Release, drug formulation

Bailey DG, Arnold JM, Bend JR, Tran LT, Spence JD. Grapefruit juice-felodipine interaction reproducibility and characterization with the extended release drug formulation. Br J Clin Pharmacol 1995 40(2) 135-140. 

Roston, D.A. Sun, J.J. Collins, P.W. Perkins, W.E. Tremont, S.J. Supercritical fluid extraction-liquid chromatography method development for a polymeric controlled-release drug formulation. J. Pharm. Biomed. Anal. 1995, 13 (12), 1513-1520. 

Mueller, B. Fisher, W. Manufacture of Sterile Sustained Release Drug Formulations Using Liquefied Gases, 1989. DE 3744329 Germany (West). 

Barthelemy, P. Laforet, J.P. Farah, N. Joachim, J. Compritol 888 ATO an innovative hot-melt coating agent for prolonged-release drug formulations. E. J. Pharm. Bio-pharm 1999, 47, 87-90. 

Mueller BW, Fisher W. Manufacture of sterile sustained release drug formulations using liquefied gases. (West) Germany, DE 3744329, 1989. 

Controlled-release drug formulation Dried blood... 

Many industrial materials today are composed of a coating of one material on a second material. Toner particles for copy machines are one example coated time-release drug formulations are another example. The DP 1000 easily distinguishes coated particles... 

Miscibility of Polymers in Binary Fluid Mixtures. Cellulose Derivatives. Miscibility of cellulose derivatives in binary fluid mixtures of carbon dioxide is of recent interest because of the significance of these polymers in controlled-release drug formulations, and also because of the traditional significance of cellulose based polymers as film or fiber... 

Details are given of the synthesis of a new family of ether-anhydride copolymers for use in controlled release drug formulations for inhalation. Microparticles containing model drugs were made with sizes suitable for deposition in various regions of the lung following inhalation as a dry powder. 50 refs. 

As pharmaceutical scientists gain experience and tackle the primary challenges of developing stable parenteral formulations of proteins, the horizons continue to expand and novel delivery systems and alternative routes of administration are being sought. The interest in protein drug delivery is reflected by the wealth of literature that covers this topic [150-154]. Typically, protein therapeutics are prepared as sterile products for parenteral administration, but in the past several years, there has been increased interest in pulmonary, oral, transdermal, and controlled-release injectable formulations and many advances have been made. Some of the more promising recent developments are summarized in this section. 

Mechanisms of dissolution kinetics of crystals have been intensively studied in the pharmaceutical domain, because the rate of dissolution affects the bioavailability of drug crystals. Many efforts have been made to describe the crystal dissolution behavior. A variety of empirical or semi-empirical models have been used to describe drug dissolution or release from formulations [1-6]. Noyes and Whitney published the first quantitative study of the dissolution process in 1897 [7]. They found that the dissolution process is diffusion controlled and involves no chemical reaction. The Noyes-Whitney equation simply states that the dissolution rate is directly proportional to the difference between the solubility and the solution concentration ... 

Recently, Yoshikawa et al. [70] reported a new in vitro dissolution test, called the rotating beads method, for drugs formulated in pressure-controlled colon delivery capsules. This dissolution method was applied to acetominophen sustained-release tablets and two other drugs having low solubility in the colon, tegafur and 5-ASA. There was good correlation between the in vitro dissolution rates and the in vivo absorption rates. 

Another strategy rehes on the strong peristaltic waves in the colon that lead to a temporarily increased luminal pressure (pressure-controlled drug release). Pressure-sensitive drug formulations release the drug as soon as a certain pressure limit is attained, i.e. destruction force is exceeded. 

As mentioned before, nifedipine was the first marketed dihydropyridine CCB. Initially, the drug indication was exclusively for angina, but the more recently developed extended release (ER) formulations are used off-label primarily for hypertension (Bayer, 2004). The extended-release tablets use a cellulose coat that extends their release time. The half-life of the ER formulation is reported as 7 h, whereas the immediate-release formulation has a half-life of 2 h (Bayer). 

---