Recent Patents on Drug Delivery & Formulation (v.6, #3)

Acknowledgement to Reviewers by Bentham Science Publishers (i-i).
Bentham Science Publishers would like to thank and appreciate the co-operation from all reviewers for their constructive comments and feedback on the manuscripts submitted to “Recent Patents on Drug Delivery & Formulation”. Their efforts have contributed greatly to the high quality and continuous growth of the journal. Given below is the list of reviewers who reviewed articles for the Journal in the year 2012:....

Impact of the Emulsification-Diffusion Method on the Development of Pharmaceutical Nanoparticles by David Quintanar-Guerrero, Maria de la Luz Zambrano-Zaragoza, Elsa Gutierrez-Cortez, Nestor Mendoza-Munoz (184-194).
Nanotechnology is having a profound impact in many scientific fields and it has become one of the most important and exciting discipline. Like all technological advances, nanotechnology has its own scientific basis with a broad interdisciplinary effect. Perhaps, we are witnessing an exponential growth of nanotechnology, reflection of this is the important increase in the number of patents, scientific papers and specialized “nano” meetings and journals. The impact in the pharmaceutical area is related to the use of colloidal drug delivery systems as carriers for bioactive agents, in particular, the nanoparticle technology. The term nanoparticles designates solid submicronic particles formed of acceptable materials (e.g. polymers, lipids, etc.) containing an active substance. It includes both nanospheres (matricial systems) and nanocapsules (membrane systems). The knowledge of the nanoparticle preparation methods is a key issue for the formulator involved with drug-delivery research and development. In general, the methods based on preformed polymers, in particular biodegradable polymers, are preferred due to their easy implementation and lower potential toxicity. One of the most widely used methods to prepare polymeric nanoparticles is emulsification-diffusion. This method has been discussed in some reviews that compile research works but has a small number of patents. In this review, the emulsificationdiffusion method is discussed from a technological point of view in order to show the operating conditions and formulation variables from data extracted of recent patents and experimental works. The main idea is to provide the reader with a general guide for formulators to make decisions about the usefulness of this method to develop specific nanoparticulate systems. The first part of this review provides an overview of the emulsification-diffusion method to prepare polymeric nanoparticles, while the second part evaluates the influence of preparative variables on the properties of the obtained particles relating the events to the formation mechanism. Novel innovations and applications of the method have also been compiled.

Spray-Dried Polymeric Nanoparticles for Pharmaceutics: A Review of Patents by Ruy C.R. Beck, Aline F. Ourique, Silvia S. Guterres, Adriana R. Pohlmann (195-208).
Polymeric nanoparticles have been the focus of several researches in the last three decades in diverse areas including the delivery of pharmaceutical, diagnostic and cosmetic agents. These nanocarriers are able to improve the bioavailability and intrinsic solubility of drugs, to target different agents to a specific location or to protect the agent against extrinsic factors, such as radiation and extreme pH conditions. Despite the high interest in the development of these formulations, they hold some disadvantages like the limited physicochemical stability, which hinders the scaling-up of the preparation methods. In this context, spray-drying techniques have been proposed to obtain powder compositions containing polymeric nanoparticles allowing this limited property to be circumvented. In this context, this review is focused on the latest patents related to obtaining spray-dried polymeric nanoparticles, which have been divided into three different groups, according to their approach: i) spray-drying solutions to obtain nanoparticles, ii) spray-drying emulsions/ dispersions to obtain nanoparticles, and iii) nanoparticles dried by spray-drying.

Single Emulsion-Solvent Evaporation Technique and Modifications for the Preparation of Pharmaceutical Polymeric Nanoparticles by Maria G. Nava-Arzaluz, Elizabeth Pinon-Segundo, Adriana Ganem-Rondero, David Lechuga-Ballesteros (209-223).
In recent years, there has been an increased interest in using nanoparticles for drug delivery and pharmaceutical development. Nanoparticles can offer significant advantages over the conventional drug delivery systems in terms of high drug loading, stability and specificity, controlled release capability, and the ability to deliver both hydrophilic and hydrophobic drug molecules through various routes of administration. This review article focuses on the use of the single emulsion solvent evaporation method, the first method proposed for the preparation of polymeric nanoparticles, and modifications that have been developed over the years to improve the results obtained with this technique.

