Comparative Study of In Situ Gel Formulation Based on the Physico-Chemical Aspect: Systematic Review

Abstract

In recent years, in situ gel delivery systems have received a great deal of attention among pharmacists. The in situ gelation mechanism has several advantages over ointments, the most notable being the ability to provide regular and continuous drug delivery with no impact on visual clarity. Bioavailability, penetration, duration, and maximum medication efficacy are all improved by this mechanism. Our review systematically synthesizes and discusses comparisons between three types of in situ gelling system according to their phase change performance based on the physicochemical aspect from publications indexed in the Pubmed, ResearchGate, Scopus, Elsevier, and Google Scholar databases. An optimal temperature-sensitive in situ gelling solution must have a phase change temperature greater than ambient temperature (25 °C) to be able to be readily delivered to the eye; hence, it was fabricated at 35 °C, which is the precorneal temperature. In a pH-sensitive gelling system, a gel develops immediately when the bio-stimuli come into contact with it. An in situ gelling system with ionic strength-triggered medication can also perhaps be used in optical drug-delivery mechanisms. In studies about the release behavior of drugs from in situ gels, different models have been used such as zero-order kinetics, first-order kinetics, the Higuchi model, and the Korsmeyer-Peppas, Peppas-Sahlin and Weibull models. In conclusion, the optimum triggering approach for forming gels in situ is determined by a certain therapeutic delivery application combined with the physico-chemical qualities sought.

Tailoring Risperidone-Loaded Glycethosomal In Situ Gels Using Box–Behnken Design for Treatment of Schizophrenia-Induced Rats via Intranasal Route

“…It was noted that gel spreadability was inversely proportional with the viscosity of various in situ gel preparations (Table 5). The produced G5 formulation exhibited high spreadability (3.26 ± 0.05 cm) and low viscosity (11,133.33 ± 47.14 cP) compared to G2 and G9. Similar findings were presented by Morsy et al, 2019 [50].…”

“…The term "in situ gel systems" pertains to polymer solutions that can be supplied in liquid form and afterwards undergo a phase transition to become semisolid gels when exposed to a physiological stimuli [11]. There are several mechanisms that might result in the development of in situ gels, including pH variation, ionic cross-linkage, and temperature variation [11]. Their fluid-like fluidity before coming into contact with the nasal mucosa can make them easier to administer and enable for a precise drug dosing.…”

Investigating Bioactive-Glass-Infused Gels for Enamel Remineralization: An In Vitro Study

“…This test is commonly employed for various medicinal products in gel form [24]. The methodology for this investigation was adapted from the article and the American Pharmacopeia [25,26]. A magnetic stirrer was placed in a 100 mL glass beaker, which was then filled with 40 mL of distilled water.…”