The Effect of Processing Variables on the Release of Ibuprofen and Caffeine from Controlled-Release Nonswellable Core-in-Cup Compressed Tablets

Hot-melt granulation in a twin screw extruder: effects of processing on formulations with caffeine and Ibuprofen

Hot-melt granulation (HMG) by twin screw extrusion is a novel technology for the continuous processing of pharmaceuticals but confidence must still be gained regarding whether the environment affects drug properties. In this preliminary study, granulation was studied for a model product containing lactose monohydrate and active ingredients of differing water solubility, namely ibuprofen versus caffeine. The formulations were granulated at 220 rpm and 100°C with polyethylene glycol binders of differing molecular weights and at concentrations between 6.5% and 20%. In terms of granule properties, the low melting point of ibuprofen had a dominant influence by producing larger, stronger granules, whereas the caffeine products were more comparable to a blank containing no active ingredient. Drug degradation was study by differential scanning calorimetry, X-ray diffraction, and high-pressure liquid chromatography. The only detected change was the dehydration of lactose monohydrate for the caffeine and blank products, whereas the lubricating influence of the ibuprofen protected its granules. The short residence time (∼60 s) was consider to be influential in minimizing damage of the drug despite the high temperature and shear attributed to HMG inside a twin screw extruder.

Zero-Order Release of Theophylline from a Core-in-Cup Tablet in Sequenced Simulated Gastric and Intestinal Fluid

Core-in-cup tablets containing theophylline were evaluated for their dissolution characteristics in sequenced simulated gastric fluid (SGF) followed by simulated intestinalfluid (SIF). Core-in-cup tablets containing 10% w/w, 20% w/w, and 30% w/w acacia as binder were evaluated for their effects on the time course of release of theophylline. This was done to optimize a formula that could release theophylline at a zero-order rate of release for 8-16 hr in simulated gastrointestinal fluids. Theophylline was released and dissolved from the core-in-cup tablets at a rate that is more consistent with a zero-order dissolution rate than a first-order dissolution rate in both SIG and SIF. The dissolution rates of theophylline from the 10%, 20%, and 30% acacia core-in-cup tablets were 0.87 mg/min, 0.53 mg/min, and 0.27 mg/min, respectively in SGF, and 0.61 mg/min, 0.30 mg/min, and 0.20 mg/min, respectively in SIF. The results indicate that a concentration of 32% w/w acacia in the core tablet will release theophylline at a rate of 0.14 mg/min in SGF for 2 hr followed by SIF for 10 hr.

A novel compression-coated doughnut-shaped tablet design for zero-order sustained release

A novel coated doughnut-shaped tablet is evaluated as to its ability to be manufactured in a reproducible manner, and as to whether it releases model drugs at a zero-order rate. The doughnut-shaped tablets were compressed using specially designed punches, which make automated production feasible. In the preliminary part of the experiment, HPMC K15M mixed with gelatin was found to be the most suitable coating tablet material with respect to its disintegration and adherence properties. The adherence of the coating tablet to ibuprofen cores was not optimal, so different concentrations of gelatin, to act as a plasticiser and enhance adherence, were further investigated. Friability results of the coated doughnut-shaped tablet indicate that coating tablets containing 20% and 30% gelatin had a percentage weight losses of less than 1% after 100 revolutions in a Roche friabilator. For all the concentrations of gelatin, the granule blends had angle of repose values in the range of 22.01-17.8 degrees. The compressibility factor, as measured from the slopes of the natural logarithm of compressional force versus crushing strength, were 121.91 +/- 2.36, 132.64 +/- 3.60, and 88.54 +/- 11.52 for the coating tablet granules containing 10%, 20%, and 30% gelatin in HPMC K15M, respectively. The composition of the coating tablet did not affect the rate of release of both caffeine and ibuprofen from the coated doughnut-shaped tablets. The coatings also adhered to the core tablets for the entire duration of the release of the drugs.

Optimization and development of a core-in-cup tablet for modulated release of theophylline in simulated gastrointestinal fluids

A triple-layer core-in-cup tablet that can release theophylline in simulated gastrointestinal (GI) fluids at three distinct rates has been developed. The first layer is an immediate-release layer; the second layer is a sustained-release layer; and the last layer is a boost layer, which was designed to coincide with a higher nocturnal dose of theophylline. The study consisted of two stages. The first stage optimized the sustained-release layer of the tablet to release theophylline over a period of 12 hr. Results from this stage indicated that 30% w/w acacia gum was the best polymer and concentration to use when compressed to a hardness of 50 N/m2. The second stage of the study involved the investigation of the final triple-layer core-in-cup tablet to release theophylline at three different rates in simulated GI fluids. The triple-layer modulated core-in-cup tablet successfully released drug in simulated fluids at an initial rate of 40 mg/min, followed by a rate of 0.4085 mg/min, in simulated gastric fluid TS, 0.1860 mg/min in simulated intestinal fluid TS, and finally by a boosted rate of 0.6952 mg/min.

New controlled-release ibuprofen tablets

Tablets containing two different doses of ibuprofen are realized. The first possesses very fast release kinetics, while the second has slow and linear release kinetics. This allows drug to produce a therapeutic effect quickly and to maintain it for a long time with only one administration unit. Such tablets are obtained by compression of a mixture of two very different kinds of granulates: an ibuprofen-starch granulate and an ibuprofen-Eudragit RS microsphere granulate. Specific proportions of mixtures of them give the described result after compression at particular tablet hardnesses.