Comparative anti-ulcerogenic study of pantoprazole formulation with and without sodium bicarbonate buffer on pyloric ligated rat

Compounding of Liquid and Solid Dose Adjustable Formulations with Pantoprazole: Comparison of Stability, Applicability and Suitability

Pantoprazole is a model substance that requires dosage form adjustments to meet the needs of all patients. Pediatric pantoprazole formulations in Serbia are mostly compounded as capsules (divided powders), while in Western Europe liquid formulations are more common. The aim of this work was to examine and compare the characteristics of compounded liquid and solid dosage forms of pantoprazole. Three syrup bases were used: a sugar-free vehicle for oral solution (according to USP43-NF38), a vehicle with glucose and hydroxypropyl cellulose (according to the DAC/NRF2018) and a commercially available SyrSpend Alka base. Lactose monohydrate, microcrystalline cellulose and a commercially available capsule filler (excipient II, composition: pregelatinized corn starch, magnesium stearate, micronized silicon dioxide, micronized talc) were used as diluents in the capsule formulations. Pantoprazole concentration was determined by the usage of the HPLC method. Pharmaceutical technological procedures and microbiological stability measurements were performed according to the recommendations of the EP10. Although dose appropriate compounding with pantoprazole is suitable using both liquid vehicles as well as solid formulations, chemical stability is enhanced in solid formulation. Nevertheless, according to our results, if liquid formulation is a pH adjusted syrup, it could be safely kept in a refrigerator for up to 4 weeks. Additionally, liquid formulations could be readily applied, while solid formulation should be mixed with appropriate vehicles with higher pH values.

Effects of Manufacturing Methods on Dissolution and Absorption of Ketoconazole in the Presence of Organic Acid as a pH Modifier

Poorly water-soluble compounds have a potential risk of low and variable bioavailability caused by incomplete dissolution. Incorporation of organic acids as pH modifiers is effective method for solubility enhancement of basic compounds and requires no special technique and equipment. The purpose of this study was to evaluate the effect of manufacturing method on the extent of drug solubility enhancement. We successfully prepared the granules and tablets containing ketoconazole (KZ), which is weakly basic, as a model compound and citric acid as a pH modifier using conventional wet and dry granulations. KZ solubility under non-sink condition was enhanced with supersaturation using both wet and dry granulations. High-shear granulation was the most effective method in terms of KZ dissolution enhancement, because both an intimate contact and strong bonding between KZ and incorporated acid were achieved. KZ dissolved amount from the granules prepared by high-shear granulation was about eight times higher than that from the granules without the acid. The granulation involved to suppress a diffusion of acid dissolved, leading to the effectively maintained supersaturation state. The bioavailability of KZ after oral administration to rats was improved by applying high-shear granulation with citric acid independent of gastrointestinal pH. The granules prepared by high-shear granulation showed the bioavailability about 1.7-fold higher than that of the physical mixture in rats with and without neutralization of stomach. As a result, both the dissolution and absorption rates of KZ after oral administration were enhanced using conventional manufacturing technology.

A study of antimicrobial activity, acute toxicity and cytoprotective effect of a polyherbal extract in a rat ethanol-HCl gastric ulcer model

Background

The decoction of the aerial parts of Rhynchosia recinosa (A.Rich.) Bak. [Fabaceae] is used in combination with the stem barks of Ozoroa insignis Del. (Anacardiaceae), Maytenus senegalensis (Lam.) Excell. [Celastraceae] Entada abyssinica Steud. ex A.Rich [Fabaceae] and Lannea schimperi (Hochst.)Engl. [Anacardiaceae] as a traditional remedy for managing peptic ulcers. However, the safety and efficacy of this polyherbal preparation has not been evaluated. This study reports on the phytochemical profile and some biological activities of the individual plant extracts and a combination of extracts of the five plants.

