Showing papers in "Recent Patents on Drug Delivery & Formulation in 2009"

CNS Drug Delivery Systems: Novel Approaches

Abstract: The brain is a delicate organ, and nature has very efficiently protected it. The brain is shielded against potentially toxic substances by the presence of two barrier systems: the blood brain barrier (BBB) and the blood cerebrospinal fluid barrier (BCSFB). Unfortunately, the same mechanisms that protect it against intrusive chemicals can also frustrate therapeutic interventions. Despite aggressive research, patients suffering from fatal and/or debilitating central nervous system (CNS) diseases, such as brain tumours, HIV encephalopathy, epilepsy, cerebrovascular diseases and neurodegenerative disorders, far outnumber those dying of all types of systemic cancers or heart diseases. The abysmally low number of potential therapeutics reaching commercial success is primarily due to the complexity of the CNS drug development. The clinical failure of many probable candidates is often, ascribable to poor delivery methods which do not pervade the unyielding BBB. It restricts the passive diffusion of many drugs into the brain and constitutes a significant obstacle in the pharmacological treatment of central nervous system (CNS) disorders. General methods that can enhance drug delivery to the brain are, therefore, of great pharmaceutical interest. Various strategies like non-invasive methods, including drug manipulation encompassing transformation into lipophilic analogues, prodrugs, chemical drug delivery, carrier-mediated drug delivery, receptor/vector mediated drug delivery and intranasal drug delivery, which exploits the olfactory and trigeminal neuronal pathways to deliver drugs to the brain, are widely used. On the other hand the invasive methods which primarily rely on disruption of the BBB integrity by osmotic or biochemical means, or direct intracranial drug delivery by intracerebroventricular, intracerebral or intrathecal administration after creating reversible openings in the head, are recognised. Extensive review pertaining specifically, to the patents relating to drug delivery across the CNS is currently available. However, many patents e.g. US63722506, US2002183683 etc., have been mentioned in a few articles. It is the objective of this article to expansively review drug delivery systems for CNS by discussing the recent patents available.

Trends in Pharmaceutical Taste Masking Technologies: A Patent Review

Abstract: According to the year 2003 survey of pediatricians by the American Association of Pediatrics, unpleasant taste was the biggest barrier for completing treatment in pediatrics. The field of taste masking of active pharmaceutical ingredients (API) has been continuously evolving with varied technologies and new excipients. The article reviews the trends in taste masking technologies by studying the current state of the art patent database for the span of year 1997 to 2007. The worldwide database of European patent office (http://ep.espacenet.com) was employed to collect the patents and patent applications. It also discusses the possible reasons for the change of preferences in the taste masking technologies with time. The prime factors critical to the selection of an optimal taste masking technique such as the extent of drug bitterness, solubility, particle characteristics, dosage form and dose are briefly discussed.

Mucoadhesive Vaginal Drug Delivery Systems

Abstract: Vaginal delivery is an important route of drug administration for both local and systemic diseases. The vaginal route has some advantages due to its large surface area, rich blood supply, avoidance of the first-pass effect, relatively high permeability to many drugs and self-insertion. The traditional commercial preparations, such as creams, foams, gels, irrigations and tablets, are known to reside in the vaginal cavity for a relatively short period of time owing to the self-cleaning action of the vaginal tract, and often require multiple daily doses to ensure the desired therapeutic effect. The vaginal route appears to be highly appropriate for bioadhesive drug delivery systems in order to retain drugs for treating largely local conditions, or for use in contraception. In particular, protection against sexually-transmitted diseases is critical. To prolong the residence time in the vaginal cavity, bioadhesive therapeutic systems have been developed in the form of semi-solid and solid dosage forms. The most commonly used mucoadhesive polymers that are capable of forming hydrogels are synthetic polyacrylates, polycarbophil, chitosan, cellulose derivatives (hydroxyethycellulose, hydroxy-propylcellulose and hydroxypropylmethylcellulose), hyaluronic acid derivatives, pectin, tragacanth, carrageenan and sodium alginate. The present article is a comprehensive review of the patents related to mucoadhesive vaginal drug delivery systems.

