Gülgün Yener

Importance of using solid lipid microspheres as carriers for UV filters on the example octyl methoxy cinnamate.

The aim of this study was to prepare solid lipid microspheres (SLM) of octyl methoxy cinnamate (2-ethylhexyl-p-methoxy cinnamate; OMC) to achieve controlled release, decrease penetration of this UV absorber from skin and improve its photostability. The influence of the carrier on the rate of release was studied in vitro with a cellulose acetate membrane and in vivo from excised rat skin with Franz diffusion cells. The release rate was decreased by up to 13-80% with the SLM formulation. In vivo, penetration of OMC into skin was investigated by HPLC method. It was found out that the rate of penetration is significantly dependent upon the formulation and could be decreased by up to 77% in SLM formulations. When different topical vehicles were compared, OMC was released and penetrated into rat skin more quickly and in greater amount from vehicles containing free OMC than in SLM form. Additionally, photostability was shown to be improved in SLM form.

Inclusion of ketoprofen with skimmed milk by freeze-drying.

Ketoprofen is a non-steroidal anti-inflammatory drug which is not soluble in water and creates gastrointestinal problems. In order to improve the solubility of the drug in water and enhance its dissolution rate, physical mixture (PM) and inclusion (IC) of ketoprofen with skimmed milk (SM) were prepared and investigated. Enhancement of solubility of ketoprofen was obtained by preparing its IC with SM which can be used because of its amino acid and surface active agents content and can also be used for treatment of gastric disturbance. Lyophilization technique was used to prepare the IC. Results obtained showed that the solubility of IC of ketoprofen with SM was almost four times greater than the solubility of the plain drug. Data from the dissolution rate determination have also indicated that IC of ketoprofen with SM significantly improved the dissolution rate of the drug compared with PM and the plain form. Differential scanning calorimetry (DSC), X-ray powder diffraction and scanning electron microscopic (SEM) analysis revealed the formation of IC of ketoprofen with SM.

Formulation and characterization of solid lipid nanoparticles, nanostructured lipid carriers and nanoemulsion of lornoxicam for transdermal delivery

Abstract Solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC) and nanoemulsion (NE) of lornoxicam (LRX) were prepared for the treatment of painful and inflammatory conditions of the skin. Compritol® 888 ATO, Lanette® O and oleic acid were used as solid and liquid lipids. SLN, NLC and NE were found physically stable at various temperatures for 6 months. Case I diffusional drug release was detected as the dominant mechanism indicating Fickian drug diffusion from nanoparticles and nanoemulsion. The highest rate of drug penetration through rat skin was obtained with NE followed by NLC, SLN and a gel formulation. Nanoformulations significantly increased drug penetration through rat skin compared to the gel (p < 0.05). Thus, SLN, NLC and NE of LRX can be suggested for relieving painful and inflammatory conditions of the skin

Effect of Vehicles on Release of Meloxicam from Various Topical Formulations

This article evaluates the effect of various vehicles (O/W, W/O and two W/O/W emulsions and a hydrogel) on meloxicam release. One of W/O/W emulsions was named W/O/W-C containing Carbopol ® 934 as a gelling agent in its outer aqueous phase. Release of drug through cellulose acetate membrane was studied by using Franz-type diffusion cells. Hydrogel formulation gave the highest release with a significant difference followed by W/O/W, O/W, W/O/W-C and W/O emulsions. Increase in amount of oil phase resulted in slower drug release strictly indicating importance of lipophility of vehicle on release of lipophilic drugs like MX. Incorporation of MX in hydrogel increased the released amount by up to 20 times when compared with the other formulations. Increase in viscosity of the formulations was also followed the same order. Release study was performed by using UV spectroscopy. Furthermore, the determination method of MX was validated through the following performance criteria: linearity, intra-day and inter-day precision, accuracy, specifity and recovery. This method was proved as precise and accurate determination of MX in multi-component pharmaceutical preparations besides colorimetric methods.

Effects of a Thermosensitive In Situ Gel Containing Mometasone Furoate on a Rat Allergic Rhinitis Model

Background Mometasone furoate, one of the second generation intranasal corticosteroids, is currently used in suspension form due to its poor solubility. However, this is not favorable for nasal application because of the rapid elimination of the instilled drug from the nasal cavity by mucociliary clearance and delayed onset of action due to the slow dissolution of drug in suspension. Objective The aim of this study was to determine the antiallergic effects of mucoadhesive thermosensitive in situ gel containing mometasone furoate that we developed previously to prolong the contact between the drug and nasal mucosa and to prevent drainage of the formulation in an ovalbumin-induced rat model of allergic rhinitis. Methods An experimental allergic rhinitis model was developed in female Wistar albino rats by intraperitoneal injection of ovalbumin every 2 days for 14 days followed by its repeated intranasal instillation for 7 consecutive days. Intranasal instillation of ovalbumin was continued every other day for 14 days. Mometasone furoate in situ gel (5 μg/10 µl), mometasone furoate suspension (5 μg/10 µl), and physiological saline (10 µl) were administered into the bilateral nasal cavities from day 22 to day 35. Antiallergic effects were evaluated through histopathological evaluation, analysis of ovalbumin-specific serum immunoglobulin E, and a symptom score. Results Mometasone furoate in situ gel significantly decreased the nasal symptoms and ovalbumin-specific serum immunoglobulin E level as compared with mometasone furoate suspension and physiological saline. Additionally, inflammatory histological symptoms such as mucosal edema, vascular dilatation, eosinophil infiltration, and loss of cilia within the nasal mucosa of allergic rhinitis model rats were remarkably improved with the treatment of mometasone furoate in situ gel. Conclusion These results suggest that mometasone furoate in situ gel has a better therapeutic potential for the treatment of allergic rhinitis compared to mometasone furoate suspension.

3 – Porous scaffolds

Tissue engineering (TE) is a discipline that aims to generate functional tissue by using porous scaffolds serving as a three-dimensional model for initial cell attachment and growth, which is necessary for the regeneration of damaged or functionally insufficient tissues. Production of biodegradable porous scaffolds with desired pore properties depends on suitable scaffolding material selection, the appropriate production techniques, and the applied process. This chapter briefly introduces the concept of TE and explains the relation between materials science and TE. The effect of chemical and structural properties of scaffolds on the cell adhesion, proliferation, migration, and differentiation is to be considered. The most commonly used synthetic and naturally derived scaffold materials and various production technologies for scaffolding (scaffold) are detailed. Furthermore, limitations and specific features of each technology are discussed.