Controlled release products

U. Gundert-Remy and H. Mufler, eds.. Oral Controlled Release Products Therapeutic and Biopharmaceutic Assessment, Wissenschafdiche VedagsgeseUschaft mbH, Stuttgart, Germany, 1990. 

Diethylpropion is available as both an immediate-release and a controlled-release product. In conjunction with a reduced-calorie diet and/or exercise, dose diethylpropion (immediate-release) 25 mg three times a day before meals or 75 mg (controlled-release) once a day, usually midmorning.40... 

Traditionally, the ideal extended-release product has been conceived as providing essentially stable blood levels over the whole dosing frequency interval. Thus, unlike the saw-edge blood concentration time profile of a non-controlled-release product that may show rather wild fluctuations between sub- and su-pratherapeutic blood levels, the ideal extended-release product avoids both nontherapeutic blood levels and those likely to have an increased frequency of dose-related side effects. However, in recent years con-trolled-release products that deliberately exploit a pulsatile drug release time profile have also attracted attention. 

Rapid-release products are another class of con-trolled-release drug-delivery systems of growing interest to pharmaceutical scientists. For this type of product rapidity of response is the key parameter. If a conventional non-controlled-release product gives the therapeutic response in one hour, a rapid-release product might be designed so as to yield such a response in 20 minutes. 

Even the most superficial evaluation of bioequivalency requirements for controlled-release products will indicate that for some of these products, at least, the conventional AUC, Tmax, and Cmax measures of bioequivalency may well be insufficient. Thus, for a non-pulsatile sustained-release product with a dosing interval of 24 hours (as compared to 4 hours for the noncontrolled product), the time period during which plasma concentrations are maintained at essentially a plateau level might well be regarded as of critical... 

The topic of bioequivalency tests for controlled-release products has attracted comment from a number of groups. For example, Bialer and co-workers [4] have proposed four new parameters ... 

M. Bialer, L. Arcavi, S. Sussan, A. Volosov, A. Yacobi, D. Morus, B. Levitt, and A. Laor, Existing and new criteria for bioequivalence evaluation of new controlled release products of carbamazipine, Epilepsy Res., 32, 371 (1998). 

Mehta, A. M., Scale-Up Considerations in the Fluid-Bed Process for Controlled Release Products, Pharm. Tech., 12 46-52(1988)... 

Use immediate-release productwilh controlled-release product to control "breakthrough" pain in cancer or chronic pain patients Use in severe pain Oral not recommended Do not use in renal failure May precipitate tremors, myoclonus, and seizures... 

In general, the intestinal perfusion technique has proved a powerful research tool, despite these shortcomings. Its primary application has been in the estimation of Peft the model also lends itself to comparing permeability differences from one site to another along the intestine, an essential prerequisite for accurately classifying controlled release products [59]. Cross-over experiments tend... 

Sonication using ultrasonic cleaner baths remains a popular extraction approach particularly for controlled-release products. In sonication, an ultrasonic wave of 20-40 kHz generated by a piezoelectric transducer is used to produce the formation and collapse of thousands of microscopic bubbles (cavitations) in the water bath to facilitate the break up of the solid particles and the subsequent dissolution of the API. Note that parameters such as the wattage power of the sonicator, presence of the perforated tray, depth of the water level, bath temperature and the number of sample flasks sonicated might all affect the extraction rate. For... 

Tarvainen, M., Peltonen, S., Mikkonen, H., Elovaara, M., Tuunainen, M., Paronen, P, Ketolainen, J., Sutinen, R. (2004). Aqueous starch acetate dispersion as a novel coating material for controlled release products. J. Contr. Re/., 96(1), 179-191. 

For dissolution testing, a normal range is +20% over the specified range. If the acceptance criterion for a controlled-release product covers a region from 20% after... 

Materials used in controlled release products. Following is a list of the most commonly used water-soluble polymers and plasticizers for controlled release coating, as well as a description of their properties. This list is not meant to be comprehensive of all materials ever proposed for use in such products. 

Many commercial controlled-release products are based on both diffusion and degradation mechanisms (14). Such... 

Modified-Release Products. Modified-release products include delayed-release products and extended (controlled)-release products. 

For example, a 505(b)(2) application would be appropriate for a controlled release product that is bioinequivalent to a reference listed drug where... 

Over the years, many types of such controlled-release formulations have been evaluated, such as cotton wicks, rubber septa, polyethylene in various forms, cigarette filters, plastic tablets, cork, wax, molecular sieve, etc. (2). In recent years, commercial production of controlled-release formulations has provided an economical and reproducible source of pheromone dispensers and small particles for aerial dispersion. At the present time, many of the insect pheromone programs involving commercially produced, controlled-release products use one of the formulations listed in Table I. 

Rathbone, M. J, Macmillan, K. L., JoChle, W., Boland, M., and Inskeep, E. K. (1998), Controlled release products for the control of the estrous cycle in cattle, sheep, goats, deer, pigs, and horses, Crit. Rev. Ther. Drug Carrier Syst., 15, 285-380. 

Malinowski, H. I, and Marroum, P. J. (1999), Encyclopedia of Controlled Drug Delivery, vols. 1 and 2, Food and Drug Administration Requirements for Controlled Release Products, John Wiley Sons, New York, vol. 1, pp. 381-395. 

Controlled-release product available 240 mg once daily (60-mg immediate-release with 180-mgcontrolled-release),... 

Assay (dissolution) +30% of specified range (for immediate release dosage form). If the specification for a controlled release product (modified release or sustained release) covers a region from 20% (after 1 hr) to 90% (after 24 hr), the validated range would cover 50% of 1-hr limit (20% x 50% = 10%) to 130% of the label claim (label claim x 1.3). 

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