Pharmaceutical Polymeric Nanoparticles Prepared by the Double Emulsion- Solvent Evaporation Technique by Elizabeth Pinon-Segundo, Maria G. Nava-Arzaluz, David Lechuga-Ballesteros (224-235).
The most common technique to produce nanoparticles involves evaporation of a polymer emulsion to obtain polymeric particles less than 500 nm in size. And since its introduction in the late 1970's, this process has been widely used for pharmaceutical applications to obtain clinically applicable drug delivery systems. Many adjustments and adaptations of this technique have been made, attempting encapsulation of a wide variety of bioactive compounds. The advantages and drawbacks of the single-emulsion and especially double (multiple)-emulsion techniques are discussed in the present review article. It covers patent and patent applications literature, as well as peer reviewed research papers discussing pharmaceutical polymer-based nanoparticles obtained by the double emulsion-solvent evaporation technique using preformed polymers.

The recent advances in nanotechnology and its application in medicine have merged into a new concept called nanomedicine. Colloidal drug delivery systems and specifically polymeric nanoparticles are one of the most promising novel drug carriers due to their capacity for passive or active targeting for therapeutic and diagnostic applications. The introduction of novel therapeutic nanoscaled agents requires simple, efficient and feasible industrial-scale production methods. Biodegradable polymeric nanoparticles are usually prepared from preformed polymers by five techniques: emulsification- solvent evaporation, solvent displacement, salting-out, emulsification-solvent diffusion and double emulsionsolvent evaporation. This review discusses the use of the salting-out technique for the preparation of nanoparticles in the development of systems for drug delivery and other pharmaceutical applications. The relevant applications, formulations and release characteristics of novel colloidal drug delivery preparations from research literature and patents are summarized. This review is intended as a tool for the rational development of polymeric colloidal systems for pharmaceutical use.

Nanoparticles via Nanoprecipitation Process by Audrey Minost, Jean Delaveau, Marie-Alexandrine Bolzinger, Hatem Fessi, Abdelhamid Elaissari (250-258).
Various encapsulation approaches have been explored during the last years in order to encapsulate classical active molecules and new synthesized molecules principally for the in vivo therapy as drug delivery nanocarriers and also for the in vivo biomedical diagnostic. These approaches lead to new and versatile systems exhibiting high encapsulation yields of small molecules mainly. Due to the use of biodegradable polymers, the final particles and dispersions exhibit low cytotoxicity and in some cases total biocompatibility. To enhance local targeting efficiency, nanoparticles are chemically grafted using specific antibody for a specific disease. One of the easiest processes leading to rapid particles formation is the nanoprecipitation. Such process is mainly based on polymer transfer from good solvent to poor solvent condition, leading consequently to nanoparticles formation via self-assembly of precipitated polymer chains. The article discussed some of patents associated with Nanoprecipitation Process.

Modified Alginate Beads for Mucoadhesive Drug Delivery System: An Updated Review of Patents by Suryakanta Swain, Aurobinda Behera, Sarwar Beg, Chinam N. Patra, Subash C. Dinda, Jammula Sruti, Muddana E. B. Rao (259-277).
Pharmaceutical research and inventions are increasingly developed for the design of an ideal dosage regimen in drug therapy of many diseases, which attains therapeutic concentration of drug in plasma and maintains it constant for the entire duration of treatment and also minimizes the side effects. Recent trends in pharmaceutical technology indicated that mucoadhesive micro particle and modified alginate beads as drug delivery system especially suitable for achieving delivery of drug in a predetermined rate locally or systemically for a prolonged period of time. The release of drug from microparticle depends on a variety of factors including carrier used to form the micro particle and amount of drug contained in them. The main aim of the present review is to explain the various theories, mechanisms, advanced mucoadhesive polymers, various delivery approaches, methodologies for developing a mucoadhesive micro-particle and modified alginate beads formulation, in vitro, ex vivo and in vivo characterization. Apart from this, an innovative test method that is biacore is highlighted in this review to measure the mucoadhesive strength. This review is also briefly explained about the updated patenting system for the development of micro-particle and modified alginate beads as drug delivery system.

Recent Advances and Patent Perspectives in Gastroretentive Technology by Rakesh Pahwa, Manisha Singh, Vipin Kumar, Kanchan Kohli (278-290).
Gastroretentive drug delivery technology has emerged as an efficient approach for enhancing the bioavailability and controlled delivery of various therapeutic molecules. Myriad of patents issued in the vistas of gastroretentive technology have inspired scientific community worldwide to develop more innovative strategies for the fabrication of drug delivery devices which can be retained in stomach for a controlled period of time. The present paper describes various recent efforts and technological advancements of gastroretentive drug delivery systems along with potential advantages and available marketed preparations. Numerous significant patents concerning gastroretentive drug delivery devices are also highlighted.

Patent Selections: by Bentham Science Publishers (291-292).
The patents annotated in this section have been selected from various patent databases. These recent patents are relevant to the articles published in this journal issue, categorized by therapeutic areas/targets and therapeutic agents related to drug delivery and formulations.....