Methods

A mixture of 80% ethanol extracts of R. recinosa, O. insignis, M. senegalensis, E. abyssinica and L. schimperi at doses of 100, 200, 400 and 800 mg/kg body wt were evaluated for ability to protect Sprague Dawley rats from gastric ulceration by an ethanol-HCl mixture. Cytoprotective effect was assessed by comparison with a negative control group given 1% tween 80 in normal saline and a positive control group given 40 mg/kg body wt pantoprazole. The individual extracts and their combinations were also tested for antibacterial activity against four Gram negative bacteria; Escherichia coli (ATCC 25922), Salmonella typhi (NCTC 8385), Vibrio cholerae (clinical isolate), and Klebsiella pneumoniae (clinical isolate) using the microdilution method. In addition the extracts were evaluated for brine shrimp toxicity and acute toxicity in mice. Phytochemical tests were done using standard methods to determine the presence of tannins, saponins, steroids, cardiac glycosides, flavonoids, alkaloids and terpenoids in the individual plant extracts and in the mixed extract of the five plants.

Results

The combined ethanolic extracts of the 5 plants caused a dose-dependent protection against ethanol/HCl induced ulceration of rat gastric mucosa, reaching 81.7% mean protection as compared to 87.5% protection by 40 mg/kg body wt pantoprazole. Both the individual plant extracts and the mixed extracts of 5 plants exhibited weak to moderate antibacterial activity against four G-ve bacteria. Despite Ozoroa insignis being toxic to mice at doses above 1000 mg/kg body wt, the other plant extracts and the combined extract of the 5 plants were tolerated by mice up to 5000 mg/kg body wt. The brine shrimp test results showed the same pattern of toxicity with Ozoroa insignis being the most toxic (LC₅₀ = 10.63 μg/ml). Phytochemical tests showed that the combined extract of the five plants contained tannins, saponins, steroids, cardiac glycosides, flavonoids and terpenoids. Flavonoids, tannins and terpenoids are known to have antioxidant activity.

Conclusion

The combined extract of the five plants exhibited a dose-dependent protective activity in the rat ethanol-HCl gastric ulcer model. The extracts also exhibited weak antibacterial activity against four Gram negative bacteria and low acute toxicity in mice and brine shrimps. Although the results support claims by traditional healers who use a decoction of the five plants for treatment of peptic ulcers, more models of gastric ulceration and proper animal toxicity studies are needed to validate possible clinical use of the polyherbal extract. It is also evident that the doses of the crude extracts showing protection of the gastric mucosa are too large for realistic translation to direct clinical application, but further studies using bioassay guided fractionation are important to either identify more practical fractions or active compound/s.

Gastroprotective Efficacy of Coenzyme Q10 in Indomethacin-Induced Gastropathy: Other Potential Mechanisms

Though recently the mitochondrial bioenergetic coenzyme (Co)Q10 has been shown to protect against indomethacin-induced gastric ulceration, yet the full mechanistic cassettes have not been investigated. Therefore, the current investigation assessed further gastroprotective mechanisms of CoQ10 using the indomethacin-induced gastropathy model. While CoQ10 was administered at 3 dose levels to male Wistar rats, the proton pump inhibitor, pantoprazole, was given at 4 dose levels ahead of pyloric ligation and indomethacin administration. Indomethacin evoked gastric ulcerations that were associated by decreased gastric mucosal nitric oxide and glutathione levels. The NSAID reduced gastric volume and mucin content, but increased titratable acidity, acid output, and peptic activity. CoQ10, especially at the higher dose levels, as well as pantoprazole pretreatments reverted almost all diversions induced by the NSAID to different extends. Moreover, preadministration with the nonselective nitric oxide synthase inhibitor, L-NAME, boosted ulcer formation that was associated by suppression of gastric mucosal nitric oxide in CoQ10 and pantoprazole-treated groups. The current investigation shows that CoQ10 guards against gastric ulceration via its partial inhibition of titratable acidity and peptic activity, as well as enhancement of mucin secretion due to both gastric mucosal nitric oxide and glutathione replenishment, especially at the higher dose levels.