Polyvinylpyrrolidone microneedles for localized delivery of sinomenine hydrochloride: preparation, release behavior of in vitro & in vivo, and penetration mechanism

Sinomenine (SIN) is an anti-inflammatory alkaloid derived from Sinomenium acutum, and the products sinomenine hydrochloride (SH) tablets and injections have been marketed in China to treat rheumatoid arthritis (RA). Oral administration of SH has shortcomings of gastrointestinal irritation and low bioavailability. The injection may require professional training and higher cost. It is of interest to develop an alternative form that is easier to administer and avoids the first-pass metabolism. In this study, SH-loaded dissolving microneedles (SH-MN) were fabricated using polyvinyl pyrrolidone and chondroitin sulfate with a casting method. In percutaneous permeation studies of In vitro, the cumulative permeation and permeation rate of SH-MN were 5.31 and 5.06 times higher than that of SH-gel (SH-G). In percutaneous pharmacokinetic studies, the values of the area under the curve after administration of SH-MN in the skin and blood were 1.43- and 1.63-fold higher than that of SH-G, respectively. In percutaneous absorption studies, SH-MN could absorb into tissue fluid; and dissolve after skin penetration. The drug was released along the channel and spread to surrounding skin tissue. After 4 h, the needle tip was almost completely dissolved, and the drug could penetrate to a depth of 200 μm under the skin. These results demonstrate that the SH-MN is an effective, safe, and simple strategy for transdermal SH delivery.

Carbon dot cross-linked polyvinylpyrrolidone hybrid hydrogel for simultaneous dye adsorption, photodegradation and bacterial elimination from waste water

The creation of a polymeric hydrogel from polyvinylpyrrolidone (PVP) cross-linked by Carbon Quantum Dots (CD) for the adsorption and photocatalytic degradation of both cationic and anionic dyes. PVP, an important biocompatible constituent and often surplus in cosmetic industry, was carboxylated through NaOH refluxing and covalently conjugated to surface amine functionality of CD derived from lemon juice and Cysteamine. The hybrid hydrogel was obtained from PVP-CD covalent conjugate by careful manipulation of pH and found to possess better rheological properties than only carboxylate-PVP. The monolayer physisorption of the dyes on the hydrogel was affected by hydrogen bonding, dispersion or inductive effect, and π-π interaction with the polymer backbone as well as the CD that followed pseudo-second-order kinetics. Degradation of the adsorbed dyes was instated by the unique Reactive Oxygen Species (ROS) generating ability of the CD embedded in the hydrogel matrix upon exposure to sunlight, the mechanism of which is also unveiled. The same CD-induced ROS was found to effectively annihilate both gram-positive and gram-negative bacteria in real polluted water in less than 10 min of photoexcitation of the hydrogel. The hydrogel was restored by mild acid wash that is able to perform dye adsorption and photo-degradation upto four cycles.

Evaluating supersaturation in vitro and predicting its performance in vivo with Biphasic gastrointestinal Simulator: A case study of a BCS IIB drug

This study aimed to develop an evaluation approach for supersaturation by employing an in vitro bio-mimicking apparatus designed to predict in vivo performance. The Biphasic Gastrointestinal Simulator (BGIS) is composed of three chambers with absorption phases that represent the stomach, duodenum, and jejunum, respectively. The concentration of apatinib in each chamber was detected by fiber optical probes in situ. The dissolution data and the pharmacokinetic data were correlated by Gastroplus^TM. The precipitates were characterized by polarizing microscope, Scanning Electron Microscopy, Powder X-ray diffraction and Differential scanning calorimetry. According to the results, Vinylpyrrolidone-vinyl acetate copolymer (CoPVP) prolonged supersaturation by improving solubility and inhibiting crystallization, while Hydroxypropyl methylcellulose (HPMC) prolonged supersaturation by inhibiting crystallization alone. Furthermore, a predictive in vitro-in vivo correlation was established, which confirmed the anti-precipitation effect of CoPVP and HPMC on in vitro performance and in vivo behavior. In conclusion, CoPVP and HPMC increased and prolonged the supersaturation of apatinib, and then improved its bioavailability. Moreover, BGIS was demonstrated to be a significant approach for simulating in vivo conditions for in vitro-in vivo correlation in a supersaturation study. This study presents a promising approach for evaluating supersaturation, screening precipitation inhibitors in vitro, and predicting their performances in vivo.

Translocation, biotransformation-related degradation, and toxicity assessment of polyvinylpyrrolidone-modified 2H-phase nano-MoS2

Nano-MoS2 has been extensively investigated in materials science and biomedicine. However, the effects of different methods of exposure on their translocation, biosafety, and biotransformation-related degradability remain unclear. In this study, we combined the advantages of synchrotron radiation (SR) X-ray absorption near-edge structure (XANES) and high-resolution single-cell SR transmission X-ray microscopy (SR-TXM) with traditional analytical techniques to investigate translocation, precise degraded species/ratio, and correlation between the degradation and toxicity levels of polyvinylpyrrolidone-modified 2H-phase MoS2 nanosheets (MoS2-PVP NSs). These NSs demonstrated different biodegradability levels in biomicroenvironments with H2O2, catalase, and human myeloperoxidase (hMPO) (H2O2 < catalase < hMPO). The effects of NSs and their biodegraded byproducts on cell viability and 3D translocation at the single-cell level were also assessed. Toxicity and translocation in mice via intravenous (i.v.), intraperitoneal (i.p.), and intragastric (i.g.) administration routes guided by fluorescence (FL) imaging were investigated within the tested dosage. After i.g. administration, NSs accumulated in the gastrointestinal organs and were excreted from feces within 48 h. After i.v. injection, NSs showed noticeable clearance due to their decreased accumulation in the liver and spleen within 30 days when compared with that in the i.p. group, which exhibited slight accumulation in the spleen. This work paves the way for understanding the biological behaviors of nano-MoS2 using SR techniques that provide more opportunities for future applications.

