Poloxamer 407 as a solubilising agent for tolfenamic acid and as a base for a gel formulation

Cocrystals of Fenamic Acids with Nicotinamide

“…The relative strength of the acids as hydrogen bond donors can be estimated from their pK a values. 5,[35][36][37][38][39] It is clear from Table 4 that differences in pK a and thus differences in the hydrogen bonding ability of the acids do not explain the different outcomes of the screening experiments. The conformation of the fenamic acids shows a large variation in their crystal structures (Table 5), but the different conformations can not be linked directly to the different compositions and stabilities of the cocrystals.…”

“…2 A common property of fenamic acids is their low aqueous solubility, which has been suggested to be a key factor in restricting their bioavailability. 3,4 Numerous formulation approaches have been employed historically to increase solubility (e.g., use of polymers, 5 cyclodextrins, 6 layered hydroxides, 7 nanoparticulates, 8 salts 9 and amorphous materials 10 ). Cocrystallization of active pharmaceutical ingredients (APIs) with water soluble guests is an emerging strategy to increase kinetic solubility and, thus, bioavailability.…”

Poly(ethylene oxide)–Poly(propylene oxide)-Based Copolymers for Transdermal Drug Delivery: An Overview

“…The results indicate the possibility of both systemic and topical administration of tolfenamic acid by means of aqueous solutions or gels containing Poloxamer 407 in an adequate concentration. The solubilization process was spontaneous and exothermic, as indicated by thermodynamic parameters [8].…”

“…Though their potential drawbacks include weak mechanical strength and rapid erosion (i.e., dissolution from the surface) [44,45], poloxamer gels have been shown to provoke neither skin irritation nor sensitivity, thus confirming its good tolerability and useful in topical formulations [1,8,44,46]. Among these, Poloxamer 407, also known as Lutrol or Pluronic F127, is an ABA-type triblock copolymer consisting of PEO units (A = 70%) and PPO units (B = 30%), which is transformed from a low-viscosity solution to a semisolid gel upon heating to body temperature at concentrations of > 20 % [47,48], have become the subject of growing interest for use in the formulation of dosage forms owing to their low toxicity and ability to form a clear solution or gel in aqueous media [8,49]. To increase their applicability, poloxamers can be physically or chemically modified by different polymenrs [47,50,51].…”

“…Studies on PEO-PPO-based polymeric micelles for transdermal drug delivery have been widely carried out with Poloxamer 407 (Pluronic F127) and these studies mostly focused on small drug molecules in order of anti-inflammatory [8][9][10][11][12][13][14][15][16][17][18][19], analgesic [20], local anesthetic [21] and cardiac effectiveness [19,[22][23][24] and rarely focused on big molecules such as arginine vasopressin (AVP) and insulin [25,26].…”