An Experimental Comparison of the Analgesic and Anti-Inflammatory Effects of Safflower Oil, Benzydamine HCl, and Naproxen Sodium.

The study aims to establish how feasible a natural therapy option (safflower oil) is in the treatment of postoperative pain. Naproxen sodium has already been experimentally proven to be effective for this purpose. Accordingly, the analgesic and anti-inflammatory effects of safflower oil were compared with those obtained with benzydamine HCl and naproxen sodium. Forty-two, healthy, adult female rats of Wistar albino species were divided at random into six groups of seven rats. The intervention allocation was as follows: Group No. 1-physiological saline 0.9%; Group No. 2-safflower oil 100 mg/kg; Group No. 3-safflower oil 300 mg/kg; Group No. 4-benzydamine HCl 30 mg/kg; Group No. 5-benzydamine HCl 100 mg/kg; and Group No. 6-naproxen sodium 10 mg/kg. Following allocation of treatment, pain was induced experimentally and tested in various ways (hot plate test, tail-pinching test, and writhing test) and the efficacy of each treatment in providing peripheral and central analgesia was evaluated. The second stage consisted of providing different treatments to four groups (groups 7-10) of seven rats each, chosen at random. The allocations were as follows: Group No. 7-physiological saline 0.9%; Group No. 8-safflower oil 300 mg/kg; Group No. 9-benzydamine HCl 100 mg/kg; and Group No. 10-naproxen sodium 10 mg/kg. To create experimental inflammation, 2% formaldehyde was injected into the experimental animal's paw and the resulting edema was measured and recorded for a 10-day period. Edema inhibition was calculated as a percentage. The rats were sacrificed and the paw and stomach dissected for histopathological examination. The data were used for statistical analysis, using the Shapiro-Wilk, Kruskal-Wallis H test, and two-way analysis of variance. In the tail-pinching test, it was determined that a 300 mg/kg dose of safflower oil shows central spinal analgesic efficacy and this effect is close in magnitude to 10 mg/kg of the reference material, naproxen sodium. In the squirming test, it was observed that the 100 and 300 mg/kg doses of safflower oil had a peripheral analgesic effect when compared with the serum physiological (placebo) group. The peripheral efficacy of 300 mg/kg safflower oil was found to approximate that of 10 mg/kg naproxen sodium. In rats treated with benzydamine HCl 100 mg/kg, similar peripheral analgesic efficacy to naproxen sodium 10 mg/kg was noted. In the hot plate test, no difference in the analgesic efficacy between the various agents was found. The change in inhibition of edema between the 1st and 10th days was most marked in rats receiving naproxen sodium 10 mg/kg. A significant difference was determined in the safflower oil 300 mg/kg and benzydamine HCl 100 mg/kg groups (P < .001). Regarding histopathology findings in the rat paw, significant differences were seen in venous congestion between placebo and safflower oil 300 mg/kg and in inflammation between the control and benzydamine HCl 100 mg/kg groups. Regarding the histopathology findings in the rat stomach, significant differences were observed in venous congestion between placebo and safflower oil 300 mg/kg; in damage to the epithelium between placebo and safflower oil 300 mg/kg and between naproxen sodium 10 mg/kg and safflower oil; and in cell infiltration and development of edema between placebo and safflower oil 300 mg/kg. It is predicted that further research into safflower oil and benzydamine HCl will create opportunities to develop analgesic-anti-inflammatory therapeutics of a novel kind for the treatment of postoperative pain and inflammation.

Thermally sensitive gels based on chitosan derivatives for the treatment of oral mucositis.

The aim of the present work was the development of a thermally sensitive mucoadhesive gel based on chitosan derivatives for the treatment of oral mucositis. Trimethyl chitosan (TMC) and methylpyrrolidinone chitosan (MPC) were considered. They were mixed with glycerophosphate (GP) according to different polymer/GP molar ratios and characterized for gelation properties by means of rheological analysis in comparison with chitosan. The influence of molecular weight and substitution degree (SD) of TMC on gelation temperature and time was investigated. The mucoadhesive properties of the mixtures were also assessed using porcine buccal mucosa. The best properties were shown by TMC with high MW and low SD mixed with GP according to 1:2molar ratio. Such mixture was loaded with benzydamine hydrochloride, an anti-inflammatory drug with antimicrobial properties and subjected to in vitro drug release and wash away test. The formulation based on TMC/GP mixture was able to prolong drug release and to withstand the removal physiological mechanisms. The antimicrobial properties of both vehicle and formulation were investigated. Also in absence of drug, TMC/GP mixture was characterized by antimicrobial properties.

Effects of benzydamine eye drops on the rabbit's eye reaction to surgical, physical, and chemical stimuli.

The effects of benzydamine eye drops on the ocular reaction to different irritating stimuli in rabbits are reported. Benzydamine at the concentration of 0.1% reduces inflammatory tissue changes induced by AgNO3 burning of the cornea and inhibits the blood-aqueous barrier breakdown due to peripheral iridectomy or laser irradiation of the iris. Benzydamine reduces the aqueous PGE2 concentration to a similar extent as a 0.5% commercially available eye drop formulation of piroxicam. This result is in contrast with previous in vitro results demonstrating that benzydamine is devoid of any effects on PG synthesis. The possibility that PGE2 reduction is an indirect effect due to other biochemical activities of benzydamine is discussed. In the normal eye benzydamine manifests a local anaesthetic effect which is not accompanied by irritative changes in the anterior segment of the eye, changes in the intraocular pressure or pupillary size. It is suggested that in the clinical use of benzydamine eye drops the local anaesthetic activity may contribute to reducing both the neurogenic component of ocular inflammation and acute pain following injuries to the eye.

Evidence from two classic irritation tests for an anti-inflammatory action of a natural extract, Echinacina B.

The roots of Echinacea angustifolia (fam. Compositae) were used to obtain an antiphlogistic, immunostimulating and skin repairing extract. On the basis of these potential actions, the extract is used in cosmetic preparations. The aim of this study was to evaluate the anti-inflammatory activity of the extract using different irritation tests. The irritation reaction was induced by application of 0.015 ml of 0.25% croton oil in water to the ears of mice. The raw extract (Echinacina B), topically applied, inhibited oedema both at the maximum (6 hr) and in the decreasing phase (18 hr), and this effect was directly proportional to the doses used. Echinacina B was found to be more potent than the positive control, benzidamine, a topical non-steroidal anti-inflammatory drug. In addition, the extract given iv 1 hr before injection of 0.05 ml of 1% carrageenan into the hind paws of rats inhibited oedema in the histaminic and in the later phases of the phlogistic process. These data show the qualitative value of irritation tests for studying the anti-inflammatory action of a natural plant extract.