Orodispersible Films: A Systematic Patent Review.
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.
Formulation of Mouth Dissolving Strips of Metoprolol Succinate Using Locust Bean Gum
The current project was carried out to investigate the use of locust bean gum as a film forming agent in the development of fast dissolving oral strips that can be utilized for the drug administration in urgent situations such as convulsive seizures, hypertension and dysphasia. Oral strips of locust bean gum were formulated using solvent casting method containing metoprolol succinate as model drug. (T1- T9) placebo films were formulated initially using different concentrations of locust bean gum to assess the film forming ability of the locust bean gum. Crospovidone and PEG-200 were used as disintegrating agent and plasticizer respectively. Stability against moisture was improved by addition of beeswax. Formulated films (T1-T9) were evaluated for their appearance, film forming capacity, moisture permeability, weight variation and thickness. Placebo film formulations T4 and T6 consisting of locust bean gum (0.6 gm), beeswax (0.1 gm) and crospovidone (4%), 0.3 and 0.9 ml of PEG-200 respectively were selected for drug loading. Drug loaded films (F1 and F2) were characterised for parameters such as weight variation, film thickness, folding endurance, drug content uniformity, in vitro disintegration time, in vitro drug release, tensile strength and surface pH. Composition F2 comprising of locust bean gum (0.6 gm) and 0.9 ml of PEG- 200 was chosen as optimized formulation. Stability studies of optimized drug loaded formulation was done as per ICH guidelines of stability. Locust bean gum appears as a good alternative over the various synthetic polymers utilized in the formulation and development of oral strips/ films.
Microstructure of the solder-casting zone in bridges of dental gold alloys.
The composition and structure were studied in the cast and in the solder of bridges which had failed clinically. Both materials were gold alloys but with different contents of Pt, Ag and Zn. The metallographic investigation revealed defects mostly in the solder, situated in the subsurface layer. SEM studied of the fracture surface revealed large porosites and a structure of dense parallel lines--striations--, indicating that the material had failed from fatigue. The materials in the fractured bridges were identified by micro-probe measurements. It was stated that cast material and solder material used together, were of different composition.