Validation study of the unguator, an apparatus for compounding dermatological preparations.

A study was conducted at the Laboratory of Pharmaceutical Technology, University of Liege, Belgium, of the performance of the Unguator Mixing System, an instrument belonging to a new generation of electronic mortar and pestle apparatus, which was designed to improve pharmaceutical compounding, provide pharmaceutically elegant preparations, and reduce nonproductive time. The goal of this study was to verify that preparations that met the actual quality criteria established by the United States Pharmacopeia, the Therapeutic Compounding Formulary, and the British Pharmacopoeia could be achieved by using the Unguator Mixing System. To achieve this goal, the optimal conditions, such as speed, mixing time, and order of addition of the components, were determined for each of several representative preparations.

Nasal mucoadhesive drug delivery: background, applications, trends and future perspectives.

Nasal drug delivery has now been recognized as a very promising route for delivery of therapeutic compounds including biopharmaceuticals. It has been demonstrated that low absorption of drugs can be countered by using absorption enhancers or increasing the drug residence time in the nasal cavity, and that some mucoadhesive polymers can serve both functions. This article reviews the background of nasal mucoadhesive drug delivery with special references to the biological and pharmaceutical considerations for nasal mucoadhesive drug administration.

Mucosal response in African catfish after administration of Vibrio anguillarum O2 antigens via different routes.

The aim of this study was to investigate the possibility of mucosal vaccination in African catfish (Clarias gariepinus) with Vibrio anguillarum O2 bacterins. The antigen was administered via different routes: anal intubation, oral administration, intraperitoneal injection and immersion. To monitor the antigen uptake, a competitive ELISA was used.

Intravaginal gels as drug delivery systems.

Recently, there has been a great deal of interest in the design and application of different dosage forms via the vaginal route. Several studies have proven that the vagina is an effective route for drug administration intended mainly for local action, but systemic effects of some drugs also can be attained. The major advantages of this route include accessibility, good blood supply, the ability to bypass first-pass liver metabolism, and permeability to large molecular weight drugs, such as peptides and proteins.

Metabolism and absorption enhancement of methionine enkephalin in human nasal epithelium.

The objective of this study was to investigate absorption enhancing approaches for systemic delivery of methionine enkephalin via the nose. Absorption promotion of methionine enkephalin in the presence of protease inhibitors (bestatin, puromycin) and absorption enhancers (glycocholate, dimethyl-beta-cyclodextrin) were investigated in human nasal epithelium. Co-administration of the peptide with protease inhibitors and absorption enhancers resulted in a remarkable increase in Met-Enk permeation (4- to 94-fold).

Oral vaccination of African catfish with Vibrio anguillarum O2: effect on antigen uptake and immune response by absorption enhancers in lag time coated pellets.

The impact on antigen uptake and antibody response by the addition of absorption enhancers to Vibrio anguillarum O2 antigen was studied in oral vaccination trials of African catfish (Clarias gariepinus). Oral vaccination was achieved by feeding lag time coated pellets. The lag time coat prevents premature release of the encapsulated vaccine in the tank, before ingestion of the pellets by the fish.

In vitro polarized transport of L-phenylalanine in human nasal epithelium and partial characterization of the amino acid transporters involved.

Purpose: The purpose of this study was to provide functional and molecular evidence to support the existence of large neutral amino acid transporters in human nasal epithelium using nasal primary cell culture model.

Methods: L-Phenylalanine was used as a model substrate to characterize carrier-mediated permeation of amino acids across human nasal epithelium. The influence of temperature, concentration, other amino acids, metabolic/transport inhibitors, and polarity/stereo-selectivity on transport of the model compound was investigated.

Mechanistic appraisal of the effects of some protease inhibitors on ciliary beat frequency in a sequential cell culture system of human nasal epithelium.

The aim of this study was to investigate the suitability of a sequential monolayer-suspension culture system as a model to screen subacute effects of drug excipients on ciliary beat frequency (CBF). The CBF of the cultured cells was measured by computerized microscope photometry. Protease inhibitors (puromycin, bestatin, bacitracin, actinonin and thiomersal) were used as model compounds and the mechanisms of ciliary inhibition were investigated by probing the involvement of arachidonic acid metabolism, guanylate cyclase (cGMP), protein kinase C (PKC) and adenosinetriphosphate (ATP) inhibition.

Characterization of methacrylated inulin hydrogels designed for colon targeting: in vitro release of BSA.

Purpose: To characterize methacrylated inulin hydrogels with respect to their release properties.

Methods: Proteins (bovine serum albumin or lysozyme) were used as model drugs and were loaded during or after hydrogel formation. Parameters such as the drug loading method, the molecular weight of the proteins, the initial drug loading concentration, the hydrogel feed composition, degree of substitution, and size of the hydrogel were investigated by determining the release of the model proteins from the hydrogels in a phosphate buffer solution.

Development of a lag time coating for drug-layered fish feed pellets.

The purpose of this work was to develop a release-delaying coat for drug-layered fish pellets, in order to prevent a premature release of the drug in the tank water but allowing a rapid release after uptake by the fish. Blank pellets were prepared in a rotary processor and drug layered in a Wurster coater with bovine serum albumin or riboflavin using hydroxypropyl methyl cellulose (HPMC) as a binder. On the drug-loaded pellets, different mixtures of ethyl cellulose (EC) and HPMC were applied as the release-delaying coat.

Characterization of human nasal primary culture systems to investigate peptide metabolism.

The objectives of this study were to validate and compare the suitability of different primary cell culture systems as models to investigate peptide enzymatic stability following nasal administration. The degradation kinetics of a model peptide, leucine enkephalin (Tyr-Gly-Gly-Phe-Leu, Leu-Enk), was determined in four nasal cell culture systems: immersion, air-liquid interface, sequential monolayer-suspension, floating collagen. The influence of enzyme inhibitors (bestatin, puromycin) and Leu-Enk metabolite analogs (Tyr-Gly, Phe-Leu, Tyr-Gly-Gly, Gly-Phe-Leu) on the Leu-Enk degradation profile was also investigated.

Nasal absorption enhancement strategies for therapeutic peptides: an in vitro study using cultured human nasal epithelium.

This study examined the potential usefulness of cultured human nasal epithelium as a model to investigate nasal absorption enhancement strategies for therapeutic peptides. The transport of leucine enkephalin (Leu-Enk) in the presence of bestatin and puromycin, respectively and various combinations of these protease inhibitors with absorption enhancers capable of inhibiting proteases or protecting peptides against protease degradation (glycocholate, dimethyl-beta-cyclodextrin (DM beta CD)) was studied. Epithelial membrane perturbation, protein leakage, bestatin/puromycin absorption and rebound aminopeptidase activity were used as toxicological end-points.

Polysaccharides as excipients for colon-specific coatings. Permeability and swelling properties of casted films.

Oligosaccharides such as inulin (In) and polysaccharides such as galactomannans, combined with polymethacrylates on isolated films for film coatings, were obtained from aqueous-based solvents and investigated as potential vehicles for colonic drug delivery. These compositions, which are susceptible to fermentation by colonic microflora, constitute promising excipients for the development of new colon-specific therapeutic systems. The characteristics of several compositions have been demonstrated in permeability and swelling studies on isolated films composed of a polymethacrylate associated with In or galactomannans of mesquite seed gum (MSG).