Injectable lipid emulsions, for decades, have been clinically used as an energy source for hospitalized patients by providing essential fatty acids and vitamins. Recent interest in utilizing lipid emulsions for delivering lipid soluble therapeutic agents, intravenously, has been continuously growing due to the biocompatible nature of the lipid-based delivery systems. Advancements in the area of novel lipids (olive oil and fish oil) have opened a new area for future clinical application of lipid-based injectable delivery systems that may provide a better safety profile over traditionally used long- and medium-chain triglycerides to critically ill patients. Formulation components and process parameters play critical role in the success of lipid injectable emulsions as drug delivery vehicles and hence need to be well integrated in the formulation development strategies. Physico-chemical properties of active therapeutic agents significantly impact pharmacokinetics and tissue disposition following intravenous administration of drug-containing lipid emulsion and hence need special attention while selecting such delivery vehicles. In summary, this review provides a broad overview of recent advancements in the field of novel lipids, opportunities for intravenous drug delivery, and challenges associated with injectable lipid emulsions.

The objective of the present research was to evaluate the physicochemical characteristics of berberine chloride and to assess the complexation of drug with 2-hydroxypropyl-β-cyclodextrin (HPβCD), a first step towards solution dosage form development. The parameters such as log P value were determined experimentally and compared with predicted values. The pH-dependent aqueous solubility and stability were investigated following standard protocols at 25°C and 37°C. Drug solubility enhancement was attempted utilizing both surfactants and cyclodextrins (CDs), and the drug/CD complexation was studied employing various techniques such as differential scanning calorimetry, Fourier transform infrared, nuclear magnetic resonance, and scanning electron microscopy. The experimental log P value suggested that the compound is fairly hydrophilic. Berberine chloride was found to be very stable up to 6 months at all pH and temperature conditions tested. Aqueous solubility of the drug was temperature dependent and exhibited highest solubility of 4.05 ± 0.09 mM in phosphate buffer (pH 7.0) at 25°C, demonstrating the effect of buffer salts on drug solubility. Decreased drug solubility was observed with increasing concentrations of ionic surfactants such as sodium lauryl sulfate and cetyl trimethyl ammonium bromide. Phase solubility studies demonstrated the formation of berberine chloride-HPβCD inclusion complex with 1:1 stoichiometry, and the aqueous solubility of the drug improved almost 4.5-fold in the presence of 20% HPβCD. The complexation efficiency values indicated that the drug has at least threefold greater affinity for hydroxypropyl-β-CD compared to randomly methylated-β-CD. The characterization techniques confirmed inclusion complex formation between berberine chloride and HPβCD and demonstrated the feasibility of developing an oral solution dosage form of the drug.

In today’s pharmaceutical arena, it is estimated that more than 40% of new chemical entities produced during drug discovery efforts exhibit poor solubility characteristics. However, over the last decade hot-melt extrusion (HME) has emerged as a powerful processing technology for drug delivery and has opened the door to a host of such molecules previously considered unviable as drugs. HME is considered to be an efficient technique in developing solid molecular dispersions and has been demonstrated to provide sustained, modified and targeted drug delivery resulting in improved bioavailability. This article reviews the myriad of HME applications for pharmaceutical dosage forms such as tablets, capsules, films and implants for drug delivery through oral, transdermal, transmucosal, transungual, as well as other routes of administration. Interest in HME as a pharmaceutical process continues to grow and the potential of automation and reduction of capital investment and labor costs have made this technique worthy of consideration as a drug delivery solution.

Purpose The objective of the present study was to formulate indomethacin (IN)-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) and to investigate their potential use in topical ocular delivery. Methods IN SLNs (0.1% w/v) and NLCs (0.8% w/v) were prepared, characterized and evaluated. Their in vitro release and flux profiles across the cornea and sclera-choroid-RPE (trans-SCR) tissues and in vivo ocular tissue distribution were assessed. Furthermore, chitosan chloride (CS) (mol. wt. < 200 kDa), a cationic and water-soluble penetration enhancer, was used to modify the surface of the SLNs, and its effect was investigated through in vitro transmembrane penetration and in vivo distribution tissue studies. Results For the IN-SLNs, IN-CS-SLNs and IN-NLCs, the particle size was 226 ± 5, 265 ± 8, and 227 ± 11 nm, respectively; the zeta potential was −22 ± 0.8, 27 ± 1.2, and −12.2 ± 2.3 mV, respectively; the polydispersity index (PDI) was 0.17, 0.30, and 0.23, respectively; and the entrapment efficiency (EE) was 81 ± 0.9, 91.5 ± 3.2 and 99.8 ± 0.2%, respectively. The surface modification of the SLNs with CS increased the ocular penetration of IN. The NLCs maintained significantly higher IN concentrations in all ocular tissues tested compared to the other formulations evaluated in vivo. Conclusion The results suggest that lipid-based particulate systems can serve as viable vehicles for ocular delivery. The NLC formulations demonstrated increased drug loading capability, entrapment and delivery to anterior and posterior segment ocular tissues.