, such as the corn-oil suspension. Although equivalent IP exposure from the tablet may be achieved at much lower overall doses because of the improved F by the corn-oil suspension, higher doses may require reconfirmation of safety and efficacy, given the differences in metabolic profiles obtained at higher doses.

Administration, Oral↗