An In vivo study: Adjuvant activity of poly-n-vinyl-2-pyrrolidone-co-acrylic acid on immune responses against Melanoma synthetic peptide

Peptides have been studied as an important class of components in medicine to control many major diseases with vaccination. Polymers as adjuvants are capable of enhancing the vaccine potential against various diseases by improving the delivery of antigens, and they reduce the booster doses of vaccines. In brief, polymers are promising candidates for peptide-based vaccine delivery platforms. The purpose of the present study was to create a possible alternative approach in the treatment of malignant melanoma and/or to prevent metastasis of melanoma. The study was designed as both an experimental and an in vivo study. We prepared a complex and covalent conjugate of MAGE-3 121-134 (L-L-K-Y-R-A-R-E-P-V-T-K-A-E) T-cell epitope as a vaccine candidate for melanoma. These conjugates were able to generate an immune response in mice after a single immunization, without the help of any external adjuvant. The peptide-polymer complexes activated the immune system in the best way and formed the highest antigen specific immune response. These results indicate the adjuvant activity of Poly(N-vinyl-2- pyrrolidone-co-acrylic acid) [P(VP-co-AA)] and the potential use of P(VP-coAA)-peptide based vaccine prototypes for future melanoma cancer vaccine formulations.

Nose-to-brain delivery of insulin enhanced by a nanogel carrier

Recent evidences suggest that insulin delivery to the brain can be an important pharmacological therapy for some neurodegenerative pathologies, including Alzheimer disease (AD). Due to the presence of the Blood Brain Barrier, a suitable carrier and an appropriate route of administration are required to increase the efficacy and safety of the treatment. Here, poly(N-vinyl pyrrolidone)-based nanogels (NG), synthetized by e-beam irradiation, alone and with covalently attached insulin (NG-In) were characterized for biocompatibility and brain delivery features in a mouse model. Preliminarily, the biodistribution of the "empty" nanocarrier after intraperitoneal (i.p.) injection was investigated by using a fluorescent-labeled NG. By fluorescence spectroscopy, SEM and dynamic light scattering analyses we established that urine clearance occurs in 24h. Histological liver and kidneys inspections indicated that no morphological alterations of tissues occurred and no immunological response was activated after NG injection. Furthermore, after administration of the insulin-conjugated nanogels (NG-In) through the intranasal route (i.n.) no alteration or immunogenic response of the nasal mucosa was observed, suggesting that the formulation is well tolerated in mouse. Moreover, an enhancement of NG-In delivery to the different brain areas and of its biological activity, measured as Akt activation levels, with reference to free insulin administration was demonstrated. Taken together, these results indicate that the synthesized NG-In enhances brain insulin delivery upon i.n. administration and strongly encourage its further evaluation as therapeutic agent against some neurodegenerative diseases.

Rapidly dissolving polymeric microneedles for minimally invasive intraocular drug delivery

In this study, dissolving microneedles (MNs) were used to enhance ocular drug delivery of macromolecules. MNs were fabricated using polyvinylpyrrolidone (PVP) polymer of various molecular weights (MWs) containing three model molecules of increasing MW, namely fluorescein sodium and fluorescein isothiocyanate-dextrans (with MW of 70 k and 150 k Da). Arrays (3 × 3) of PVP MNs with conical shape measuring about 800 μm in height with a 300 μm base diameter, containing the model drugs, were fabricated and characterized for their fracture forces, insertion forces (in the sclera and cornea), depth of penetration (using OCT and confocal imaging), dissolution time and in vitro permeation. The average drug content of the MNs (only in MN shafts) ranged from 0.96 to 9.91 μg, and the average moisture content was below 11 %. High MW PVP produced MNs that can withstand higher forces with minimal reduction in needle height. PVP MNs showed rapid dissolution that ranged from 10 to 180 s, which was dependent upon PVP's MW. In vitro studies showed significant enhancement of macromolecule permeation when MNs were used, across both the corneal and scleral tissues, in comparison to topically applied aqueous solutions. Confocal images showed that the macromolecules formed depots within the tissues, which led to sustained permeation. However, use of MNs did not significantly benefit the permeation of small molecules; nevertheless, MN application has the potential for drug retention within the selected ocular tissues unlike topical application for small molecules. The material used in the fabrication of the MNs was found to be biocompatible with retinal cells (i.e. ARPE-19). Overall, this study reported the design and fabrication of minimally invasive rapidly dissolving polymeric MN arrays which were able to deliver high MW molecules to the eye via the intrastromal or intrascleral route. Thus, dissolving MNs have potential applications in enhancing ocular delivery of both small and macromolecules.

