Sergio Cafaggi

Development and Characterization of a Buccoadhesive Dosage Form of Oxycodone Hydrochloride

AbstractA buccoadhesive system for the delivery of oxycodone hydrochloride to the oral mucosa was prepared from a colloidal solution of gelatin used as a bioadhesive agent. An in vitro method for measuring the adhesion of release system to a substrate was developed by employing a modified balance. The eflects of thickness and of the presence of the drug on swelling and mucoadhesion properties were evaluated. The in vitro release of the buccoadhesive formulation was studied by a USP paddle dissolution apparatus and the results were fitted to an empirical equation. In vivo compliance and permanence time in 10 healthy volunteers were estimated.

Reduction of cisplatin hepatotoxicity by procainamide hydrochloride in rats

In preceding papers, we proposed that procainamide hydrochloride, a class I antiarrhythmic agent, was able to protect mice and rats from cisplatin-induced nephrotoxicity and that it could exert its action through accumulation in kidneys followed by coordination with cisplatin (or its hydrolysis metabolites) and formation of a less toxic platinum compound similar to the new platinum(II) triamine complex cis-diamminechloro-[2-(diethylamino)ethyl 4-amino-benzoate, N4]-chlorideplatinum(II) monohydrochloride monohydrate, obtained by the reaction of cisplatin with procaine hydrochloride. Hepatotoxicity is not considered as a dose-limiting toxicity for cisplatin, but liver toxicity can occur when the antineoplastic drug is administered at high doses. Here, we report that procainamide hydrochloride, at an i.p. dose of 100 mg/kg, reduces cisplatin-induced hepatotoxicity, as evidenced by the normalization of plasma activity of glutamic oxalacetic transaminase and gamma-glutamyl transpeptidase, as well as by histological examination of the liver tissue. Twenty-four hours after i.p. treatment with the combination of 7.5 mg/kg cisplatin and 100 mg/kg procainamide, a significant increase of procainamide (+56%, P<0.05), total platinum (+31%, P<0.05), platinum-DNA adducts (+31%, P<0.05) and percent DNA-DNA interstrand cross-links (+69%, P<0.02) was found in liver tissue, as compared to animals treated with cisplatin alone. Moreover, in accordance with these findings, we also observed a slightly lower concentration and cumulative excretion of platinum in the feces. Since mitochondrial injury is considered a central event in the early stages of the nephrotoxic effect of cisplatin, the distribution of platinum in these subcellular organelles obtained from hepatocytes was determined after treatment with cisplatin with or without procainamide hydrochloride, together with platinum concentration in their cytosolic fraction. Our data show that the coadministration of procainamide hydrochloride produced a rearrangement of subcellular platinum distribution in hepatocytes with a slight decrease in mitochondria (-15%, P<0.10) and a slight increase in the cytosolic fraction (+40%, P<0.10) of platinum content, compared to the treatment with cisplatin alone. In analogy with our previous results in the kidney, confirmed here by our data in vitro, we suggest that the hepatoprotective activity of procainamide hydrochloride is linked to the formation of a less toxic platinum complex, which leads to inactivation of cisplatin itself and/or its highly toxic hydrolysis metabolites and to a different subcellular distribution of platinum.

An example of application of a mixture design with constraints to a pharmaceutical formulation

The aim of this tutorial is to show the application of a mixture experimental design to a problem of pharmaceutical formulation. A gel, based on poloxamer 407, useful for topical administration of tolfenamic acid, a potent anti-inflammatory drug very poorly soluble in water, has been prepared, and a mixture experimental design was used to study the influence of the components on the viscosity of the formulation. Its application allowed to identify a critical boundary, separating semisolid formulations from liquid ones, within a narrow interval of concentrations of the components, and to estimate their effects on the viscosity of the preparation.

Development and In Vitro Evaluation of Buccoadhesive Tablets Using a New Model Substrate for Bioadhesion Measures: The Eggshell Membrane

For oral delivery of antimicrobial and anti-inflammatory drug, mucoadhesive tablets based on gelatin/hydroxypropylcellulose (HPC), gelatin/hydroxypropylmethyl-cellulose (HPMC), and gelatin/sodium carboxymethylcellulose (NaCMC) at different ratios were prepared by direct compression of the mixed powders. Metronidazole and benzydamine were used as model drugs. The in vitro bioadhesive properties, evaluated by a commercial tensile tester, were significantly affected by the model substrate employed, that is, a polypropylene (PP) membrane or a biological membrane (eggshell membrane). The use of the biological substrate seemed to supply more reliable data. All studied formulations showed an erosion-diffusion mechanism of release, anomalous or non-Fickian release, in agreement with the behavior of the swellable systems.

