Recent Patents on Drug Delivery & Formulation - Volume 12, Issue 2, 2018

Background: Drugs having absorption window in the stomach or upper small intestine have restricted bioavailability with conventional dosage forms. The gastric residence time of these dosage forms is usually short and they do not show drug release for prolonged period of time. Objective: To avoid these problems and to enhance the bioavailability and gastric retention time of these drugs, controlled drug delivery systems with prolonged gastric retention time are currently being developed. Methods: This review highlights the various pharmaceutical approaches for gastroretention such as floating drug delivery systems, mucoadhesive systems, high-density systems, expandable and swelling systems, super porous hydrogels systems, magnetic systems, ion exchange resin system and recent patents filed or granted for these approaches. Results: Recently, some patents are also reported where a combination of various approaches is being employed to achieve very effective gastroretention. The various patent search sites were used to collect and analyze the information on gastroretentive drug delivery systems. Conclusion: The present study provides valuable information, advantages, limitations and future outlook of various gastroretentive drug delivery systems.

Background: Cervical cancer being the cancer of cervix is caused by an aberrant cell growth that acquires an ability to spread/ invade to other body parts. It has also been reported to be the second most common cause of death and cancer among women. Based on the severity of the disease, treatment aspects need to be explored more in order to overcome the limitations acquired by the conventional treatment. Recently, nanocarriers based drug delivery systems including liposomes, nanofibres, metallic NPs, polymeric NPs, dendrimers, polymeric micelles, antibody-drug conjugates, etc. have been explored to target and treat cervical cancer. Objective: This review highlights numerous recent research and patent reports as well on nanocarriers based systems. Methods: Patents viz US, EP and WIPO have been retrieved using sites www.uspto.gov/patft and www.freepatentsonline.com to collect literature on nanocarriers. Results: Various research reports and patents revealed nanocarriers to be effective in treating cervical cancer and these carriers are observed to be safer than the conventional treatment. Conclusion: Nanocarriers result in transforming drug distribution that can overpower drug resistance. Further, nanocarriers based drug delivery systems can particularly target drugs to cellular, subcellular and tissue sites. By enhancing the drug's bioavailability at the desired site, these systems result in therapeutic benefits like enhanced safety and efficacy. Also, in combination with other treatment approaches like radiation, photothermal and gene therapy, nanocarriers are reported to be quite effective and can define novel strategies to combat cervical cancer.

Background: Nowadays, Oral Film Technology (OFT) has gained much attention among all the oral drug delivery systems. Fast dissolving film, fast disintegrating film, and orodispersible film are some synonymous words for this dosage form. Without a need of liquid for administration, this dosage form dissolves in the mouth. Typically, fast dissolving film dissolves from 1 to 30 seconds. Objective: At the root of its originality, many researchers patented their work on the aspect of orodispersible films using different drugs, polymers, excipients and employing various methods of preparation. The review focuses on details related to orodispersible films and their patents from 1979-2017, collected from various sources like USPTO, Google patent, Espacenet, Intellectual Property India. Results: For the ease of discussion, collected patents are segregated on the basis of drugs, polymers, and method of preparation. It was found that many researchers are shifting towards fast dissolving films for better patient compliance, extended efficacy, high bioavailability, fast dissolution, and disintegration. With the help of polymers blend suitable for the drug release and improved method of preparation various parameters like tensile strength, thickness, and pH etc. can be controlled. Conclusion: It was observed that judicial selection of polymers and polymers blends and methods of preparation are key parameters in the formulation of orodispersible film.

Objective: The current work was attempted to formulate and evaluate the topical sustained release delivery systems called cubosomes containing Tretinoin for the acne treatment. The recent patents on various formulations of tretinoin (EP0408370A2) helped in selecting a new formulation and evaluation. Methods: Tretinoin loaded cubosomes were prepared by bottom-up technique, using varying the concentration of lipid and surfactant and keeping the drug concentration constant, a total of nine formulations of tretinoin was developed. These preparations were evaluated for surface charge, particle size, particle morphology, encapsulation efficiency, in-vivo and in-vitro release studies of gel enriched with cubosome dispersion. Finally, the stability studies of cubosomal gel were performed on optimized formulations. Results: Significant result were obtained with tretinoin formulation as the drug is lipophilic, so it gives more depot effect on the epidermis and good retention property. The data obtained from the formulations showed that formulation TCF-5 was the optimized formulation which exhibited better drug release and entrapment efficiency. Conclusion: It can be concluded that cubosomes offer benefits of quick onset as well as the maximal release of drug with fewer side effects. Thus, cubosomes represent a capable transporter having the property to sustain the release of drug, potential to localize the drug in the skin with a possible clinical application for acne vulgaris treatment due to cubosome depot effect on the epidermis.

Background: Nabumetone is biopharmaceutics classification system (BCS) class II drug, widely used in the treatment of osteoarthritis and rheumatoid arthritis. The most frequently reported adverse reactions for the drug involve disturbance in gastrointestinal tract, diarrhea, dyspepsia and abdominal pain. Microemulgel has advantages of microemulsion for improving solubility for hydrophobic drug. Patent literature had shown that the work for drug has been carried on spray chilling, enteric coated tablet, and topical formulation which gave an idea for present research work for the development of transdermal delivery. Objective: The objective of the present research work was to optimize transdermal microemulgel delivery for Nabumetone for the treatment of arthritis. Methods: Oil, surfactant and co-surfactant were selected based on solubility study of the drug. Gelling agents used were Carbopol 934 and HPMC K100M. Optimization was carried out using 32 factorial design. Characterization and evaluation were carried out for microemulsion and microemulsion based gel. Results: Field emission-scanning electron microscopy (FE-SEM) study of the microemulsion revealed globules of 50-200 nm size. Zeta potential -9.50 mV indicated good stability of microemulsion. Globule size measured by dynamic light scattering (zetasizer) was 160nm. Design expert gave optimized batch as F7 which contain 0.2% w/w drug, 4.3% w/w liquid paraffin, 0.71% w/w tween 80, 0.35% w/w propylene glycol, 0.124% w/w Carbopol 934, 0.187% w/w HPMC K100M and 11.68% w/w water. In-vitro diffusion study for F7 batch showed 99.16±2.10 % drug release through egg membrane and 99.15±2.73% drug release in ex-vivo study. Conclusion: Nabumetone microemulgel exhibiting good in-vitro and ex-vivo controlled drug release was optimized.