Special Issue "The Progress on Pharmaceutics in Drug Delayed Release System"

Guest Editor
Prof. Dr. Neal M. Davies
Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Wegner Hall, Pullman, WA 99164-6534, USA
Website: http://www.pharmacy.wsu.edu/PharmSci/davies.html
E-Mail: ndavies@wsu.edu
Phone: +1 509 335 4754
Fax: +1 509 335 5902
Interests: pharmacokinetics; chirality; formulation and drug delivery and physical characterization of drugs and dosage forms

Dear Colleagues,

It is often important to maintain therapeutic plasma concentrations for drugs exhibiting a short terminal half-life; for this, dosage forms with a lower input rate have been developed and pharmaceutical manufacturing of controlled, extended, and sustained release formulations have developed and evolved. With the advent of a variety of new delivery platforms and systems, formulations, biomaterials, technologies and a plethora of exciting selected therapeutic approaches significant progress on the pharmaceutics of drug delayed release systems has ensued. Therapeutic delivery of macromolecules is evolving with the aim of controlling absorption, distribution, metabolism, and cellular uptake through programmed drug delivery. Specifically, drug targeting by carriers utilizing pro-drugs, synthetic polymers, lipids, and various nanocarrier approaches is becoming more frequently incorporated into drug controlled release systems. This alteration and manipulation of input and output rates of drugs is becoming increasingly complex and drug delivery has evolved in advancing and altering release. This special issue serves to highlight and capture  a variety of advances and illustrate the remaining challenges of contemporary progress in the pharmaceutics of drug modified release systems. We invite articles on all aspects of pharmaceutics in drug delayed release systems for this special issue.

Prof. Dr. Neal M. Davies
Guest Editor

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Pharmaceutics is an international peer-reviewed Open Access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 300 CHF (Swiss Francs). English correction and/or formatting fees of 250 CHF (Swiss Francs) will be charged in certain cases for those articles accepted for publication that require extensive additional formatting and/or English corrections.

• drug delivery
• drug release
• drug formulation
• dosage forms
• Nanocarrier technologies
• Sustained release
• Lipids
• polymers
• delayed release
• modified release
• biomaterials

Type of Paper: Article
Title: Stabilization of Solid Lipid Nanoparticles Using Alkyl Polyglucoside Surfactant
Authors: Andjelka Kovacevic ¹, Snezana Savic ¹, Gordana Vuleta ¹, Rainer H. Müller ² and Cornelia M. Keck ²
Affiliations: ¹ Department of Pharmaceutical Technology and Cosmetology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, P.O. Box 146, 11221 Belgrade, Serbia
² Department of Pharmaceutics, Biopharmaceutics and NutriCosmetics, Freie Universität Berlin, Kelchstraße 31, 12169 Berlin, Germany;
E-Mail: ck@ckc-berlin.de (C.M.K.)
Abstract: Alkylpolyglucosides (APGs) arenonionic surfactants that are highly skin compatible and fully biodegradable.Moreover, they are produced from renewable sources only. Thus, these surfactants are interesting stabilizers for dermal application also in the pharmaceutical field. In this study two APGs, differing in alkyl chain lengths, were used to produce solid lipid nanoparticles (SLN). The physico-chemical parameters, e.g. particle sizeand size distribution, zeta potential, crystallinity and physical stability of SLN, as well as contact angle of surfactant solution on the melted lipid film were assessed to evaluate the suitability of these surfactants for the stabilization of SLN. The contact angles increased with increasing alkyl chain lengths which resulted in an increasing particle size of SLN. With increasing numbers of homogenization cycles this difference in size was decreased, leading to almost identical particles with a mean sizes of 168.9±3.2 nmand a very narrow size distribution (polydispersity index < 0.1) for both SLN after 5 cycles at 500 bar. Data showed a high physical stability for both formulations at various storage temperatures (5°C±3°C, 25°C±2°C and 40°C±2°C) during 180 days of investigation. Good physical stability of APG-SLN was confirmed also by zeta potential analysis. The stabilization effect of APGswas explained as a superposition of electro-static and steric stabilization. The crystallinity of SLN was decreased when compared to the bulk lipid. The major reason is the small particle size and in addition an interaction with the stabilizers. It was found that a shorter alkyl chain length led to a more pronounced decrease in crystallinity. This is in agreement with previous studies.In conclusion: APGs investigated were found to be highly efficient stabilizers for SLN.
Keywords: solid lipid nanoparticles; alkyl polyglucoside surfactant; dermal application

Type of Paper: Review
Title: Drug Delivery Systems in Melanoma-An Update
Authors: Hareesh B. Nair, Shylesh S. Bhaskaran, John L. VandeBerg
Affiliation: Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX 78227, USA
Abstract: Melanoma is the most common and serious form of skin cancer among cutaneous cancers. Despite of advanced scientific as well as clinical developments the rate of cutaneous melanoma is increasing in skyrocketing pace. As per recent statistics of American Cancer Society, an estimated 11,790 deaths will occur due to skin cancers in 2010 and out of which melanoma contributes 8,700 deaths (ACS Cancer facts and figures, 2010). The propensity of metastatic spread at an early stage is the major attributing factor of melanoma disease progression and hence prerequisite to developing melanoma chemoprevention should focus primarily on sustained angiogenesis and tissue invasion. In order to improve the therapy there is an unmet need to reengineer the existing drugs to increase the efficacy and to enhance the sustained and precise delivery of these drugs. In this decade, there is enough evidence to believe that nanotechnology would bring hope for better treatment of melanoma. Nanotechnology could help to improve the existing drugs through many different drug delivery platforms including transdermal, implanted, drug loaded targeted particles, drug conjugates, osmotic pressure driven delivery, stealth liposomes, polymer particle/ conjugates and siRNA particles delivery. The rational design for an effective delivery focuses on multiple factors include quantity of the drug based on dose-effect relationship, delivery rate, duration of delivery, site of action, bioavailability and metabolic byproducts of the vehicle agent. The side effects of melanoma chemotherapy depend mainly on the drugs and the doses received like any other chemotherapy.  Controlled release nanomedicine may increase patient compliance, safety, improved therapy and decrease cost by more efficient use of the drug at lower doses. In this review, we are addressing challenges in current melanoma therapy, experimental models in melanoma research, drug delivery systems and drug formulations in melanoma treatment.
Key words: Drug delivery, nanoparticles, liposome, melanoma, nanotechnology