Antimicrobial Activity of the Ornamental Species Salvia corrugata, a Potential New Crop for Extractive Purposes

As a part of our search for biologically active compounds from cultivated Salvia spp. we investigated Salvia corrugata Vahl. The activity of two isolated icetaxane diterpene quinones, fruticuline A and demethylfruticuline A, was assessed against 46 bacterial pathogens, mostly resistant to several primary antibiotics. The MIC for all the inhibited Gram-positive pathogens tested showed a very narrow distribution and ranged from 32 to 64 mg/L, regardless of their resistance patterns to other antibiotics. Demethylfruticuline A was shown to be highly bactericidal (>3 log(10) CFU decrease within 24 h) against Staphylococcus aureus and S. epidermidis and bacteriostatic against Enterococcus faecalis and E. faecium. Fruticuline A manifested bacteriostatic activity against all tested strains. S. corrugata can be viewed as an interesting source for these diterpenes, which, if well tolerated in vivo, may represent new medical agents useful for the treatment of serious infections caused by resistant Gram-positive pathogens.

Phytotoxic clerodane diterpenes from Salvia miniata Fernald (Lamiaceae).

Our ongoing research to identify natural growth inhibitors with diterpene and triterpene skeletons exuding from the surface of the aerial parts of Salvia species led us to study Salvia miniata Fernald. Ten clerodane diterpenoids were found, along with three known diterpenes. Most of the isolated compounds from S. miniata inhibited the germination of Papaver rhoeas L. and Avena sativa L. in Petri dish experiments. Parallel results have been obtained in experiments carried out to evaluate the subsequent growth of the seedlings of the target species in the presence of the tested compounds.

Cytotoxicity and cellular accumulation of a new cis-diammineplatinum (II) complex containing procaine in murine L1210 cells sensitive and resistant to cis-diamminedichloroplatinum (II)

The emergence of drug resistance during tumor chemotherapy is one of the main problems associated with cancer treatment, particularly with cisplatin (cis-DDP). In the hope of overcoming this problem, various cis-DDP-derived compounds have been synthesized, and their pharmacological activity was compared with that of cis-DDP. In this paper we report on studies on the cytotoxic activity induced by cis-dia-mminechloro-[2-(diethylamino)ethyl-4-aminobenzoate, N4]-chlorideplatinum(II) monohydrochloride monohydrate (DPR), a new complex of platinum containing procaine. All experiments were carried out on murine leukemic cells, which were either sensitive (L1210) or resistant (L1210/DDP) to cis-DDP. A tetrazolium dye (MTT) assay conducted 5 days after a 2-h exposure of cells to both drugs was utilized to determine the resistance factor (RF) of L1210/DDP cells as compared with the sensitive wild-type cells. Drug accumulation and efflux, together with the amount of platinum bound to DNA, were also investigated. The activity of DPR on sensitive cells was not significantly different from that of cis-DDP. Conversely, DPR was 4.3 times more effective than cis-DDP on resistant cells. A decreased drug accumulation is one of the mechanisms of resistance to cis-DDP of L1210/DDP cells. However, DPR accumulation was not significantly different in sensitive and resistant L1210 cells. Under culture conditions that yielded similar intracellular platinum concentrations, treatment with DPR. produced significantly greater DNA platination than did treatment with cis-DDP in both cell lines. No difference in efflux was observed between L1210 and L1210/DDP cells exposed to either cis-DDP or DPR. Our results show that in parental cells, DPR is as potent as cis-DDP on a molar basis, and it is also minimally cross-resistant with cis-DDP in L1210/DDP cells. A direct implication of our results is that DPR could be useful in those human tumors showing a mechanism of resistance similar to that of L1210/ DDP cells.