Dual-Enzyme Characteristics of Polyvinylpyrrolidone-Capped Iridium Nanoparticles and Their Cellular Protective Effect against H2O2-Induced Oxidative Damage

Polyvinylpyrrolidone-stabilized iridium nanoparticles (PVP-IrNPs), synthesized by the facile alcoholic reduction method using abundantly available PVP as protecting agents, were first reported as enzyme mimics showing intrinsic catalase- and peroxidase-like activities. The preparation procedure was much easier and more importantly, kinetic studies found that the catalytic activity of PVP-IrNPs was comparable to previously reported platinum nanoparticles. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) characterization indicated that PVP-IrNPs had the average size of approximately 1.5 nm and mainly consisted of Ir(0) chemical state. The mechanism of PVP-IrNPs' dual-enzyme activities was investigated using XPS, Electron spin resonance (ESR) and cytochrome C-based electron transfer methods. The catalase-like activity was related to the formation of oxidized species Ir(0)@IrO2 upon reaction with H2O2. The peroxidase-like activity originated from their ability acting as electron transfer mediators during the catalysis cycle, without the production of hydroxyl radicals. Interestingly, the protective effect of PVP-IrNPs against H2O2-induced cellular oxidative damage was investigated in an A549 lung cancer cell model and PVP-IrNPs displayed excellent biocompatibility and antioxidant activity. Upon pretreatment of cells with PVP-IrNPs, the intracellular reactive oxygen species (ROS) level in response to H2O2 was decreased and the cell viability increased. This work will facilitate studies on the mechanism and biomedical application of nanomaterials-based enzyme mimic.

Comparison and potential of hypo-osmotic and iso-osmotic erythrocyte ghosts and carrier erythrocytes as drug and enzyme carriers

Preparation, characteristics and properties of the three types of erythrocyte ghost are compared. These include light scattering properties, morphology, retention of cellular components and biochemical function including membrane transport. In vivo studies in the BALB/c mouse and Beagle dog have allowed the potential to be assessed of these erythrocyte ghosts as drug and enzyme cellular carriers in the treatment of human diseases. The development of the carrier erythrocyte with restored cellular ATP content and properties, including in vivo survival, that are closely similar to those of the normal erythrocyte is also described and its potential discussed.

[The role of surrogate alcoholic beverages in the development of hemorrhage in the patients presenting with Mallory-Weiss syndrome]

The objective of the present work was to study the pathological changes in various organs and tanatogenesis associated with Mallory-Weiss syndrome making use of the forensic medical and clinical materials. It was shown that the main cause of unrestrained vomiting resulting from alcoholic intoxication and leading to perfusive bleeding is not only the direct action of ethanol and surrogate alcohol on gastroesophageal mucosa and induced thrombocytopenia. Another cause may be brain oedema with subsequent cerebral herniation and irritation of the pseudobulbar centres responsible for the initiation of the vomiting reflex. The authors propose recommendations for forensic medical diagnostics of the cases of such hemorrhage.

[Preparation and pharmacokinetics of brucine hydrogel patch]

OBJECTIVE

To investigate the effect of dose on pharmacokinetic properties of brucine hydrogel patch.

METHODS

The plasma concentration of brucine was determined by HPLC. Brucine hydrogel patch was prepared and its pharmaceutical characterization was investigated. After transdermal administration of different dose brucine hydrogel patch; Plasma concentration versus time profiles were determined and pharmacokinetic parameters were calculated by DAS program.

RESULTS

The pharmaceutical properties of brucine hydrogel patch were satisfactory. The AUC0-1 values were 7.24 +/- 0.61, 16.02 +/- 2.34 and 54.84 +/- 26.59 microg x h/mL after administration of 30, 60 and 180 mg/kg brucine hydrogel patch, respectively. The corresponding C(max) values were 0.73 +/- 0.23, 1.45 +/- 0.28 and 4.59 +/- 1.85 microg/mL, respectively. And the corresponding T(max) values were 8.67 +/- 2.07, 11.67 +/- 2.66 and 8.33 +/- 2.65 h, respectively.

CONCLUSION

The pharmacokinetic properties of brucine do not vary with the dose of brucine hydrogel patch.

[Preparation of ibuprofen/EC-PVP sustained-release composite particles by supercritical CO2 anti-solvent technology]

Ibuprofen/ethyl-cellulose (EC)-polyvinylpyrrolidone (PVP) sustained-release composite particles were prepared by using supercritical CO2 anti-solvent technology. With drug loading as the main evaluation index, orthogonal experimental design was used to optimize the preparation process of EC-PVP/ibuprofen composite particles. The experiments such as encapsulation efficiency, particle size distribution, electron microscope analysis, infrared spectrum (IR), differential scanning calorimetry (DSC) and in vitro dissolution were used to analyze the optimal process combination. The orthogonal experimental optimization process conditions were set as follows: crystallization temperature 40 degrees C, crystallization pressure 12 MPa, PVP concentration 4 mgmL(-1), and CO2 velocity 3.5 Lmin(-1). Under the optimal conditions, the drug loading and encapsulation efficiency of ibuprofen/EC-PVP composite particles were 12.14% and 52.21%, and the average particle size of the particles was 27.621 microm. IR and DSC analysis showed that PVP might complex with EC. The experiments of in vitro dissolution showed that ibuprofen/EC-PVP composite particles had good sustained-release effect. Experiment results showed that, ibuprofen/EC-PVP sustained-release composite particles can be prepared by supercritical CO2 anti-solvent technology.

