Cutaneous Permeation of a Percutaneously Applied Glucocorticoid Using Plant-Based Anionic Phospholipids in Hydrogenated Vegetable Oil: A Preliminary Study.

Purpose: It is important that, when corticosteroids are used therapeutically, concentrations be reduced as much as possible to mitigate potential adverse events and side effects. This preliminary study compares the permeation for the delivery of a corticosteroid in a 1% hydrocortisone-supplemented topical cream containing anionic polar phospholipids (APP) in hydrogenated vegetable oil (triglyceride) versus a market-leading 1% hydrocortisone in a mineral hydrocarbon-based skin cream. Methods: Using the Franz diffusion cell method with cadaveric skin, the permeation of a 1% hydrocortisone-supplemented cream containing APP (test preparation) was compared with a commercially available 1% hydrocortisone cream (control preparation). The principal APP in the test preparation were phosphatidylinositol, phosphatidylserine and phosphatidylglycerol. Permeation was determined at 4 and 8 h time intervals. Results: The permeation values for the 1% hydrocortisone supplemental APP cream (test preparation) were comparatively very high 1180 ng/cm2 at 4 h and 2173 ng/cm2 at 8 h, in contrast to the 1% hydrocortisone cream (control preparation) values of 13 ng/cm2 at 4 h and 98 ng/cm2 at 8 h. Permeation of skin cream increased significantly from 0 to 4 and 8 h, when comparing the APP test preparation with the control preparation (p < 0.001). This translates, respectively, into the 90-fold greater and a 20-fold greater penetration of the test preparation APP cream over the 1% hydrocortisone cream at 4 h and 8 h time points. Conclusions: This preliminary study demonstrates the enhanced permeation of 1% hydrocortisone when applied topically to the skin in an APP skin cream vehicle. This enhanced permeation suggests the potential use of APP technology to deliver therapeutically effective hydrocortisone treatment to the skin at markedly reduced concentrations of steroid. As such, APP technology may offer an improved approach to the treatment of dermatoses associated with inflammatory diseases and conditions requiring prolonged topical corticosteroid therapy.

Development and validation of a high-performance liquid chromatographic method for the analysis of budesonide.

A simple, rapid, and stability indicating reversed-phase high-performance liquid chromatography (HPLC) method of analysis for budesonide, a novel glucocorticoid prescribed for inflammatory bowel disease, was successfully developed. Budesonide is an epimeric mixture and both the epimers have similar anti-inflammatory activity. All the analytical methods reported in the literature are long and are based on separation of the epimers, thus our objective was to obtain a single sharp peak of the drug and to separate the drug peak from all the other degradation products. The method, was used to quantify budesonide in the developed formulation, employed a Kromasil C8, (150 mm x 4.6 mm) column with an isocratic mobile phase of acetonitrile-phosphate buffer (pH 3.2-0.025 M) (55:45 v/v), at a flow rate of 1.1 mL/min. Budesonide was detected by an ultraviolet detector at 244 nm. The method was validated for linearity, precision, repeatability, sensitivity, and selectivity. Selectivity was validated by subjecting stock solution of budesonide to acidic, basic, oxidative, and thermal degradation. The retention time of budesonide was about 4 min with symmetrical peaks. The method was linear over a concentration range 1-50 microg/mL (R2=0.9995). The limit of detection of budesonide was 0.1 microg/mL and the limit of quantitation was 0.25 microg/mL. The peaks of the degradation products did not interfere with the peak of budesonide. The developed method was used to quantify budesonide in budesonide-loaded micro-particles. Excipients present in the micro-particles did not interfere with the analysis and the recovery of budesonide from micro-particles was quantitative.

Quantitative in vitro comparison of fluorescein delivery to the eye via impregnated paper strip and volumetric techniques.

PURPOSE: To compare the quantity of fluorescein delivered to the eye via fluorescein-impregnated paper strips of various sizes and surface areas and via various microliter volumes of fluorescein sodium using an in vitro assay. METHODS: A commercially available fluorescein-impregnated strip (75 mm2) and three modified strips of reduced fluorescein-impregnated surface areas (10, 7.5, and 5.0 mm2) were used. The amount of fluorescein delivered to the eye for each of the four strips was approximated by applying each strip to a Whatman No. 1 filter paper under conditions simulating application of the strip to the eye, extracting the fluorescein from the filter paper in an aqueous solution, and performing spectrophotometric analysis at 484 nm. Similarly, this filter paper analytical system was calibrated using 1, 2, and 3 microl volumes of 2% w/v fluorescein delivered to the filter paper. RESULTS: Using calibration curves, linearity was observed between absorbance and concentration of fluorescein sodium with an R2 value > or = 0.99. Using these calibration curves, the amount of fluorescein delivered to the eye for the four strips and the three fluorescein solution samples was determined. Fluorescein-impregnated strips with surface areas of 75, 10, and 5 mm2 delivered approximately the same quantity of fluorescein to the ocular surface as 3 microl, 1 microl, and 0.5 microl of fluorescein 2% solution, respectively. CONCLUSIONS: The surface area of the fluorescein-impregnated portion of the strip can be designed to control the amount of fluorescein delivered to the eye.

A new high-performance liquid chromatography (HPLC) method for the analysis of halofantrine (HF) in pharmaceuticals.

A simple, rapid and stability-indicating reverse-phase high-performance liquid chromatography (HPLC) method was developed for the assay of halofantrine (HF) base, 1,3-dichloro-alpha-[2-(dibutylamino)ethyl]-6-(trifluoromethyl)-9-phenanthrenemethanol. The HPLC method was validated for precision, accuracy, selectivity and linearity and range. It was used to assay for HF base in solid dispersions. Excellent linearity was observed between HF base concentration and the peak area (R(2)=0.9998). The limit of detection was 1 ng (with a signal-to-noise ratio of 2:1), and the limit of quantitation was 10 ng (with a signal-to-noise ratio of 10:1). The method proved to be selective. Selectivity was validated by subjecting a stock solution of HF to acidic, basic, oxidative and thermal degradations. The peaks of the degradation products did not interfere with the peak of HF. Excipients present in the solid dispersions did not interfere with the analysis.

Preparation and in vitro evaluation of solid dispersions of halofantrine.

The low aqueous solubility of halofantrine (HF) and its low bioavailability from commercially available tablets (Halfan) suggested the formulation of solid dispersions (SDs) of HF to reduce its particle size and improve its wettability and aqueous solubility. Preformulation studies involved the development of a high performance liquid chromatography (HPLC) method for the analysis of HF. In addition, solubility studies were conducted on HF in aqueous solutions containing different concentrations of various carriers. Formulation studies included the preparation of SDs and physical mixtures (PMs) of HF with different carriers and their physicochemical characterization using differential scanning calorimetry (DSC), Fourier-Transform infra-red (FT-IR) spectroscopy and dissolution studies. A 3-month stability study at elevated temperatures was conducted on representative SDs of HF with selected carriers.