Cephalosporin use in penicillin-allergic patients: a survey of otolaryngologists and literature review.
To compare the bioavailability of two risperidone orodispersible tablet products, Risperidone 1 mg Mouth dissolving tablet, Ranbaxy (Malaysia) Sdn. Bhd., Malaysia, as a test product and Risperdal 1 mg Quicklet, Janssen Ortho LLC, Gurabo, Puerto Rico, as a reference product, in healthy male volunteers under fasting condition.
Conduct disorder (CD) is one of the most common psychiatric disorders in childhood and adolescence. It is characterized by a variety of chronic antisocial behaviors, a repetitive and persistent pattern of behavior that violates the basic rights of others, major age-appropriate societal norms, or both. Aggressive behavior, lying, stealing, fire-setting, and running away from home and school are the most frequent manifestations of CD and are often accompanied by hyperactivity, impulsive behavior, explosiveness, cognitive and learning problems, and poor social skills. The rate of comorbidity is high, with attention-deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) being the most common; comorbid anxiety and depressive disorders are also seen, especially in adolescents. The diagnostic process should include the use of structured interviews, and scores from reliable and valid rating scales that cover all psychiatric disorders must be considered in the differential diagnosis, because CD alone is an extreme rarity and multiple disorders are almost always the rule rather than exception. Treatment should include parenting skills training combined with training of the child to improve his or her relationships with peers, academic performance, and compliance with legitimate demands of authority figures. The appropriate use of medications and integration of patient/parent education and support, as well as individual, group, family, residential, and inpatient treatment may be beneficial for patients with CD and ADHD. The article describes a number of psychopharmacological agents that are used in patients with CD with ADHD and other comorbid disorders. Drugs that may be useful include psychostimulants; atomoxetine (Strattera); antidepressants (imipramine [Tofranil], desipramine [Norpramin]); Selective Serotonin Reuptake Inhibitors (SSRIs); atypical antipsychotics such as risperidone (Risperdal); or mood regulators including lithium (Eskalith).
The main outcome measure was the disintegration and dissolution characteristics of the ODT formulations.
The liquid SELFs were designed using various oils, nonionic surfactants and converted into solid at various SELF: NUS2 (%m/m) mixing ratios. The characterization of solid SELF powder was performed by using SEM, XRD, FT-IR & DSC to investigate the physical nature of the drug. The in vitro dissolution experiments were conducted to compare the representative formulations with marketed product risperdal®. In vitro digestion experiments were performed using a pH-stat at pH 6.8 for 30mins to predict the fate of risperidone in the GI tract after exposure of the solid SELF to pancreatic enzymes and bile.
The purpose of this study was to develop a parenteral delivery system of Risperidone that would provide initial and extended drug release and thereby avoid the need for co-administration of oral tablets. Key formulation parameters utilized to achieve desired therapeutic levels in vivo were particle size and drug loading. Three poly (D,L-lactide-co-glycolide) (PLGA) microsphere formulations (Formulations A, B, and C) that encapsulated Risperidone were prepared by varying particle size (19-49 μm) and drug loading parameters (31-37%) but with a uniform bulk density (0.66-0.69)g/cc and internal porosity, utilizing the solvent extraction/evaporation method. The microspheres were characterized for drug content by HPLC, particle size by laser diffractometry, surface morphology by scanning electron microscopy (SEM), and in vivo drug release. In vivo studies were performed in male Sprague-Dawley rats, and levels of the active moiety (Risperidone and its metabolite, 9-hydroxyrisperidone) were assessed. In vivo release profiles from the three microsphere formulations were dependent on particle size and drug loading. The smaller sized microspheres (Formulation A) exhibited a large initial burst and a shorter duration of action, while the larger particles exhibited a smaller initial burst (Formulations B and C) but released drug for a much longer period in vivo. Extended duration of drug release was ascribed to higher drug content in the microspheres. A biweekly simulation of multiple dosing revealed that Formulation C, the selected formulation, with a high load and large particle size would provide adequate initial and maintenance levels of the active moiety (Risperidone and its metabolite, 9-hydroxyrisperidone). A comparison of biweekly dosing in vivo of Formulation C with the marketed product showed that at steady state, though average concentrations for both preparations were similar, the time taken to achieve steady state was much faster for Formulation C. The delay in attaining steady state with Risperdal Consta® was attributed to the 3 week latency in drug release from the microspheres and was in accordance with previous studies indicating a good corroboration with clinical findings. Calculated cumulative AUC (area under the curve) levels for Formulation C were similar to the Risperdal Consta®, though there were marked differences in AUC levels at the early time points. Comparison of Risperidal Consta® and Formulation C by multiple dosing in vivo experiments revealed that the marketed preparation demonstrated a substantial delay in providing an initial loading dose, continuous circulating levels, and attainment of steady state; all of which were observed rapidly with Formulation C. Findings from the current study strongly suggest that a microsphere dosage form of Risperidone can be formulated with an optimum particle size and drug loading to provide an initial bolus followed by maintenance levels, thereby eliminating combination therapy and improving patient compliance.