[Optimization of the matrix formulation of compound Die Da Zhen Tong cataplasm by uniform design]

OBJECTIVE

To optimize the matrix formulation of compound Die Da Zhen Tong cataplasm.

METHODS

The optimal preparation was selected by U17 (17(16)) uniform design, independent variables were the percentage ratio of the matrix formulation component part in compound Die Da Zhen Tong cataplasm,and the viscosity, continued viscosity and overall desirability used as indexes were dependent variables.

RESULTS

The percentage of the matrix formulation component part in compound Die Da Zhen Tong cataplasm was, NP-700: carbomer 980: PVP K-90: dihydroxy aluminum: tartaric: kaolinite: sorbitol: glycerin = 5: 1. 2: 2.5: 0.25: 0.15:4: 12: 5.

CONCLUSION

The optimized cataplasm has good viscosity, continued viscosity and high overall desirability.

[Collagen-polyvinylpyrrolidone: a new therapeutic option for treatment of sequelae after radical mastectomy in women with breast cancer. Preliminary study]

BACKGROUND

Approximately 30% of women who undergo mastectomy without reconstructive treatment due to breast cancer present sequelae. These include paresthesias, keloid healing, hypoesthesia, lymphedema and limitation of the function of the ipsilateral upper extremity. We undertook this study to present the results using collagen-polyvinylpyrrolidone (Clg- Pvp) as treatment for posmastectomy sequelae in women with breast cancer.

METHODS

We conducted a unicentric, longitudinal and prospective clinical trial between August 1, 2007 and July 31, 2008. Included variables were age, lymphedema, limitation of the function of the ipsilateral upper extremity, collapse of the wound, keloid healing, paresthesias, and appearance of the surgical area. The appearance of the surgical area (aesthetic aspect) was evaluated before and 6 months after treatment was initiated. Clg-Pvp was administered weekly for a 6-month period.

RESULTS

Seven women were included with a median age of 49 years (range: 40-72 years). One patient (14.28%) presented lymphedema, two patients (28.57%) presented collapse of the wound, two patients (28.57%) had keloid healing, three patients (42.85%) experienced paresthesias, five patients (71.4%) reported pain, and five patients (71.4%) reported limitation of the function of the ipsilateral upper extremity. At the completion of the treatment, aesthetic improvement was statistically significant (p = 0.0020, Mann-Whitney U test).

CONCLUSIONS

Clinical and aesthetic results are good after application of Clg-Pvp for treating sequelae in women with breast cancer who underwent mastectomy without reconstructive surgery.

Evaluation of a mucoadhesive lipid-based bioerodable tablet compared with Biotène mouthwash for dry mouth relief--a pilot study

OBJECTIVE

Salivary gland impairment is a major problem that can result in hyposalivation and a decrease in quality of life. Causes for mouth dryness can be grossly classified into three major groups: iatrogenic, immunogenic, and metabolic. At present, insufficient therapies exist to ease morbidity in this growing number of affected individuals. A need for new products to relieve oral dryness is mandatory. The aim of this study was to evaluate a mucoadhesive lipid-based bioerodable tablet as a novel device to decrease signs and symptoms associated with mouth dryness.

METHOD AND MATERIALS

Twenty xerostomic patients were divided into two groups. In group 1, the mucoadhesive tablet was applied to the hard palate, while in group 2, Biotène mouthwash was applied and served as a control. Sialometry measurements, as well as a questionnaire assessing mouth dryness, were obtained before and after treatment.

RESULTS

Application of the mucoadhesive tablets resulted in a significant reduction in the sensation of the mouth dryness (P = .016) compared to Biotène. Moreover, a 1.5-fold increase in unstimulated whole saliva flow was obtained after 30 minutes in the treatment group.

CONCLUSION

A lipid-based mucoadhesive tablet has a beneficial role in reducing the sensation of dryness in patients with xerostomia.

[Further improvement of the methods for the arrest of nasal bleeding]

Gauze tamponade of the nasal cavity is one of the most popular and convenient methods for the arrest of nasal bleeding. We used a polyvinyl pyrrolidone (PVP) powder that prevents local fibrinolysis by virtue of its sorption properties. PVP placed on the tampons and insufflated into the nasal cavity after their removal was shown to significantly decrease manifestations of reactive oedema and frequency of recurrent bleeding. These effects are attributable to the modifying action of PVP on fibrin thrombus and amplification of erythrocyte aggregation. On the one hand, fibrin thrombi formed close to the source of bleeding become harder due to the thickening of fibrin filaments; on the other hand, increased permeability of the fibrin network facilitates unobstructed penetration of fibrinolytic factors into the nasal cavity where they are sorbed and inactivated by PVP molecules. The hemostatic effect of PVP is promoted by enhanced erythrocyte aggregation.

Clinical evaluation of De Marco formula as an adjunctive therapy for infected ischemic diabetic foot: a prospective randomized controlled trial

BACKGROUND

De Marco Formula (DMF) is a novel formulation of procaine and PVP.

OBJECTIVE

To assess the efficacy and safety of DMF as an adjunctive therapy for infected ischemic diabetic foot in a prospective randomized controlled clinical trial.

