By a News Reporter-Staff News Editor at Drug Week A patent application by the inventor Venkatesh, Gopi M. (Vandalia, OH), filed on January 9, 2017, was made available online on May 4, 2017, according to news reporting originating from Washington, D.C., by NewsRx correspondents (see also Adare Pharmaceuticals, Inc.).
This patent application is assigned to Adare Pharmaceuticals, Inc.
The following quote was obtained by the news editors from the background information supplied by the inventors: "Many therapeutic agents are most effective when made available at constant rates at or near the absorption sites. The absorption of therapeutic agents thus made available generally results in desired plasma concentrations leading to maximum efficacy, and minimum toxic side effects. Much effort has been devoted to developing sophisticated drug delivery systems such as osmotic devices for oral application. However, there are instances where maintaining a constant blood level of a drug is not desirable. For example, a major objective of chronotherapy for cardiovascular diseases is to deliver the drug in higher concentrations during the time of greatest need, e.g., the early morning hours, and in lesser concentrations when the need is less, e.g., during the late evening and early sleep hours. In addition to a properly designed drug delivery system, the time of administration is equally important. The unique pharmacokinetic profile needed can be calculated from a simulated modeling developed using the pharmacokinetic parameters, knowledge of drug solubility, absorption along the gastrointestinal tract and elimination half-life.
"A timed, pulsatile delivery system capable of providing one or more immediate release pulses at predetermined lag times or at specific sites result in better absorption of the active and more effective plasma profile. However, there are only a few such orally applicable pulsatile release systems due to potential limitations of the dosage form size, and/or polymeric materials and their compositions used for producing dosage forms. Ishino et al. disclose a dry-coated tablet form in Chemical Pharm. Bull. Vol. 40 (11), p 3036-3041 (1992). U.S. Pat. No. 4,871,549 assigned to Fujisawa Pharmaceutical Company discloses the preparation of a time-controlled explosion system in which rapid-release pulses at predetermined time intervals are caused by explosion of the membrane surrounding the drug cores comprising swelling agents such as disintegrants (e.g., low-substituted hydroxypropylcellulose, crospovidone, crosslinked carboxymethylcellulose, sodium starch glycolate). These systems are rather difficult to manufacture and do not consistently perform.
"U.S. Pat. No. 6,531,152 discloses an explosion-controlled drug delivery system comprising a core containing a drug in combination with a core material (such as a polysaccharide or a crosslinked protein and a disintegrant that swell on exposure to body fluids or water) having a rigid membrane comprising hydrophobic and hydrophilic polymers that bursts rapidly releasing the active when the core swells. The '152 patent discloses specific tablet formulations having lag-times of up to about 12 hours. U.S. Pat. No. 6,287,599 to Burnside et al. discloses a pharmaceutical composition (a tablet formulation) comprising at least one pharmaceutically active agent that has a pH dependent solubility, at least one non-pH dependent sustained release agent and at least one pH-dependent agent that increases the dissolution rate of the active at a pH in excess of 5.5. Such a system exhibits approximately pH independent drug release profile.
"However, monolithic drug delivery systems exhibit variable gastrointestinal transit times, and multiparticulate dosage forms containing coated drug particles (beads, pellets or micro-tablets) exhibiting consistent GI transit times are preferred.
"The pulsatile burst release times in the above-described delivery systems are controlled by choosing appropriate core material, and by varying the membrane composition and/or thickness. However, it is difficult to consistently manufacture quality products based on such drug delivery systems wherein the drug-release is controlled by a swelling agent, a hydrophobic excipient, an osmotic agent alone or mixtures thereof.
