[Comparative evaluation of the anionic superdisintegrant incorporation mode on the quality of ranitidine tablets]

The present study was based on the impact of the superdisintegrants incorporation mechanism on the immediate realese of the tablets final performances. The aim was the selection of the working method to obtain Ranitidine 150 mg tablets with the desiderate quality and in reproducible conditions.

MATERIAL AND METHODS

The effect of the incorporation mode of sodium starch glycolate on the aspect, granules size distribution and flowing properties of the lubricated product, and also the weight uniformity, hardness, disintegration, friability, and dissolution of the Ranitidine 150 mg tablets prepared by dry granulation was studied. The addition mode of the disintegrant was realized in three ways: intragranular, extragranular, and distributed equally between the two phases. The distribution range for the tablets weight was established. Relative standard distribution was calculed for the weight and hardness of the uncoated tablets.

RESULTS

The powder flow and, implicit, the weight uniformity of the uncoated tablets was positive influenced by the extragranular incorporation of the superdisintegrant. The disintegration time was identical for all the three disintegrant addition modes, and the hardness and the friability were not significantly influenced by working method, the obtained values were similar. For the developed formulations, the percent of the ranitidine dissolution was high, but higher in the extragranular incorporation.

CONCLUSIONS

For the product quality the extragranular addition mode seemed the best method to incorporate the superdisintegrant.

Optimization of topical gels with betamethasone dipropionate: selection of gel forming and optimal cosolvent system

The purpose of these studies was to develop a 0.05% betamethasone gel characterized by physical-chemical stability and good release properties. The preliminary studies were designed to select the gel-forming agents and the excipients compatible with betamethasone dipropionate. In order to formulate a clear gel without particles of drug substances in suspension, a solvent system for the drug substance was selected. The content of drug substance released, the rheological and in vitro release tests were the tools used for the optimal formulation selection. A stable carbomer gel was obtained by solubilization of betamethasone dipropionate in a vehicle composed by 40% PEG 400, 10% ethanol and 5% Transcutol.

[Formulation by design of experiments of immediate release tablets with metformin hydrochloride and glibenclamide]

The present investigation was based on the latest quality by design principles, using the design of experiments technique. The aim was to attain an immediate release formulation of metformin hydrochloride and glibenclamide and to optimize the delivery of these two different antidiabetic agents within a single-tablet combination.

MATERIALS AND METHODS

Due to the poor flow properties of metformin hydrochloride, in order to attain the dose uniformity, a wet granulation based manufacturing process was used. The prepared tablets were evaluated for the release of metformin hydrochloride and glibenclamide using validated HPLC methods. The similarity factor was calculated, taking into consideration as reference profile the mean in vitro dissolution data of Glucovance. The formulation process was undertaken using a reproducible DoE generated model, attained by the variation of each of the formulation factors on two levels, followed by the filling of the data resulted from the analytical testing of the tablets.

RESULTS

The model was fitted using Partial Least Squares method. For the assessment of the level of fitting, Q2, R2 and Anova tests were performed. The desired drug release pattern can be achieved by using a proper percent of superdesintegrant, by reducing the filler and by the presence of extragranulary added binder.

CONCLUSION

The results have shown that the experimental responses match the statistical generated model and that the investigation is reproducible.

Formulation of creams with betamethasone dipropionate: evaluation of chemical stability

The aim of this study was to investigate how the different excipients influenced the chemical stability of betamethasone dipropionate in creams. The chemical stability was evaluated by analyzing betamethasone related substance content. Transcutol is the excipient ensuring maximum stability to betamethasone. Incompatibilities between betamethasone dipropionate and hexylene glycol were observed. The pH values in the weak acid range confer chemical stability to betamethasone.

Characterization of some extractive fractions isolated from raw Allium cepa L. bulbs

Many recent studies have showed that onion (Allium cepa L.) has antioxidant effect which could be of great importance for prevention and treatment of different diseases: diabetes, cancer, cardiovascular and neurodegenerative disorders. The aim of this study was to investigate the antioxidant capacity of two extracts isolated from fresh onion bulbs: an hydroalcoholic extract (codified EC1) and an aqueous extract (codified EC2).

METHODS

Antioxidant capacity was evaluated by three different assays: DPPH scavenging assay, H2O2, scavenging assay and reducing power assay.

RESULTS

Both investigated extracts possess interesting antioxidant properties which are significantly influenced by their chemical composition.

[Research concerning the characterization of Allium cepa based ointments]

Three topical formulae with Allium cepa L. extract 30% (w/w) were studied for the evaluation of their release profiles of flavonoids and for their potency on experimental wounds on mice. The rates of release were performed under occluded conditions using cellulose acetate membrane. Data obtained from the in vitro release show that the gel formula F1 is the most efficient in the membrane diffusion process. The rate of wound healing was assessed by the contracting ability and the period of epithelization. The most important effect in the contracting ability was noticed in the case of F2 formula.