METHODS

Adult patients, 39 male/ 79 female, were randomly assigned (59 patients/treatment group) to the conventional therapy alone (A) or plus DMF (0, 15 ml/kg .day i.m.) during ten days and them twice a week until healing of the lesions or completion of 52 days (B).The response to the treatment was considered favorable when an amputation was not needed even though a decrease of the wound area or complete healing was not shown. It was considered unfavorable when a major amputation was necessary because of worsening of the lesion (wound spreading to any magnitude greater than the initial one) or the appearance of new wounds in the same leg.

RESULTS

Both groups were comparable with regard to age, sex, level of arterial occlusion, type of lesion, anatomic localization of lesions and previous surgical procedures. The cumulative percentage of unfavorable results was significantly lower after treatment B with respect to treatment A (25.4% vs. 45.8%; p= 0.02), for a reduction of 44.5%. Four slight adverse reactions were associated with DMF: vertigo and nausea at the 7th treatment administration (one patient), and headache and tachycardia at the 12th dose (another patient). Blood hemoglobin and leukocyte counts and serum alanine transaminase were not affected.

CONCLUSION

The treatment with DMF for 52 days as an adjuvant for the conventional therapy was associated with a lower need for major amputations. It was also well tolerated and safe.

Storage of polyvinylpyrrolidone (PVP) in tissues following long-term treatment with a PVP-containing vasopressin preparation

The parenteral use of polyvinylpyrrolidone (PVP) leads to PVP retention in the human organism. Four case histories dealing with patients on long-term treatment with a PVP-containing vasopressin preparation are presented and the possibility of a harmful effect of the PVP storage is discussed. The presence of PVP in serum, demonstrated by lipoprotein electrophoresis, is described. Based on the literature and the present findings, a withdrawal of PVP-containing preparations for injectional purposes is advocated.

[Preparation of Zhongjiefeng dispersible tablets]

OBJECTIVE

To prepare Zhongjiefeng dispersible tablets.

METHODS

The formulation of Zhongjiefeng dispersible tablets were optimized as index of disintegration time by orthogonal design test.

RESULTS

The optimized Zhongjiefeng dispersible tablets, which were prepared by selecting 16% PVPP and 3% L-HPC as disintegrants, 40% MCC as filler, can disintegrate in 3 mins.

CONCLUSIONS

The above formulation is reasonable and the disintegration time is suitable, so it can provide theoretic support for industrialization.

A Novel Formulation for Mebeverine Hydrochloride

The antispasmodic drug mebeverine hydrochloride was formulated into a film-forming gel to be used as a topical local anesthetic. A mixture of cellulose derivatives was used as a base. Additives were used to enhance the release as well as the residence time. Formulations were characterized in terms of drug release, mucoadhesion and rheology. Clinically, the selected formula has shown faster onset (p = 0.0156), longer duration (p = 0.0313), better film residence (p = 0.0313), and no foreign body sensation (p = 0.0313) in comparison to Solcoseryl dental paste. Histopathological examination showed no change in inflammatory cells count, concluding that this topical anesthetic is efficacious and safe orally.

[Local therapy of grade IIa burns: efficacy and tolerability of a new hydrosome wound gel for the local treatment of grade IIa burns as compared with silver sulfadiazine ointment]

BACKGROUND

A new hydrosome wound gel is based on a new mechanism of action. It contains hydrosomes that penetrate to the wound bed and supply the wound with phospholipids, which are identical to membrane phospholipids of human cells. In this manner it supports the proliferative processes during wound healing.

PATIENTS AND METHODS

In a randomized, controlled, intraindividual comparative study of 47 patients with grade IIa burns, the hydrosome wound gel was tested against silver sulfadiazine cream. Digital pictures of the burn wounds were taken daily, and the wounds were analyzed in terms of their reepithelization rate.

RESULTS

Wounds receiving the hydrosome wound gel healed 1.5-2 days faster than wounds treated with sulfadiazine cream (9.9+/-4.5 days vs. 11.3+/-4.9 days, p=0.015). In 66% of the patients, faster epithelization was observed with the hydrosome wound gel treatment. The hydrosome gel guaranteed secure prophylaxis against infection, and it was well tolerated and easy to apply.

CONCLUSION

In this study, the treatment of grade IIa burn wounds with hydrosome wound gel led to faster wound closure compared with treatment with sulfadiazine cream. Therefore, hydrosome gel represents a good alternative to sulfadiazine cream.

Ileocolonic ulcer treated by endoscopic application of collagen-polyvinylpyrrolidone

Ulceration is a complication that may occur after an ileocolonic anastomosis. Most of the etiologies remain speculative. The case of a 33-year-old woman with eosinophilic colitis is reported, in whom a colectomy with an ileocolonic anastomosis was performed. After four months, the patient presented with a stenosis in the ileocolonic anastomosis, necessitating surgical restoration. Four weeks later, the patient presented with rectal bleeding, and a colonoscopy showed an ulcer in the anastomosis. Collagen-polyvinylpyrrolidone was applied into and on the surface of the ulcer, and five days later the procedure was repeated. Follow-up endoscopies at seven days and three months showed complete healing of the ulcer and the patient remained without bleeding throughout a further four weeks of follow-up tests. It was concluded that this biological product could be an excellent treatment for these lesions.

