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Background: Poor oral absorption of budesonide limits the design of its solid oral dosage form. With this context, multiparticulate pulsatile system of budesonide for chronotherapy of nocturnal asthma was aimed in this study. Methods: Initially, solid dispersions of budesonide (BD) using sodium starch glycolate (SSG) and guar gum (GG) were developed and characterized. Uniform sized non-pareil seeds (~400 μm) were coated with solid dispersions to obtain immediate (BMP) and controlled release pellets by solution layering technique. Rationale of selection of BD in this research was based on recent patents such as diltiazem HCl (US5914134) and multipar-ticulate systems (US5017381). Pulsatile drug release pellets (BMPP) of BD were obtained by coating the controlled release pellets with Eudragit L100 and RS 100. Pellets were assessed by saturation sol-ubility, FTIR, DSC, micromeritic, SEM, drug content, drug release, pharmacokinetic and stability studies. Results: Solubility of BD was increased by 22 folds due to inter-particle distribution of BD and polymers in solid dispersions. No changes in characteristic functional groups of BD had indicated the compatibility of drug with polymers as noticed in FTIR and DSC. Fluidized bed processor enabled the production of spherical and uniformly distributed pellets with optimum angle of repose (12-19°) and friability (<1%). Solution layering technique employed in preparation of pellets had facilitated with moderately high BD content (91.5-99.6%) and 100% drug release at the end of 12hr. The pulsatile release pellets (BMPP) produced 6hr lag phase followed by 12hr controlled release. Promised pharmacokinetics was resulted as Cmaxof 380ng/ml for BMP-2 and 162ng/ml for BMPP-5 and Tmaxof 5 hr for BMP-2 and 12hr for BMPP-5. Increased pharmacokinetics was the direct results of increased solubility of BD due to application of solid dispersion and solution layering on pellets. Conclusions: Chronopharmacokinetics of BD were achieved with the help of Eudragit coatings on pellets. The BMP and BMPP formulations were found to be reasonably stable over a period of time. Thus, optimal chronopharmacokinetics of BD was achieved successfully by multiparticulate pulsatile technology.

We investigated the in vivo role of protein degradation during intermediate (ITM) and long-term memory (LTM) in Aplysiausing an operant learning paradigm. The proteasome inhibitor MG-132 inhibited the induction and molecular consolidation of LTM with no effect on ITM. Remarkably, maintenance of steady-state protein levels through inhibition of protein synthesis using either anisomycin or rapamycin in conjunction with proteasome inhibition permitted the formation of robust 24 h LTM. Our studies suggest a primary role for proteasomal activity in facilitation of gene transcription for LTM and raise the possibility that synaptic mechanisms are sufficient to sustain 24 h memory.

Insufficient sleep in individuals appears increasingly common due to the demands of modern work schedules and technology use. Consequently, there is a growing need to understand the interactions between sleep deprivation and memory. The current study determined the effects of acute sleep deprivation on short and long-term associative memory using the marine mollusk Aplysia californica, a relatively simple model system well known for studies of learning and memory.

Circadian clocks evolved under conditions of environmental variation, primarily alternating light dark cycles, to enable organisms to anticipate daily environmental events and coordinate metabolic, physiological, and behavioral activities. However, modern lifestyle and advances in technology have increased the percentage of individuals working in phases misaligned with natural circadian activity rhythms. Endogenous circadian oscillators modulate alertness, the acquisition of learning, memory formation, and the recall of memory with examples of circadian modulation of memory observed across phyla from invertebrates to humans. Cognitive performance and memory are significantly diminished when occurring out of phase with natural circadian rhythms. Disruptions in circadian regulation can lead to impairment in the formation of memories and manifestation of other cognitive deficits. This review explores the types of interactions through which the circadian clock modulates cognition, highlights recent progress in identifying mechanistic interactions between the circadian system and the processes involved in memory formation, and outlines methods used to remediate circadian perturbations and reinforce circadian adaptation.

To characterize sleep in the marine mollusk, Aplysia californica.