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The major drawback of the eye drops is rapid elimination of drug from the precorneal region, thus ensuing poor bioavailability as well as therapeutic efficacy. To conquer these limitations, a pH triggered in situ gel was developed for sustained delivery of levofloxacin. Two polymers namely hydroxypropyl methylcellulose (HPMC) and sodium alginate along with the boric acid buffer were used to formulate the in situ gel. Based on the various physicochemical evaluation parameters like pH, clarity and gelling capacity placebo formulations were selected and further characterized for viscosity, in vitro release, ex vivo corneal permeation, and histopathological studies. The optimized in situ gel (F28) showed sustained release of 93 ± 4.23% for 24 h and cumulative drug permeation of 71.81 ± 4.7% for 72 h. Additionally, ocular irritation study and histopathology of the formulation treated cornea confirm the non-irritancy of the optimized formulation. Based on all the above performed studies, it can be concluded that the in situ gel would present a fruitful alternative for the ocular infections.

The oral delivery of hydrophobic drug presents a major challenge because of the low aqueous solubility of such compounds. Self-emulsifying/microemulsifying drug delivery system (SEDDS/SMEDDS), which are isotropic mixtures of oils, surfactants, solvents and co-solvents/surfactants, can be used for the design of formulations in order to improve the oral absorption of highly lipophilic drug compounds. The efficiency of oral absorption of said drug from such type of formulation depends on many formulation-related parameters, such as surfactant concentration, oil/surfactant ratio, polarity of the emulsion, droplet size and charge, all of which in essence determine the self-emulsification ability. Thus, only very specific pharmaceutical excipient combinations will lead to efficient self-emulsifying systems. With the growing interest in this field, there is an increasing need for guidelines in excipient selection to obtain effective delivery system with improved bioavailability. The aim of this review is to present the recent approaches in selecting the most appropriate lipid system(s); methods for its characterization and role of various excipients for improved delivery of dosage form.

Context: Humic acid (HA) is omnipresent in natural organic matter that is a macromolecular, negatively charged polyelectrolyte that contains a hydrophobic core. It is also present in a significant amount in Shilajit (used frequently in traditional medicines), which is used in this study as a source of extraction. HA is evaluated for the oral drug delivery of carbamazepine (CBZ)., Objective: HA is used in this study to increase the dissolution, intestinal permeation, and pharmacodynamic response of CBZ (bio pharmaceutics classification system (BCS) II) by the technique of complexation and other related mechanism reported with humic substances., Methods: Different complexation techniques were explored in this study for the entrapment of CBZ, which was authenticated by molecular modeling and conformational analysis. These were further characterized using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). Solubility analysis and dissolution release profile were carried out to access the in vitro parameters. For ex vivo studies, rat gut intestinal permeability was done. And finally pharmacodynamic evaluation (maximal electroshock method) was carried out for optimized complexes., Results: Molecular modeling approach and instrumental analysis (DSC, XRD, and FT-IR) confirmed the entrapment of CBZ inside the complexing agent. Increased solubility (∼1742%), sustained release (∼78%), better permeability (∼3.5 times), and enhanced pharmacodynamic responses conferred the best to 1:2 freeze dried (FD) and then 1:2 kneading (KD) complexes compared with pure CBZ., Conclusion: Now it could be concluded that HA may be tried as a complexing agent for antiepileptic drug and other classes of low water-soluble drug.