[Jumper's knee. Surgery and arthroscopic treatment with scraping and povidone collagen in high-performance athletes]

The jumper's knee or patellar tendonitis is a common injury in the athlete with an incidence between 14% and 16% among high-performance athletes. In addition to an overuse injury, there are some intrinsic factors for its development. Conservative treatment is indicated for the initial form, but when it fails, surgical treatment should be performed with an appropriate rehabilitation program.

MATERIAL AND METHODS

We retrospectively studied 18 high performance athletes in various disciplines, with an average age of 22 years, operated by arthroscopy and mini-arthrotomy scraping and application of povidone collagen sponge between March 2001 and December 2005. There after patients underwent a rehabilitation program specific for their return to their athletic activity.

RESULTS

The patients returned to their sports activity in an average of 15 weeks, with functional knees without pain, with full range of motion. We did not find postoperative fibrosis.

DISCUSSION

The results were similar and slightly better in time of return to sports activities to those reported in the world literature, with the difference in follow up. According to the clinical evaluation, treatment performed allows functional improvement with a return to athletic activity in a reasonable time.

Effect of hydrophilic polymers on buccoadhesive Eudragit patches of propranolol hydrochloride using factorial design

The purpose of this study was to develop formulations and systematically evaluate in vitro performances of buccoadhesive patches of propranolol hydrochloride using the hydrophobic polymer Eudragit L-100 as the base matrix. The hydrophilic polymers Carbopol 934 and polyvinyl pyrrolidone (PVP) K30 were incorporated into the Eudragit patches, to provide the patches with bioadhesive properties and to modify the rate of drug release. The patches, which were prepared by the solvent casting method, were smooth and elegant in appearance; were uniform in thickness, weight, and drug content; showed no visible cracks; and showed good folding endurance. A 3(2) full factorial design was employed to study the effect of independent variables like hydrophilic polymers Carbopol 934 and PVP K30, which significantly influenced characteristics like swelling index, ex vivo mucoadhesive strength, in vitro drug release, and ex vivo residence time. A stability study of optimized Eudragit patches was done in natural human saliva; it was found that both drug and buccal patches were stable in human saliva. It can be concluded that the present buccal formulation can be an ideal system to improve the bioavailability of the drug by avoiding hepatic first-pass metabolism.

Effect of Characteristics of Compounds on Maintenance of an Amorphous State in Solid Dispersion with Crospovidone

Solid dispersion (SD) of indomethacin with crospovidone (CrosPVP) shows useful characteristics for preparation of dosage forms. This study aimed to determine the types of drugs that could adopt a stable amorphous form in SD. Twenty compounds with various melting points (70-218 degrees C), molecular weights (135-504) and functional groups (amide, amino, carbonyl, hydroxyl, ketone etc.) were prepared in SD with CrosPVP. The CrosPVP SDs were prepared using a mechanical mixing and heating method. Melting point and molecular weight were found to have no influence on the ability of a compound to maintain an amorphous state in SD. All compounds containing hydrogen-bond-donor functional groups existed in an amorphous state in SD for at least 6 months. Infrared spectra suggested an interaction between the functional groups of these compounds and amide carbonyl group of CrosPVP. Compounds without hydrogen-bond-donor groups could not maintain an amorphous state and underwent recrystallization within 1 month. It was suggested that the presence of a hydrogen-bond-donor functional group in a compound is an important factor affecting the stable formation of SD with CrosPVP, which contains a hydrogen-bond acceptor.

Chlorin e6-polyvinylpyrrolidone as a fluorescent marker for fluorescence diagnosis of human bladder cancer implanted on the chick chorioallantoic membrane model

The use of fluorescence diagnosis as a modern cancer diagnostic modality is rapidly gaining importance in the field of urology. It is based on the detection of distinctive light emission of tissues sensitized by fluorescent dyes, commonly referred to as photosensitizers, after irradiation with a specific light source. Therefore, the search for specific fluorescent dyes with high sensitivity and specificity for bladder cancer is constantly being sought after. The aim of this study is to investigate the use of a new formulation consisting a mixture of chlorin e6 and polyvinylpyrrolidone (Ce6-PVP) for the detection of human bladder cancer cells (MGH) implanted on the chick chorioallantoic membrane (CAM) model. Uptake kinetics studies were quantitatively determined for both systemic and topical administrations of Ce6-PVP to the normal CAM as well as the MGH human bladder tumor implanted on CAM using fluorescence imaging technique. Rapid elimination of Ce6-PVP was displayed following topical application compared to systemic administration in the normal CAM system. Ce6-PVP was found to localize selectively in the xenografted bladder tumor in contrast to the CAM tissue. Neither dark toxicity nor irritancy was observed on the CAM tissue at the dose of 2 mg/kg Ce6-PVP. In conclusion, the Ce6-PVP formulation appeared to have the potential as a fluorescent marker for fluorescence diagnosis of human bladder cancer.

[The effect of oculotect gel on the conjunctival goblet cells of rat after corneal transplantation]

PURPOSE

To investigate the effect of oculotect gel and alteration of goblet cells of rat after corneal transplantation.

METHODS

48 SD rats were randomly divided into oculotect gel-treated, 0.1% dexamethasone eye drops-treated, control groups and normal groups. After the rat model of heterograft-heterotopic graft rejection was made, slit-limp microscope and PAS stainings, light microscope and HE PAS staining technique were used to observe the number and morphological difference of goblet cells in conjunctiva between operative groups and normal groups.

