Cholinergic Modulation of Narcoleptic Attacks in Double Orexin Receptor Knockout Mice

To investigate how cholinergic systems regulate aspects of the sleep disorder narcolepsy, we video-monitored mice lacking both orexin (hypocretin) receptors (double knockout; DKO mice) while pharmacologically altering cholinergic transmission. Spontaneous behavioral arrests in DKO mice were highly similar to those reported in orexin-deficient mice and were never observed in wild-type (WT) mice. A survival analysis revealed that arrest lifetimes were exponentially distributed indicating that random, Markovian processes determine arrest lifetime. Low doses (0.01, 0.03 mg/kg, IP), but not a high dose (0.08 mg/kg, IP) of the cholinesterase inhibitor physostigmine increased the number of arrests but did not alter arrest lifetimes. The muscarinic antagonist atropine (0.5 mg/kg, IP) decreased the number of arrests, also without altering arrest lifetimes. To determine if muscarinic transmission in pontine areas linked to REM sleep control also influences behavioral arrests, we microinjected neostigmine (50 nl, 62.5 µM) or neostigmine + atropine (62.5 µM and 111 µM respectively) into the nucleus pontis oralis and caudalis. Neostigmine increased the number of arrests in DKO mice without altering arrest lifetimes but did not provoke arrests in WT mice. Co-injection of atropine abolished this effect. Collectively, our findings establish that behavioral arrests in DKO mice are similar to those in orexin deficient mice and that arrests have exponentially distributed lifetimes. We also show, for the first time in a rodent narcolepsy model, that cholinergic systems can regulate arrest dynamics. Since perturbations of muscarinic transmission altered arrest frequency but not lifetime, our findings suggest cholinergic systems influence arrest initiation without influencing circuits that determine arrest duration

Oral Fast and Topical Controlled Ketoprofen Release Through Supercritical Fluids Based Processes

Ketoprofen (KET) is a non-steroidal anti-inflammatory drug (NSAID) widely used for different phlogistic diseases of rheumatoid and non-rheumatoid origin. When a fast release is required, KET is orally administered in form of capsules, tablets or granulates. In this case, due to KET poor solubility in water, large drug doses with consequent side effects, mainly gastrointestinal one are required. KET bioavailability can be enhanced through its coprecipitation with a hydrophilic carrier, such as polyvinylpyrrolidone (PVP). Another way to reduce the dosing frequency and avoid gastrointestinal irritation is the transdermal drug delivery with a controlled release. In this work, two different supercritical carbon dioxide (scCO2) based processes were used to modify KET dissolution rate: the supercritical antisolvent technique to coprecipitate PVP and KET in form of controlled dimensions microparticles for an oral delivery, and the supercritical adsorption to impregnate KET in alginate aerogel for a topical delivery. In the case of oral KET, composite spherical microparticles with controlled diameters were successfully produced, leading to a faster NSAID dissolution rate than unprocessed KET. In the case of topical KET, alginate aerogel was successfully impregnated with KET; it promotes a controlled release, suitable for transdermal anti-inflammatory patches, reducing frequency of administration and side effects. Supercritical techniques allow to obtain a fast or controlled release of the NSAID, according to the specific therapy desired