Recent Trends in Oral Drug Delivery: A Review

Abstract: There are many ways to deliver drugs into the body, viz oral (through swallowing), sub mucosal (through buccal and sublingual mucosa), parenteral (through injection), transdermal (through skin), pulmonary (through inhalation) etc. Among these deliveries oral delivery (by swallowing) is widely accepted. In oral drug delivery, many scientific challenges and breakthrough technologies are required to generate novel dosage forms raising drug delivery to higher level. Some are self emulsifying systems, solid self nanoemulsion, polymeric micelles, spray freezing, pH controlled systems, time delayed system, osmotic pumps, prodrugs etc. This paper reviews recent patents, technologies and products with their importance, manufacturing and novel approaches implemented till date to overcome the challenges in oral drug delivery systems.

Chitosan and its use in design of insulin delivery system.

Abstract: The global burden of diabetes is estimated to escalate from about 171 million in 2000 to 366 million people in 2030. The routine of diabetes treatment by injection of insulin incurs pain and has been one major factor negating the quality of life of diabetic patients. The possibility of administering insulin via alternative routes such as oral and nasal pathways has been investigated over the years, but with insulin experiencing risks of enzymatic degradation and poor transmucosal absorption. This leads to the rising needs to develop new formulation strategies emphasizing on the assembly of insulin and excipients into a physical structure to maintain the stability and increase the bioavailability of insulin. Chitosan and its derivatives or salts have been widely investigated as functional excipients of delivering insulin via oral, nasal and transdermal routes. The overview of various recent patented strategies on non-injection insulin delivery denotes the significance of chitosan for its mucoadhesive and able to protect the insulin from enzymatic degradation, prolong the retention time of insulin, as well as, open the inter-epithelial tight junction to facilitate systemic insulin transport. The chitosan can be employed to strengthen the physicochemical stability of insulin and multi-particulate matrix. The introduction of chitosan coat or co-formulation of chitosan with cationic gelatin or electrolytes which provide solidified or partially crosslinked structures retain and/or enhance the positive charges of dosage form necessary to induce mucoadhesiveness. The chitosan is modifiable chemically to produce water-soluble low molecular weight polymer which renders insulin able to be processed under mild conditions, and sulphated chitosan which markedly opens the paracellular channels for insulin transport. Combination of chitosan and fatty acid as hydrophobic nanoparticles promotes the insulin absorption via lymphoid tissue. Attainment of optimized formulations with higher levels of pharmacological bioavailability is deemed possible in future through targeted delivery of insulin using chitosan with specific adhesiveness to the intended absorption mucosa.

Enhanced transdermal drug delivery techniques: an extensive review of patents.

Abstract: Transdermal drug delivery system has been accepted as potential non-invasive route of drug administration, with advantages of avoidance of the first-pass metabolism, sustained therapeutic action and better patient compliance, though, its prevalent use is restricted due to excellent impervious nature of skin. It is the greatest challenge for researchers to surmount the inherent limitations imposed by stratum corneum of skin, for enhanced transdermal drug delivery to achieve systemic therapeutic concentration. Thus, many approaches have been attempted to perturb skin barrier and enhance the transdermal delivery of drug. The major approaches for enhancing transdermal delivery are physical enhancers (ultrasound, iontophoresis, electroporation, magnetophoresis, microneedle), vesicles, particulate systems (liposome, niosome, transfersome, microemulsion, solid lipid nanoparticle) and chemical enhancers (sulphoxides, azones, glycols, alkanols, terpenes etc.). The present review explores recent patents on techniques employed to breach the skin barrier for drug permeation along with their penetration enhancement mechanisms.

New Generation of Liposomes Called Archaeosomes Based on Natural or Synthetic Archaeal Lipids as Innovative Formulations for Drug Delivery