RESULTS

The HE PAS staining detection showed that the number of conjunctiva goblet cells in oculotect gel group 0.1% dexamethasone eye drops group and control groups is lower than that in normal group after surgery (P < 0.01). The number of conjunctiva goblet cells in oculotect gel group and 0.1% dexamethasone eye drops group is higher than that in control group (P < 0.05). That number in 0.1% dexamethasone eye drops group is higher than that in oculotect gel group (P < 0.05).

CONCLUSIONS

The results indicate that oculotect gel significantly inhibit the decrease of goblet cells after corneal allograft rejection in rats.

Photodynamic efficacy of topical application of chlorin e6--polyvinyl pyrrolidone complex in tumor-bearing rats

AIM

To evaluate the antitumor efficacy of photodynamic therapy with ointment form of chlorin e6--polyvinyl pyrrolidone complex.

METHODS

2 or 5% chlorin e6 ointment was applied on the surface of rat SM-1 tumor for 15 min-5 h, and then tumors were scored for photosensitizer accumulation and tissue damage induced by laser irradiation.

RESULTS

Selectivity of chlorin e6 accumulation in tumor tissues considerably increases when photosensitizer was applied topically compared with intravenous administration. Antitumor efficacy of photodynamic therapy using topical application of chlorin e6--polyvinyl pyrrolidone complex is just as high as upon intravenous administration of the preparation.

CONCLUSION

The level of tissue accumulation of chlorin e6--polyvinyl pyrrolidone complex administered in ointment form allows to carry out fluorescence diagnosis and PDT of superficially localized malignant tumors.

Molecular Interaction among Probucol/PVP/SDS Multicomponent System Investigated by Solid-State NMR

PURPOSE

Effects of polyvinylpyrrolidone (PVP) molecular weight on the solid-state intermolecular interactions among probucol/PVP/sodium dodecyl sulfate (SDS) ternary ground mixtures (GM) and the formation of nanoparticles were investigated by solid-state NMR spectroscopy.

MATERIALS AND METHODS

Ternary GMs of probucol were prepared with PVP (K12, K17, K30 or K90) and SDS at a weight ratio of 1:3:1 and were ground for 15, 30 and 60 min. Solid-state interactions were evaluated using powder X-ray diffraction (PXRD) and solid-state cross polarization/magic angle spinning (CP/MAS) (13)C NMR spectroscopy. A high resolution scanning electron microscopy (SEM) was employed to observe nanoparticles of probucol in the GM.

RESULTS

The solid-state (13)C CP/MAS NMR results indicate that the low molecular weight PVP interacts with probucol and SDS more strongly than the high molecular weight PVP in the ternary GM. This finding was consistent with the result that smaller drug nanoparticles were obtained using low molecular weight of PVP. SEM images of probucol/PVP K12/SDS confirmed the presence of nanoparticles (15-25 nm) in the GM.

CONCLUSIONS

Grinding-induced solid-state interactions among drug, PVP and SDS could be detected using solid state (13)C NMR. The interactions in both probucol-PVP and PVP-SDS should occur simultaneously to generate nanometer-sized particles of probucol.

Polymerized-type I collagen for the treatment of patients with rheumatoid arthritis. Effect of intramuscular administration in a double blind placebo-controlled clinical trial

OBJECTIVE

To determine the efficacy, tolerance and safety of intramuscular injections of porcine type I collagen-PVP in patients with RA in a long term-therapy.

METHODS

The study was a double blind placebo-controlled and included 30 patients with active RA (ACR). Patients were treated with intramuscular injections of 2 ml of collagen-PVP (3.4 mg of collagen) or 2 ml of placebo during 6 months. The follow up was done during the next 6 months. The primary endpoints included the Ritchie index (RI), swollen joint count, disease activity score (DAS), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). The secondary endpoints included morning stiffness, pain intensity on a visual analogue scale (VAS), and Spanish-health assessment questionnaire (HAQ-DI). Improvement was determined using American College of Rheumatology response criteria (ACR20, 50 and 70).

RESULTS

Collagen-PVP was safe and well tolerated. There were no adverse events. Patients had a statistically significant improvement (p < 0.05) in collagen-PVP-treated vs. placebo at 6 months of treatment in: swollen joint count (7.1 +/- 0.8 vs. 16.0 +/- 1.6), RI (8.1 +/- 0.8 vs. 15.2 +/- 1.5), morning stiffness (9.2 +/- 3.1 vs. 29.1 +/- 5.9 min), HAQ-DI (50.0 +/- 10.8 vs. 22.9 +/- 10.3), DAS (3.0 +/- 0.2 vs. 4.9 +/- 0.3), ACR20 (78.6 vs. 71.4%), ACR50 (57.1 vs. 0%) and ACR70 (7.1 vs. 0%) and CRP (1.1 +/- 0.4 vs. 2.5 +/- 0.7). Patients treated with collagen-PVP required lower doses of methotrexate vs. placebo (12.6 +/- 0.6 vs. 14.2 +/- 0.7 at 6 months and 12.3 +/- 0.8 vs. 15.4 +/- 0.6 at 12 months; p < 0.05). Serological or haematological parameters remained unchanged.

