Immediate-release

Drug release should be controlled in accordance with the therapeutic purposes and pharmacological properties of the active substances. The plasma drug levels-time profiles after oral administration can be classified as rate ontrolled release and time-controlled release. Rate-controlled release is further classified into three types, i.e. immediate-release, prolonged-release, and modified-release. One typical time-controlled release is delayed-release. More advanced releases can be achieved by combinations of these different release types (Fig. 14.9). Various CyD derivatives have been used in order to modify drug releases in oral preparations [13, 15]. 

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The CO oxidation occurring in automobile exhaust converters is one of the best understood catalytic reactions, taking place on Pt surfaces by dissociative chemisoriDtion of to give O atoms and chemisoriDtion of CO, which reacts with chemisorbed O to give CO, which is immediately released into the gas phase. Details are evident from STM observations focused on the reaction between adsorbed O and adsorbed CO [12]. 

Common side effects of theophylline therapy include headache, dyspepsia, and nausea. More serious side effects such as lethal seizures or cardiac arrythmias can occur if blood levels are too high. Many derivatives of theophylline have been prepared in an effort to discover an analogue without these limitations (60,61). However, the most universal solution has resulted from the development of reHable sustained release formulations. This technology limits the peaks and valleys in semm blood levels that occur with frequent dosing of immediate release formulations. ControUed release addresses the problems inherent in a dmg which is rapidly metabolized but which is toxic at levels ( >20 7g/mL) that are only slightly higher than the therapeutically efficacious ones (10—20 p.g/mL). Furthermore, such once-a-day formulations taken just before bedtime have proven especially beneficial in the control of nocturnal asthma (27,50,62). 

Fig. 1. Zero-order (controlled) deflvery versus first-order (immediate-release) deflvery (repeated adrninistration). In 2ero-order deflvery, the dmg is released at a constant rate within the therapeutic range. In first-order deflvery, each administration of the dmg (represented by J.) causes semm-dmg concentrations...

Plasma dmg concentrations rise at a gradual, controlled rate after dosing, and reach a plateau at approximately 6 h after the first dose with minimal fluctuations over the 24 h dosing interval. Subsequent doses maintain the plasma concentration at this plateau. The extended release tablets taken once daily have reduced by fourfold the fluctuations (ratio of peak to trough plasma concentration) observed with the conventional immediate release Procardia tablets taken three times daily (81). 

Employees outside immediate release area who assist on-scene incident commander All activities coordinated through individual in charge of the incident command system Examples industrial hygienists or health physicists providing guidance on PPL selection Individuals likely to witness or discover a release and who are trained to initiate emergency response sequence... 

In 29 CER 1910.120 (a)(3) it is stated that responses to incidental releases of hazardous substances where the substance can be absorbed, neutralized, or otherwise controlled at the time of release by employees in the immediate release area, or by maintenance personnel, are not considered to be emergency responses in the scope of the standard (HAZWOPER). The term incidental is the key term. Workers need to be trained as to what type of situations would be considered incidental. In general, if the employees actions to clean or control the release do not and likely would not put them in jeopardy (from a safety and health viewpoint), the act would be considered incidental. 

When immediate-release products are used, die nurse administers die drug every 6 hours, hi some adults, intervals of 8 hours between dosing may be satisfactory. 

Withdraw the needle and immediately release the taut skin. 

The different salts, esters, ethers, isomers, mixtures of isomers, complexes or derivatives of an active substance shall be considered to be the same active substance, unless they differ significantly in properties with regard to safety and/or efficacy, in which case additional safety and efficacy data are required. The same qualitative and quantitative composition only applies to the active ingredients. Differences in excipients will be accepted unless there is concern that they may substantially alter the safety or efficacy. The same pharmaceutical form must take into account both the form in which it is presented and the form in which it is administered. Various immediate-release oral forms, which would include tablets, capsules, oral solutions and suspensions, shall be considered the same pharmaceutical form for this purpose. 

Laboratory experiments by our group showed that reaction 13 occurs very slowly in the gas phase (10). However, in the presence of ice surfaces the reaction proceeds very efficiently the product CI2 is immediately released to the gas phase, whereas HNO3 remains frozen in the ice (11). Other groups also found that this heterogeneous (i.e., multiphase) process occurs efficiently (12,13), and that a similar reaction also occurs with N2O5 as a reactant ... 