[Phytochemical and microbiological characterization of two Allium cepa L. extracts in order to include in dermo-cosmetics]

We have obtained two Allium cepa extracts (C1 and C2) which were characterized from chemical and microbiological point of view. The C1 extract is the richest concerning the content in flavonoids, triterpenic acids, amino acids, compounds recognized for their beneficial effects in wound healing. All this data shows us the possibility of using the Allium cepa extracts in the treatment of wounds, scars. As well, the antimicrobial activity of the two extracts was evaluated. The C2 extract was efficient as antimicrobial agent, but there are necessary special preserving conditions.

[Oral disintegrating tablets. A new, modern, solid dosage form]

The pharmaceutical market shows lately an increasing interest in orally disintegrating tablets, due to their good acceptability among certain age categories (ex. elderly, children), and other patients with difficulties in swallowing classic solid dosage forms. Some of the methods of preparing such tablets have gained industrial applicability: molding, lyophilization, direct compression with highly soluble excipients, super disintegrants and/or effervescent systems. Some of the patients have had a good impact on the pharmaceutical market and more improvements are expected in the next few years, with new drugs to be formulated as fast dissolving dosage formulations.

[Antimicrobial activities of organic zinc compounds]

Taking into account the competitive action of zinc towards other ion essential for pathogenic germs metabolism, the complex erythromycin-zinc, zinc salts of sulfamethoxydiazine, sulfanilamide, sulfacetimide, sulfathiazole as well as the Mannich basis of sulfamethoxydiazine were synthetized. The antimicrobial action towards gram-positive, gram-negative pathogens and fungi was tested by the classic diffusiometric method. An increased antimicrobial action for the Mannich basis of sulfamethoxydiazine and for the zinc salt of sulfamethoxydiazine, alone or in association with metronidazole--chemotherapeutic agent used in the infections with anaerobic organisms was found. A significant antimicrobial action was also found for the complex erythromycin-zinc and zinc salts of sulfacetimide and sulfathiazole.

[The effect of a hydrogel with Enzaprost F on labor induction in pregnant women with severe late gestosis]

The authors suggested a new method for preparing the delivery in patients with severe gestosis consisting of local applications of Enzaprost F hydrogel in association with the correction of arterial hypertension in relation with the hemodynamic type. Unlike the previous preparations, in the composition of the hydrogel with prostaglandin F2-alpha, polyvinylpyrrolidone is also included, thus increased adhesive properties and a slower release of prostaglandin resulting. The correction of arterial hypertension depending on the hemodynamic type provided rapid stabilization of patients' condition. The suggested method does not only decrease by 2.4 times the prenatal hospitalization but also reduces with 16.2% the frequency of abdominal delivery in this category of patients.

[Formulations and bioavailability of propyphenazone in lyophilized tablets]

The present work reports some facts about the preparation and release characteristics of the tablets of propiphenazone made by lyophilizing method (lyoc); they are compared with the classic tablets obtained by simple compression. Our substance, the propiphenazone, is a stable one, but we can talk about its poor solubility. Therefore, in order to obtain the lyoc tablets, we chose the method of paste. This tablets had a spongy aspect, with a desaggregation time of 1-2 min.; the latter (classic tablets) were regularly and the desaggregation time in about 9 min. The kinetics of propiphenazone absorbtion would be expected to differ in these structurally-distinct tablets types. Indeed, the concentration was really appreciable for the lyoc tablets after 30 min., with the peak at 60 min.; for the classic tablets the peak was remarkably only after 90 min. The relative bioavailability for these two types of tablets pointed out the differences, confirming the evident advantages for using the lyoc tablets in analgesic, antipyretic therapy.

[Adhesive cutaneous pharmaceutical forms]

The adhesive cutaneous pharmaceutical forms aimed to local action release the drug substance in view of a dermatological, traumatological, antirheumatic, cosmetic action. Two such preparations were obtained and their stability, consistency and pH were determined. The "in vitro" tests of their bioavailability revealed the dynamics of calcium ions release according to the associations of each preparation. The bioavailability determined by evaluating the pharmacological response demonstrated the antiinflammatory action obtained by the association of calcium ions with the components extracted from poplar muds. The therapeutical efficiency of the studied preparations has proved in the treatment of some sport injuries.

[The cutaneous bioavailability of alpha-chymotrypsin from ointments]

In view of improving the cutaneous bioavailability of alpha-chymotrypsin from ointments, the stability of this enzyme in two hydrophile ointment bases, macrogoli and carbopol, was tested. The cutaneous bioavailability of alpha-chymotrypsin in ointments, estimated by determining the anti-inflammatory action, underlines the important role played both by the ointment base and by the enzyme activating substances. By correlating the determinations of alpha-chymotrypsin enzymatic activity with the anti-inflammatory action a correlation between the manifested activity and the active substance stability was noticed.

[Studies reagarding the bioavailability of oxacillin from preconditioned powders]

Previous studies have pointed out a good antimicrobial activity of two oxacillin salts--DBED--oxacillin and calcic oxacillin--which were conditioned as "preconditioned powders" for oral suspensions. The above mentioned preparations were followed up by administration to animals, and similar seric concentrations in DBED oxacillin and sodic oxacillin (with the difference that insoluble salts present a long-time activity) were pointed out.