Abstract: Archaeosomes made from natural archaeal membrane lipids and/or synthetic lipid analogues have been extensively studied for potential applications in drug and vaccine delivery over the past decade only. Archaeal-type lipids consist of archaeol (diether) and/or caldarchaeol (tetraether) core structures wherein regularly branched and usually fully saturated phytanyl chains (20-40 carbons in lengths), are attached via ether bonds to the sn-2,3 carbons of the glycerol backbone. Archaeosomes constitute a novel generation of liposomes that exhibit high stabilities to low or high temperatures, acidic or alkaline pH, oxidative conditions, high pressure, action of phospholipases, bile salts and serum proteins. These properties associated with a good safety profile are beneficial for nanotechnological applications in drug and gene delivery. Additionally, archaeosome formulations could be used as efficient carriers of antigens and/or adjuvants promoting antigen-specific, humoral and cell-mediated immune responses, in addition to antigen-specific mucosal immune responses in the vaccinated hosts. The immune responses are well sustained over time, and are subject to strong memory responses. Nanodelivery-based vaccinations using archaeosomes could then represent a promising approach for treating and preventing infections, allergies, and neoplastic or cancer diseases. In this review, the few recent US, World and European patents developing archaeosomes for these biotechnological applications in Health are discussed.

Smart Polymers for Controlled Delivery of Proteins and Peptides: A Review of Patents

Abstract: Protein and peptide-based therapeutic agents have unique physiochemical properties such as high molecular weight, short half life, requirement of a sustained plasma level for the desired therapeutic effect, liable to physical and chemical instability by gastric enzymes and harsh acidic environment as well as first pass metabolism, which makes their delivery a challenge. The delivery of proteins and peptides using various routes of administration like oral, nasal, rectal, pulmonary, buccal, vaginal and transdermal route is found to exhibit limitations, poor permeability and degradation being major limitations. Use of parenteral route is found to overcome these problems but patient compliance is poor due to the need for frequent administration. Use of control delivery for these drugs using smart polymers seems promising as they overcome the limitations posed by other routes of delivery. Smart polymers increase patient compliance, maintain stability of the drug, and maintain drug level in therapeutic window and are easy to manufacture. Different types of smart polymer-based delivery systems, such as sensitive to temperature, phase, pH, electric charge, light, and biochemicals, and their application in controlling the release of the incorporated drug to obtain a sustained plasma level has been discussed. Smart polymers, however, face challenges with regard to high burst release, unpredictable behavior in later part of biphasic release profile, overall drug release kinetics, conformational stability during processing, and preserving biological activity after getting released. Several patents overcoming these inherent problems associated with smart polymers have been reviewed. At the end, the future direction and potential of smart polymer-based delivery system for drug delivery has been presented in brief.

Herbal remedies for the treatment of periodontal disease--a patent review.

Abstract: Periodontal diseases, if left unchecked, can lead to major health problems. There are a number of traditional herbal remedies for the treatment and management of diseases related to teeth, gum and oral hygiene. Use of clove oil is an age old remedy still practiced for periodontal problems. Our aim is to present an overall view of the current strategies adopted for the formulation and application of traditional herbal remedies. The article provides a review of the patents obtained on herbal remedies for the treatment of periodontal diseases. In addition, it also provides an overall view of potent herbal remedies widely used for periodontal diseases.

Recent advances in oral pulsatile drug delivery.

Abstract: Pulsatile drug delivery aims to release drugs on a programmed pattern i.e.: at appropriate time and/or at appropriate site of action. Currently, it is gaining increasing attention as it offers a more sophisticated approach to the traditional sustained drug delivery i.e: a constant amount of drug released per unit time or constant blood levels. Technically, pulsatile drug delivery systems administered via the oral route could be divided into two distinct types, the time controlled delivery systems and the site-specific delivery systems. The simplest pulsatile formulation is a two layer press coated tablet consisted of polymers with different dissolution rates. Homogenicity of the coated barrier is mandatory in order to assure the predictability of the lag time. The disadvantage of such formulation is that the rupture time cannot be always adequately manipulated as it is strongly correlated with the physicochemical properties of the polymer. Gastric retentive systems, systems where the drug is released following a programmed lag phase, chronopharmaceutical drug delivery systems matching human circadian rhythms, multiunit or multilayer systems with various combinations of immediate and sustained-release preparation, are all classified under pulsatile drug delivery systems. On the other hand, site-controlled release is usually controlled by factors such as the pH of the target site, the enzymes present in the intestinal tract and the transit time/pressure of various parts of the intestine. In this review, recent patents on pulsatile drug delivery of oral dosage forms are summarized and discussed.

Recent patents review in microencapsulation of pharmaceuticals using the emulsion solvent removal methods.