Tablet Formulations (Immediate Release). Two papers in the mid-1990s reported the earliest studies on immediate release tablets. In the first, tablet formulations of hydrochlorothiazide [33] were modeled in an attempt to maximize tablet strength and select the best lubricant. In the other, a tablet formulation of caffeine was modeled [34] to relate both formulation and processing variables with granule and tablet properties.

In a series of papers, personnel from Novartis and the University of Basel in Switzerland have highlighted the pros and cons of neural networks for immediate release tablets [37-40]. In other studies neural networks have been found useful in modeling tablet formulations of antacids [41], plant extracts [42], theophylline [43], and diltiazem [44]. In a recent paper Lindberg and Colbourn [45] have used neural networks, genetic algorithms, and neurofuzzy to successfully analyze historical data from three different immediate-release tablet formulations. 

To act as an efficient sterilizing agent, steam should be able to provide moisture and heat efficiently to the article to be sterilized. This is most effectively done using saturated steam, which is steam in thermal equilibrium with the water from which it is derived, i.e. steam on the phase boundary (Fig. 20.5). Under these circumstances, contact with a cooler surface causes condensation and contraction drawing in fresh steam and leading to the immediate release ofthe latent heat, which represents approximately 80% ofthe heat energy. In this way heat and moisture are imparted rapidly to articles being sterilized and dry porous loads are quickly penetrated by the steam. 

Reppas, C., Shah, V. P. Dissolution testing as a prognostic tool for oral drug absorption immediate release dosage forms. Pharm. Res. 1998, 15, 11-22. 

Do not combine with an antiplatelet agent o If patient experiences a systemic embolism while receiving warfarin and has a therapeutic INR, add aspirin 75-100 mg/d. For patients unable to take aspirin, then add dipyridamole 400 mg/d or clopidogel 75 mg/d. Immediate release dipyridamole needs an acidic gastric pH (<4) for adequate absorption... 

ER, extended-release FDA, Food and Drug Administration HDL, high-density lipoprotein IR, immediate-release LDL, low-density lipoprotein SR, sustained-release. 

Several different niacin formulations are available niacin immediate-release (IR), niacin sustained-release (SR), and niacin extended-release (ER).28,29 These formulations differ in terms of dissolution and absorption rates, metabolism, efficacy, and side effects. Limitations of niacin IR and SR are flushing and hepatotoxicity, respectively. These differences appear related to the dissolution and absorption rates of niacin formulations and its subsequent metabolism. Niacin IR is available by prescription (Niacor ) as well as a dietary supplement which is not regulated by the FDA.28 Currently, there are no FDA-approved niacin SR products, thus, all SR products are available only as dietary supplements. 

Sulfasalazine Azulfidine Azulfidine Entabs Sulfazine Sulfazine EC Immediate-release or enteric-coated tablets 500 mg 2-6 g Colon... 

Levodopa/Carbidopa (Sinemet ) Standard, immediate-release LD Sinemet CR Start with 1 tab (1 00 mg LD, 25 mg CD) two or three times daily ... 

The controlled-release (CR) formulation is more slowly absorbed and longer acting than immediate-release tablets. Patients need to increase the total daily dose by 30%, as it is not as bioavailable as the immediate-release levodopa/carbidopa. The CR formulation has a delayed onset (45 to 60 minutes) compared to the standard formulation (15 to 30 minutes). Thus, patients may also need to take immediate-release tablets or even a liquid formulation when they want a quicker onset of effect, such as with the first morning dose.1,8,25... 

Morning Sinemet dose should be immediate-release with or without CR... 

Galantamine is approved for the treatment of mild to moderate dementia of Alzheimer s disease. It can be dosed once or twice daily (if using the immediate-release tablet or extended-release capsule). The initial dose is 8 mg daily (or 4 mg twice daily) for 4 weeks. If tolerated the dose can be increased if needed to 16 mg daily (or 8 mg twice daily) for at... 

Bupropion causes insomnia, nightmares, decreased appetite, anxiety, and tremors, but the most concerning adverse effect is seizures. Because of the risk for seizures, patients who should not receive the drug include those with a CNS lesion or those with a history of seizures, head trauma, or bulimia. The daily dose of bupropion should not exceed 450 mg/day, and any single dose of the immediate-release formulation should not exceed 150 mg/day Occurrences of insomnia and/or nightmares often respond to moving the last daily dose from bedtime to late afternoon.7,9,22,23... 

Treatment of excessive daytime sleepiness in narcolepsy and other sleep disorders may require the use of sustained- and immediate-release stimulants to effectively promote wakefulness throughout the day and at key times that require alertness. 

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