Vitamin D (VD) is a fat-soluble prohormone well known for its role in regulating calcium and phosphate metabolism. It has been clinically used for many years to prevent rickets in children, osteomalacia, and osteoporosis in adults. VD insufficiency is a common medical condition, and many supplements are available in the market in order to increase serum 25-hydroxy VD levels to recommended amounts. Over the course of the last decades, it has become increasingly clear that calcitriol, an active form of VD, regulates multiple cellular processes with effects on normal and malignant cell growth and differentiation, and on the immune and cardiovascular function. Increasing evidence supports the role of the VD system in cancer prevention and therapy. Due to many pleiotropic and beneficial effects in extra-skeletal disorders, VD has gained potential and become an interesting active for encapsulation into drug delivery systems. The purpose of this review is to present the diversity of drug delivery systems that have been reported for VD or VD derivatives in an orderly manner across the following categories: Oral administration, application on the skin, cancer prevention/therapy, and other diseases or routes of administration.

Pharmaceutical products containing non-steroidal anti-inflammatory drugs (NSAIDs) are among the most prescribed topical formulations used for analgesic and antirheumatic properties. These drugs must overcome the skin barrier to cause a therapeutic effect. Human skin has been widely used as a model to study in vitro drug diffusion and permeation, however, it suffers from many limitations. Therefore, to perform in vitro permeation test (IVPT), we used a Strat-M^® membrane with diffusion characteristics well-correlated to human skin. This study’s objective was to optimize the IVPT conditions using Plackett–Burman experimental design for bio-predictive evaluation of the in vitro permeation rates of five non-steroidal anti-inflammatory drugs (diclofenac, etofenamate, ibuprofen, ketoprofen, naproxen) across Strat-M^® membrane from commercial topical formulations. The Plackett–Burman factorial design was used to screen the effect of seven factors in eight runs with one additional center point. This tool allowed us to set the sensitive and discriminative IVPT final conditions that can appropriately characterize the NSAIDs formulations. The permeation rate of etofenamate (ETF) across the Strat-M^® membrane was 1.7–14.8 times faster than other NSAIDs from selected semisolids but 1.6 times slower than the ETF spray formulation.

Background: Ampicillin (AMP) is frequently administered parenterally in critically ill patients with meningitis or endocarditis. Many of them require parallel infusion of total parenteral nutrition (TPN) admixtures. The aim of the study was to determine the physicochemical stability of AMP in TPN admixtures. Methods: AMP was added to two formulations of TPN admixtures differing in the lipid emulsion (Lipofundin^® MCT/LCT 20% or LIPIDem^®). Samples were stored at 4 ± 1 °C with light protection, and at 25 ± 1 °C with and without light protection to assess the impact of temperature and light on formulation stability. Every 24 h the pH, zeta potential, mean droplet diameter (MDD) of a lipid emulsion, and AMP concentration using HPLC method were determined. The assessment of stability and compatibility of TPN admixtures with vitamins and trace elements was carried out immediately after preparation and after 24 h of storage. Results: The addition of AMP as well as vitamins and trace elements to the TPN admixtures did not affect their physical stability. An increase in the pH value of approx. 0.6 and reduction of zeta potential were observed. The MDD of the lipid emulsions was below the limit of 500 nm (dynamic light scattering (DLS) method) and no fat droplets greater than 525 nm were observed (light diffraction (LD) method). The content of AMP after the first 24 h was within the acceptable limit of 90% for TPN admixtures stored at 4 ± 1 °C and 25 ± 1 °C with light protection. Conclusions: The results showed that co-administration of AMP in the same bag with TPN admixture at the tested dose is possible when used ex tempore and with light protection.