Abstract: Several methods and techniques are potentially useful for the preparation of polymeric microparticles in the broad field of microencapsulation. The preparation method determines the type and the size of microparticle and influence the ability of the interaction among the components used in microparticle formulations. This review is devoted to describe and allocate the recently awarded and pending patents regarding the technical and formulation innovations in microparticles involved in drug delivery that are based mainly on the emulsion solvent removal methods. The term microparticle designates systems larger than one micrometer in diameter and is used usually to describe both microcapsules and microspheres. Microparticle-containing drugs are employed for various purposes including--but not restricted to--controlled drug delivery, masking the taste and odor of drugs, protection of the drugs from degradation, and protection of the body from the toxic effects of the drugs. Polymeric carriers being essentially multidisciplinary are commonly utilized in microparticle fabrication and they can be of an erodible or a non-erodible type.

Site specific chronotherapeutic drug delivery systems: a patent review.

Abstract: Oral dosage forms are known to provide a zero order or first order release in which the drug is released at a substantially steady rate of release per unit of time. However, there are instances where maintaining a constant blood level of a drug is not desirable. In such cases a pulsatile drug delivery may be more advantageous. Pulsatile drug delivery systems can be classified into site-specific systems in which the drug is released at the desired site within the intestinal tract (e.g., the colon), or time-controlled devices in which the drug is released after a well-defined time period. Environmental factors like pH or enzymes present in the intestinal tract control the release of a site-controlled system whereas the drug release from time-controlled systems is controlled primarily by the delivery system and not by the environment. The delayed liberation of orally administered drugs has been achieved through a range of formulation approaches, including single or multiple unit systems provided with release-controlling coatings, capsular devices and osmotic pumps. Our aim in this review is to outline the rational and prominent design strategies behind site-specific oral pulsatile delivery. The present article provides a good patent review regarding the Site Specific Chronotherapeutic Drug Delivery Systems.

Oral protein delivery: a patent review of academic and industrial approaches.

Abstract: Protein therapeutics are used in the treatment of a broad variety of diseases, however, usually they are not available as peroral formulations. Oral delivery systems of proteins including insulin, glucagon like peptide, calcitonin or parathyroid hormone are highly demanded by patients suffering from chronic diseases such as diabetes or osteoporosis. The need for oral protein formulations has been recognized by researchers of various scientific disciplines and a number of patents have been filed that deal with technologies capable of facilitating oral protein delivery. Within the current review, patents based on approaches such as particulate delivery systems, multifunctional polymers, enzyme inhibitors, permeation enhancers and ligand-specific binding and uptake are discussed. In addition, the technology platforms of several innovative drug delivery companies are highlighted.

Current ocular drug delivery challenges for N-acetylcarnosine: novel patented routes and modes of delivery, design for enhancement of therapeutic activity and drug delivery relationships.

Abstract: This review article explores the functional activity and development aspects of N-acetylcarnosine for the visual system as revealed by the use of a variety of biophysical, physiological and therapeutic ophthalmic methods. It is designed for pharmacists and more advanced ophthalmology, optometry and pharmacology researchers who wish to gain a basic understanding of the biological effects of N-acetylcarnosine for vision and to share in the excitement of the latest developments in this field. Topics under the consideration include: ophthalmic drug delivery of N-acetylcarnosine eye drops and challenging endeavors facing the pharmaceutical scientist; clinical and functional types of activity of the developed and patented N-acetylcarnosine lubricant eye drops designed as 1% N-acetylcarnosine prodrug of L-carnosine containing a mucoadhesive cellulose-based compound combined with corneal absorption promoters in a drug delivery system; management of age-related serious or disabling eye diseases in humans with N-acetylcarnosine eye drop therapeutic platform (age-related cataracts, ocular inflammation, age-related macular degeneration , macular dystrophies, ocular manifestations of diabetes , hypertonic retinopathy, primary open angle glaucoma, vitreous lesions) ; development and molecular mechanisms of ocular therapeutic activities of carnosine derivatives in the visual system. Through this article we can perceive some helpful recent patents according to the title of the issue. The biologically significant applications of carnosine mimetics including those in ophthalmology were patented by Dr. Babizhayev and the alliance Groups (WO 2004/028536 A1; WO 94/19325; WO 95/12581; WO 2004/064866 A1).

