Intranasal Administration of a Polymeric Biodegradable Film to C57BL/6 Mice.

Nasal drug delivery in rodents is a challenging procedure, especially for brain targeting, as the position of the material in the nasal cavity determines the success of the administration method. The objective of this study was to assess a novel intranasal administration technique for nose-to-brain delivery of biodegradable nasal films. The method was performed in C57BL/6 (n = 10; age, 8 wk) under inhaled sevoflurane. Twenty-four gauge catheters were used for the procedure. Hydroxypropyl methyl-cellulosebased film was formed in the lumen of the catheter and then delivered into the mouse nostril by pushing it out of the lumen using a trimmed and polished needle. Methylene blue was incorporated in the film-forming gel to indicate the delivery area in which the films were deposited. After administration, all mice recovered from anesthesia without incident. None of the mice showed any signs of injury, discomfort, or nose bleeding, thus allowing us to characterize the administration method as noninvasive. Furthermore, postmortem evaluation revealed olfactory-centered placement of the polymeric films, confirming the accuracy and repeatability of the method. In conclusion, this study documented the use of, a novel, noninvasive, intranasal administration technique for nose-to-brain drug delivery in biodegradable films for use in mice.

Robust and sensitive high-performance liquid chromatographic-UV detection technique for the determination of tigecycline in rabbit plasma.

An isocratic HPLC method with detection at 248 nm was developed and fully validated for the determination of tigecycline in rabbit plasma. Minocycline was used as an internal standard. A Hypersil BDS RP-C18 column (250 x 4.6 mm, 5 microm particle size) was used with the mobile phase phosphate buffer (pH 7.10, 0.070 M)-acetonitrile (76 + 24, v/v) at a flow rate of 1.0 mL/min. The elution time of tigecycline and minocycline was approximately 8.1 and 9.9 min, respectively. Calibration curves of tigecycline were linear in the concentration range of 0.021-3.15 microg/mL in plasma. The LOD and LOQ in plasma were estimated as 7 and 21 ng/mL, respectively. The intraday and interday precision values of the method were in the range of 5.0-7.1 and 5.6-9.1%, while the corresponding accuracy values were in the ranges of 92.8-111.1 and 97.6-102.3%, respectively. At the LOQ, the intraday precision was 18.7%, while intraday and interday accuracy values were 97.3 and 98.0%, respectively. Robustness of the proposed method was studied using a Plackett-Burman experimental design. A pharmacokinetic profile is presented for confirmation of the applicability of the method to pharmacokinetic studies.