"U.S. Pat. No. 6,627,223, assigned to Eurand Pharmaceutical Limited, which is incorporated herein by reference, discloses a pulsatile release system consisting of a combination of one or more bead populations, each with a well-defined release profile. A timed, sustained-release profile (i.e., a sustained-release profile over a 12 to 24 hours after a lag-time of about 4 hours (i.e., a period of little or no release) following oral administration is disclosed in U.S. Pat. No. 6,500,454, and a biphasic release profile (i.e., an immediate-release pulse and a rapid burst after a lag-time of about 3 hours) is disclosed in U.S. Pat. No. 6,663,888. Although, a lag-time of greater than 3 hours could be achieved by applying a membrane comprising a water-insoluble polymer such as ethylcellulose (Ethocel Standard Premium 10 cps available from Dow Chemical Company) and an enteric polymer such as hydroxypropyl methylcellulose phthalate (HP-55 available from Shin-Etsu Chemical Corporation, Tokyo, Japan) on drug-layered beads containing propranolol hydrochloride (56% drug-load coated on 25-30 mesh sugar spheres) at 10-15% weight gain, the same coating composition applied on drug-layered beads containing nizatidine (56% drug-load coated on 25-30 mesh sugar spheres) even at 35-39% by weight resulted in a lag-time of less than 3 hours. It was considered in the prior art that the solubility of therapeutic agent in the dissolution medium and/or the molecular weight of the agent determined the drug dissolution within the coated bead and its diffusion out of the membrane. After extensive investigations, it was surprisingly discovered that apart from pH-dependent solubility of the therapeutic agent, its acidity/alkalinity has a significant effect on the lag-time that could be achieved. Additionally, the impact of a barrier coating (i.e., an intermediate coating applied in between the inner protective seal coat and the outer lag time coating, hereafter referred to as the barrier coat) and/or its composition on lag-time that could be achieved can vary depending on the acidity/alkalinity of the actives."
In addition to the background information obtained for this patent application, NewsRx journalists also obtained the inventor's summary information for this patent application: "The present invention provides a pulsatile delivery system suitable for a twice-daily or once-daily dosing regimen by oral administration of a specific therapeutic agent depending on its acidity/alkalinity, solubility in gastrointestinal fluids, and its elimination half-life. The pulsatile delivery system comprises one or more bead populations, such as immediate release (IR) Beads and timed, pulsatile-release (TPR) bead populations. Each TPR bead population releases the drug as a rapid burst or as a sustained-release profile after a pre-determined lag-time (for example, 10 hours or longer is achievable) upon oral administration. The IR Beads may be simply drug cores coated with a protective membrane (for example, a coating with Opadry Clear). These IR Beads with a barrier coating are coated with a functional membrane of a mixture of water insoluble and enteric polymers, a plasticized polymeric system being applied from aqueous or solvent based composition. The finished dosage form may be a modified-release (MR) capsule, a standard (conventional) tablet or an orally disintegrating tablet (ODT) comprising a coated spherical bead population containing the active substance alone or a combination of two or more coated bead populations to provide target plasma concentrations suitable for a once or twice-daily dosing regimen. For example, a once-daily dosage form of an active with an elimination half-life of about 7 hours may contain a mixture of an IR bead population which allows immediate release, a second, TPR bead population with a shorter lag-time (about 3-4 hours), which allows a delayed 'burst' release and a third, TPR bead population with a longer lag-time (about 6-9 hours), which allows a delayed, typically sustained-release profile of an active with an elimination half-life of about 7 hours, thus enhancing safety, therapeutic efficacy and patient compliance while reducing cost of treatment. The achievable lag time depends on the composition and thickness of the barrier coating, the composition and thickness of the lag-time coating, as well as the nature of the therapeutic agent. Specific factors that can affect the lag-time include, but are not limited to, the therapeutic agent's alkalinity/acidity, solubility, elimination half-life, and dosing (twice-daily or once-daily) regimen."
URL and more information on this patent application, see: Venkatesh, Gopi M. Timed, Pulsatile Release Systems. Filed January 9, 2017 and posted May 4, 2017. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220170112774%22.PGNR.&OS=DN/20170112774&RS=DN/20170112774
Keywords for this news article include: Adare Pharmaceuticals Inc., Dosage Forms, Drugs and Therapies, Drug Delivery Systems.
Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2017, NewsRx LLC