Drug Delivery Systems for Photodynamic Therapy

Abstract: Photodynamic therapy (PDT) is a medical treatment in which a combination of a photosensitizing drug and visible light causes destruction of selected cells. Over the past two decades, photodynamic therapy has enjoyed a period of intense investigation, both in the laboratory and in the clinic. Although still widely considered to be an experimental technique, its status and value within modern clinical practice continues to grow. The PDT field has, to date, been dominated by a small number of pharmaceutical companies and inhabited almost exclusively by clinicians and those involved in fundamental scientific research. True pharmaceutical formulation development has been limited, to some extent, by financial constraints. If PDT is to realise its undoubted potential in clinical practice it is important that awareness of the need for appropriate photosensitizer delivery systems is raised. Accordingly, this article deals with the innovations pertaining to drug delivery systems for photodynamic therapy as disclosed in recent patent literature.

A review of select recent patents on novel nanocarriers

Abstract: Nanocarriers offer several advantages in drug delivery including increased retention time in the body, the ability to solubilize hydrophobic cargo, and the ability to target specific tissues. These attributes have led to a large volume of research being dedicated to the development of novel nanocarriers and their use in treating disease. Many advances have been made in the synthesis and formulation of nanocarriers. For instance, flash precipitation and the use of rotary evaporator provide new methods for nanocarrier synthesis. Biomolecules like heparin and sarcosine have been successfully utilized for the synthesis of unique copolymers for use in nanocarrier systems. Also, the efficacy of nanocarrier targeting has been increased by taking advantage of unique microenvironments present in specific pathologies, utilization of phage properties, and scaffold systems for multiple targeting moieties. Finally, nanocarriers have been shown to provide immunomodulatory effects. This article provides a focused review of several recent patents covering the synthesis, composition and the use of novel nanocarriers.

Transdermal drug delivery system: patent reviews.

Abstract: Transdermal drug delivery represents one of the most rapidly advancing areas of novel drug delivery. Although the concept of transdermal drug delivery has been known since 1924, it took until 1979, as FDA approved the transdermal delivery of scopolamine, that transdermal delivery systems [TDDS] received broad attention as novel tool for controlled release. These drug delivery systems are designed for controlled release of drug through the skin into systemic circulation maintaining consistent efficacy and reducing dose of the drug and its related side effects. More than 200 patents have been granted by the United State patent alone, of which more than 35 TDD products have now been approved for sale in the US, and approximately 16 active ingredients have been approved for use globally. Statistics reveal a market of $ 12.7 billion in the year 2005 which is expected to increase by $ 21.5 billion in the year 2010 and $ 31.5 billion in the year 2015. Almost all major and minor pharmaceutical companies are developing TDDS. There is not a single review article which describes patents on different types of TDDS. Thus this review is designed for patents on the different type of TDDS which would be helpful for the researcher in the field of TDDS.

Impact of magnetic nanoparticles in biomedical applications.

Abstract: In the recent years, there has been a growing interest in the development of nanoparticles based targeting agents for the tumor diagnostics and therapeutics. This is because of their potential to detect the tumor and treat the diseased tissue at the cellular and molecular level. In this respect nanoscale magnetic materials have shown a very promising therapeutic concept and offer a new perspective for the diagnostic and target drug delivery approach. The magnetic nanocarriers have the ability to accumulate at any desired pharmacological site just by the guidance of external magnetic field. But, the interactions of these magnetic nanocarriers with the biological environment are rare and depend largely upon their surface chemistry and size. To increase the interactions and achieve the desired pharmaceutically acceptable delivery system, the surface of magnetic nanocarriers is modified in various ways by coating with organic polymers and inorganic metals or oxides. On the basis of surface characteristics, a number of effective magnetically driven therapies have been proposed by many researchers and protected through patents time to time.

Nanoparticles for gene delivery: a brief patent review.

Abstract: Gene therapy, as therapeutic treatment to genetic or acquired diseases, is attracting much interest in the research community, leading to noteworthy developments over the past two decades. Nonviral vectors have recently received an increasing attention in order to overcome the safety problems of viral counterpart. Nanoparticles with their special characteristics such as small particle size, large surface area and the capability of changing their surface properties have numerous advantages compared with other gene delivery systems. This article reviews the advances of nanoparticles in patents for gene delivery and emphasizes methods to promote gene transfection efficiency.