High performance liquid chromatography determination of dexamethasone in plasma to evaluate its systemic absorption following intra-space pterygomandibular injection of twin-mix (mixture of 2 % lignocaine with 1:200,000 epinephrine and 4 mg dexamethasone): randomized control trial.

PURPOSE: To determine systemic absorption of dexamethasone by detection of plasma concentration using high performance liquid chromatography following its administration along with local anesthetic agent as a mixture via pterygomandibular space. METHODS: A prospective randomized double-blind clinical study was undertaken to analyze the plasma concentration of dexamethasone after intra-space pterygomandibular injection along with local anesthesia. The study was performed as per split mouth model where the mandibular quadrant allocation was done on a random basis considering each of the 30 patients is included in the two study interventions (SS and CS). For the study site (SS) procedures, dexamethasone was administered as a mixture (2 % lignocaine with 1:200,000 epinephrine and 4 mg dexamethasone) intra-space. In the control site (CS) procedures, a regular standard inferior alveolar nerve block was administered, and dexamethasone was given as intramuscular injection. The plasma dexamethasone determination was done in venous blood 30- and 60-min post injection using high performance liquid chromatography (HPLC). The clinical parameters like pain; swelling; and mouth opening on the first, third, and seventh post-operative day were analyzed and compared. RESULTS: No significant difference was found in the clinical parameters assessed; comparative evaluation showed less swelling in the SS interventions. The plasma concentration of dexamethasone for the CS interventions was 226 ± 47 ng/ml at 30-min and 316 ± 81.6 ng/ml at 60-min post injection, and for SS, it was 221 ± 81.6 ng/ml at 30-min and 340 ± 105 ng/ml at 60-min post injection. On inter-site (CS and SS) comparison, no statistically significant difference was ascertained in dexamethasone plasma concentration at 30-min post injection (P = 0.77) and at 60-min post injection. (P = 0.32). CONCLUSION: Intra-space (pterygomandibular space) administration of dexamethasone can achieve statistically similar plasma concentration of the drug as when the same dose is administered intramuscularly with demonstration of similar clinical effects.

Design and development of solid lipid nanoparticles for topical delivery of an anti-fungal agent.

Topical application of the drugs at the pathological sites offers potential advantages of delivering the drug directly to the site of action. The main aim of this work was to formulate and evaluate Miconazole nitrate (MN) loaded solid lipid nanoparticles (SLN) for topical application. MN-loaded SLN were prepared by modified solvent injection method and characterized for shape, surface morphology, particle size, and drug entrapment. These solid lipid nanoparticles were spherical in shape with smooth surface and possessed mean average size of 206.39 +/- 9.37 nm. In vitro drug release of MN-loaded SLN-bearing hydrogel was compared with MN suspension and MN hydrogel; MN-loaded SLN-bearing hydrogel depicted a sustained drug release over a 24-h period. Tape stripping experiments demonstrated 10-fold greater retention with MN-loaded SLN-bearing hydrogel as compared to MN suspension and MN hydrogel. The in vivo studies were performed by infecting the rats with candida species. It was observed that MN-loaded SLN-bearing hydrogel was more efficient in the treatment of candidiasis. Results indicate that MN-loaded SLN-bearing hydrogel provides a sustaining MN topical effect as well as quicker relief from fungal infection.

Metronidazole loaded pectin microspheres for colon targeting.

A multiparticulate system having pH-sensitive property and specific enzyme biodegradability for colon-targeted delivery of metronidazole was developed. Pectin microspheres were prepared using emulsion-dehydration technique. These microspheres were coated with Eudragit(R) S-100 using oil-in-oil solvent evaporation method. The SEM was used to characterize the surface of these microspheres and a distinct coating over microspheres could be seen. The in vitro drug release studies exhibited no drug release at gastric pH, however continuous release of drug was observed from the formulation at colonic pH. Further, the release of drug from formulation was found to be higher in the presence of rat caecal contents, indicating the effect of colonic enzymes on the pectin microspheres. The in vivo studies were also performed by assessing the drug concentration in various parts of the GIT at different time intervals which exhibited the potentiality of formulation for colon targeting. Hence, it can be concluded that Eudragit coated pectin microspheres can be used for the colon specific delivery of drug.