Stability indicating HPLC assay for retinoic acid in hard gelatine capsules containing lactose and as bulk drug substance

A reversed phase high performance liquid chromatographic assay for determination of Retinoic Acid in raw materials and in hard gelatine capsules containing Tablettose® as excipient is described. The method uses a UV diode array detector. The solution concentrations were measured on weight basis to avoid the use of an internal standard, otherwise necessary for the presence of the undissolved matrix. The study of the recoveries, planned in a Latin square as experimental design, shows that the accuracy and precision of the method are excellent. The assay is selective and stability indicating. The method resolves three related substances (13-cisretinoic acid, 5,6-epoxy-5,6-dihydroretinoic acid and 4-oxo-retinoic acid) with quantitation in the range 0.04 % 0.2 % of the labelled amount of Retinoic Acid (10 mg).

Inhibition of Cell Growth, Induction of Apoptosis and Mechanism of Action of the Novel Platinum Compound cis-Diaminechloro-[2-(Diethylamino) Ethyl 4-Amino-Benzoate, N4]-Chloride Platinum (II) Monohydrochloride Monohydrate

Cis-diaminechloro-[2-(diethylamino) ethyl 4-amino-benzoate, N4]-chloride platinum (II) monohydrochloride monohydrate (DPR) is a new platinum triamine complex obtained from the synthesis of cisplatin and procaine. In this paper we analyzed, adopting a disease-oriented strategy, the tumour selectivity of this compound, its ability to induce apoptosis and its mechanism of interaction with DNA. The inhibition of cell proliferation was evaluated by the MTT assay using a panel of 51 tumour cell lines. Some of them were also evaluated for the induction of apoptosis by 4′-6-diamidine-2′-phenylindole (DAPI) staining, Western blot of p53 protein and agarose gel electrophoresis of ladder DNA. Finally, interstand cross-links (ISCL) were evaluated by ethidium bromide fluorescence technique.When evaluated by the MTT assay, DPR showed a high selective activity for neuroblastoma, small cell lung cancer (SCLC), ovarian cancer and leukemia cell lines. The comparison of mean graphs of DPR and cisplatin suggested that our compound possesses a mechanism of action similar to that, at least in part, of its parent compound. Moreover, DPR showed itself to be a good trigger of programmed cell death, as demonstrated by DAPI staining, activation of p53 protein and agarose gel electrophoresis of ladder DNA. Finally, the study of the formation of ISCLs demonstrated that DPR, despite being a monofunctional platinum compound, is able to form bifunctional adducts through the release of procaine residue.Data presented here suggest that DPR is an antitumour agent able to trigger apoptosis, and that it is endowed with a peculiar mechanism(s) of action and a special selective activity against two tumours, namely neuroblastoma and SCLC, which are still characterized by a low incidence of long-term survivors.

Combination of cisplatin-procaine complex DPR with anticancer drugs increases cytotoxicity against ovarian cancer cell lines.

DPR, cis-diamminechloro-[2-(diethylamino)ethyl 4-amino-benzoate, N4]-chlorideplatinum(II) monohydrochloride monohydrate, is a newly developed water-soluble platinum compound which possess minimal cross-resistance to cisplatin and shows relatively less side effects. In an attempt to establish whether the combination of DPR with other conventional anticancer drugs would be of any benefit we assessed in vitro the cytotoxic effects of combinations of DPR with the antimetabolites 5-fluorouracil (5-FU) and methotrexate (MTX), the alkylating agents mitomycin C (MMC) and cisplatin, the antimicrotubule agent taxol (TAX), and the intercalating agent of the anthracycline group doxorubicin (DOX) on murine M5076 ovarian reticulosarcoma and human A2780 ovarian carcinoma cells. These agents were selected because of their common use in the clinic and because they represent four distinct categories of antineoplastic mechanisms. Cells were incubated for 72 h in the presence of single or combined drugs, and the cytotoxic effect was determined by the MTT assay. The analysis of combination treatment was made by the isobole method. In human A2780 cells, an overall synergy was found for DPR combined with 5-FU, DOX and cisplatin. Synergistic effects were also observed for most combinations with MTX or MMC. A DPR concentration-dependent additivity and antagonism was seen at the highest MTX concentration (1 microM), while additive effects were observed for the combined treatments of DPR and low concentrations of MMC (0.008 and 0.0016 microM). Additive effects were also observed for the association of DPR and TAX over most combinations tested. In murine M5076 cells, synergism was the prevailing result observed when DPR was combined with 5-FU, DOX, MMC or cisplatin. When administered together with MTX we observed additivity over most combinations tested. These findings suggest that DPR, when simultaneously administered with standard anticancer agents, may be advantagious for cytokilling.