Graphical abstract Polymer microneedle promotes the delivery of chemical and biological drugs through the skin.

Self-emulsifying drug delivery system (SEDDS) is an isotropic mixture of lipid, surfactant and co-surfactant, which forms a fine emulsion when comes in contact of an aqueous medium with mild agitation. SEDDS is considered as a potential platform for oral delivery of hydrophobic drug in order to overcome their poor and irregular bioavailability challenges. In spite of fewer advantages like improved solubility of drug, bypassing lymphatic transport etc., SEDDS faces different controversial issues such as the use of appropriate terminology (self-microemulsifying drug delivery system; SMEDDS or self-nanoemulsifying drug delivery system; SNEDDS), presence of high amount of surfactant, correlation of in vitro model to in vivo studies, lack of human volunteer study and effect of conversion of SEDDS to final administrable dosage form on pharmacokinetic behavior of the drug. In this review, potential issues or questions on SEDDS are identified and summarized from the pharmacokinetic point of view. Primarily this review includes the conflict between the influences of droplet size, variation in correlation between in vitro lipolysis or ex-vivo intestinal permeation and pharmacokinetic parameters, variation in in vivo results of solid and liquid SEDDS, and potential challenges or limitation of pharmacokinetic studies on human volunteers with orally administered SEDDS. In the past decades, hundreds of in vivo studies on SEDDS have been published. In the present study, only the relevant article on in vivo pharmacokinetic studies with orally administered SEDDS published in past 5-6 years are analyzed for an up to date compilation. KeywordsPoor bioavailability, self-nanoemulsifying delivery system, self-microemulsifying delivery system, in vitro lipolysis, pharmacokinetic of SEDDS History

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Objective: Paracetamol is a common antipyretic and analgesic medicine used in childhood illness by parents and physicians worldwide. Paracetamol has a bitter taste that is considered as a significant barrier for drug administration. This study aimed to develop an oral dosage form that is palatable and easy to swallow by pediatric patients as well as to overcome the shortcomings of liquid formulations. Methods: The paracetamol was encapsulated in beads, which were prepared mainly from alginate and chitosan through electrospray technique. The paracetamol beads were sprinkled on the instant jelly prepared from glycine, ι-carrageenan and calcium lactate gluconate. The paracetamol instant jelly characteristics, in terms of physical appearance, texture, rheology, in vitro drug release and palatability were assessed on a human volunteer. Results: The paracetamol instant jelly was easily reconstituted in 20 mL of water within 2 min to form jelly with acceptable consistency and texture. The jelly must be ingested within 30 min after reconstitution to avoid the bitter taste. The palatability assessment carried out on 12 human subjects established the similar palatability and texture of the paracetamol instant jelly dosage comparable to the commercial paracetamol suspension and was found to be even better in overcoming the aftertaste of paracetamol. Conclusion: Such findings indicate that paracetamol instant jelly will compensate for the use of sweetening and flavoring agents as well as develop pediatric dosage forms with limited undesired excipients.

Telmisartan suffers from low oral bioavailability due to its poor water solubility. The research work presents a formulation of solid dispersed (SD) telmisartan formulation as a ternary mixture of a drug, a polymeric carrier (poly(vinylpyrrolidone) (PVP) K30), and an alkalizer (Na 2 CO 3 ). The preparation method, which was lyophilization of an aqueous solution containing the ingredients, was free from any organic solvent. The developed SD formulations resulted in a significant improvement in in vitro dissolution (>90% drug dissolution in 15 min) compared to pure telmisartan. Solid-state characterization by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) studies indicated the conversion of crystalline telmisartan into an amorphous form. Fourier transform infrared (FTIR) spectroscopy revealed the drug–polymer interaction that was responsible for reducing the chances of recrystallization. A short-term stability study showed that selected SD formulations were stable in terms of in vitro dissolution and retained their amorphous structure in ambient and accelerated conditions over 2 months. Selected formulations (drug/PVP K30/Na 2 CO 3 as 1:1:2 or 1:2:2 weight ratio) resulted in >2.48 times relative oral bioavailability compared to marketed formulations. It was considered that the incorporation of an alkalizer and a hydrophilic polymer, and amorphization of telmisartan by lyophilization, could enhance in vitro dissolution and improve oral bioavailability.