Recent Patents on Drug Delivery & Formulation - Volume 5, Issue 2, 2011

Vaginal route serves as a potential site of drug administration for local and systemic absorption of a variety of therapeutic agents. Despite being a non- invasive route of drug administration, the vagina has not been extensively explored as compared to other routes. Intravaginal drug delivery has been traditionally restricted to delivery of antinfectives to the local vaginal cavity. Concerted efforts have been made in the recent past to rediscover the vaginal route as a potential route for the delivery of therapeutically important molecules, proteins, peptides, small interfering RNAs, oligonucleotides, antigens, vaccines and hormones. The understanding of vaginal physiology has led to the design of specific intravaginal drug delivery systems to reach the systemic circulation. To overcome the limitations of conventional dosage forms administered through vaginal route various novel approaches like the use of mucoadhesive or bioadhesive polymers, pH- or temperature-sensitive polymers, liposomes, nanoemulsions, nanoparticles, vaginal inserts, multiple emulsions and hydrogels have been designed which enable controlled and prolonged release of drugs. The present article is a comprehensive review of the research and patents encompassing conventional dosage forms used for vaginal drug delivery with emphasis on newer platform technologies pertaining to intravaginal administration.

Microneedle mediated microporation has proved its potential to enhance the delivery of therapeutic drug molecules through skin over the last one decade. Several patents have been granted and cutting edge research is going on particularly for the delivery of biopharmaceuticals (macromolecules like protein or peptides). The technology involves use of micron sized needles made of diverse materials to form microchannels into the stratum corneum (or deeper), outermost barrier layer of the skin. These microchannels are deep enough to facilitate efficient drug delivery through disrupted stratum corneum but short enough to avoid bleeding or pain. So far, the microneedle technology has been explored for drug and vaccine delivery through transcutaneous route. However, the miniaturized nature of these microneedles and anticipated minimal invasiveness has led the scientists to explore and patent its possible use for several other applications. The use of this technology in combination with other enhancement techniques has also gained recent attention. This review article focuses on the latest developments in the field of microneedles as described in patent and research literature. Comprehensive review of several topics including device design/fabrication, formulation development, safety/regulatory issues, therapeutic applications and major challenges in the commercialization of microneedles as medical devices has been presented here.

The parenteral route of administration is the most effective route for the delivery of the active pharmaceutical substances with narrow therapeutic index, poor bioavailability especially for those drugs, prescribed to unconscious patients. To maintain a therapeutic effective concentration of the drug, it requires frequent injections which ultimately lead to patient discomfort. In parenteral drug delivery, major progress has been done in the field of formulation technologies so as to provide a targeted and sustained release of drug in predictable manner. The present article reviews recent patents and major advancements in parenteral drug delivery systems along with general introduction. This article also deals with importance of novel systems in drug delivery to overcome the problems associated with conventional parenteral drug delivery systems.

The eye due to its special attributes is an effortlessly accessible location for topical drug administration. Topical administration not only provides local targeting of drugs but also offers a better control over the systemic delivery. Bioavailability of drugs from ocular dosage forms is dependent to the precorneal loss factors (physiological and anatomical constraints of eye) thus, very small fraction of the drug is absorbed through ocular route. The effective dose of medication administered ophthalmically may be altered by changing the formulation. Various research reports have been documented for ocular drug delivery, both on academic level as well as commercial level resulting in augmented increase in the numbers of patents in this field. The primary objective of the present review is to provide an overview of the ocular drug delivery systems with special emphasis on the intellectual aspects of these systems. This paper also attempts to extend the information on ocular drug delivery systems already existing in the literature by focusing on the update on the patents granted as well as applications published for these systems during the last decade.

Nanoemulsions have garnered considerable attention in research as well as in therapeutics due to their advantages like thermodynamic stability, optical clarity, ease of preparation, and unique property of behaving as supersolvent for solubilizing both hydrophobic and hydrophilic solutes. Due to above mentioned attributes, nanoemulsions find numerous applications in diagnosis as well as therapy of diseases. Hence, the aim of the current review is to recapitulate these applications of this novel drug delivery system by discussing the patents governing various applications of this system.

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.