CONCLUSION

Collagen-PVP has been shown to be a safe and well-tolerated drug for the long-term treatment of RA. Combination of collagen-PVP plus methotrexate was more efficacious than methotrexate alone. This biodrug can be useful in the treatment of RA.

Promotion of optimized protein therapy by bioconjugation as a polymeric DDS

In recent years, clinical applications of recombinantly produced bioactive proteins such as cytokines have attracted attention. However, since these recombinant proteins are rather unstable in vivo, their clinical use as therapeutic agents requires frequent administration at a high dosage. This regimen disrupts homeostasis and results in severe side effects. To overcome these problems, bioactive proteins have been conjugated with water-soluble synthetic (WSS) polymeric carriers. Chemical modification of a protein with a WSS polymeric carrier (bioconjugation) regulates tissue distribution, resulting in a selective increase in its desirable therapeutic effects and a decrease in undesirable side effects. Among several drug delivery system (DDS) technologies, bioconjugation has been recognized as one of the most efficient methods for improving therapeutic potency of proteins. However, for further enhancement of the therapeutic potency and safety of conjugated bioactive proteins, more precise regulation of the in vivo behavior of each protein is necessary for selective expression of its therapeutic effect. Therefore, alternative WSS polymeric modifiers in which new functions such as targeting and controlled release of drugs can be added are required for further development of bioconjugated drugs. Recently, we have synthesized a novel polymeric drug carrier, poly(vinylpyrrolidone-co-dimethyl maleic anhydride) [PVD], which was a powerful candidate drug carrier for cancer therapy. In this review, we introduce useful information that enabled us to design polymeric drug carriers and their application for protein therapy.

Evaluation of the clinical behaviour of a polyvinylpyrrolidone and sodium hyalonurate gel (Gelclair) in patients subjected to surgical treatment with CO2 laser

This experimental study was undertaken to evaluate the efficacy of Gelclair, a concentrated oral gel consisting of sodium hyalonurate and polyvinylpyrrolidone, in decreasing postoperative pain in patients subjected to surgical treatment by extirpation and/or vapourization of oral lesions with CO(2) laser. After the surgery, 60 consecutive patients (30 in control group and 30 in experimental group) were prescribed 600 mg ibuprofen 3 times per day for 4 days. In the experimental group a protocol was established for the application of 15 ml of Gelclair directly onto the wound 3 times per day, 1 h before meals, for 1 week. Spontaneous pain and pain on swallowing were evaluated using a visual analogue scale at 24 h and 7 days after the intervention. The experimental group had less spontaneous pain at 24h (P=0.000) and at 1 week (P=0.012), and also less pain on swallowing at 24 h and 1 week (P=0.029 and P=0.000, respectively) after the intervention. In conclusion, the effectiveness of the barrier mechanism that Gelclair provides improves the postoperative experience of patients who have undergone oral CO(2) laser surgery.

A technique to improve the safety of laryngeal mask airway when used in lacrimal duct surgery

BACKGROUND

Congenital obstruction of the lacrimal drainage system is present in approximately 6% of newborn. Syringing and probing is one of the common interventional modalities for this condition. Current literature states that syringing and probing is performed best with general anesthesia with tracheal intubation. We study a technique to improve the safety and efficacy of the laryngeal mask airway (LMA) in lacrimal duct surgery.

METHODS

Sixty-five ASA grade I-II patients between 6 months and 10 years scheduled for syringing and probing were included after informed consent was obtained from the parents. After induction of anesthesia and confirmation of LMA position, a transparent suction catheter was inserted into the hypopharynx. Continuous suction was applied to the catheter. A total of 2-3 ml of 0.01% povidone-iodine solution was used for syringing. Staining of the catheter was regarded as a sign of patency of the duct.

RESULTS

None of our patients had perioperative airway or respiratory complications.

CONCLUSIONS

Based on the results of our study, we suggest that the LMA can safely be used in lacrimal duct procedures. Using 0.01% povidone-iodine as irrigation fluid further increases the margin of safety.

[Infusion therapy use in treatment of patients with sialoadenitis and sialadenosis]

The authors treated 42 patients with sialoadenitis and sialadenosis by intravenous drop infusion of hemodes and rheopolyglucin solutions for detoxication and tissue microcirculation improvement. The best results were received with rheopolyglucin (84% of positive response). Infusions of hemodes solution were more effective when used as a component of combined pharmacotherapy of chronic diseases of the salivary glands.

Disorder and dissolution enhancement: Deposition of ibuprofen on to insoluble polymers

Microcrystalline cellulose (MCC) and cross-linked polyvinylpyrrolidone (PVP-CL) were examined as polymeric carriers to support amorphous ibuprofen (IB). Drug/carrier systems were prepared as physical mixes, and drug was loaded onto the polymers by hot mix and solvent deposition methods. The systems were examined using differential scanning calorimetry (DSC), X-ray powder diffractometry (XRD) and by dissolution testing. PVP-CL reduced drug crystallinity more than MCC and, surprisingly, even very simple mixing of ibuprofen with PVP-CL induced disordering of the drug. Increased ibuprofen dissolution rates were achieved with both polymers, in the order of solvent deposition>hot mixes>physical mixes. The increased dissolution rates could be attributed to a combination of faster dissolution from amorphous ibuprofen, microcrystalline drug deposition on carrier surfaces and polymer swelling. However, no clear relationship was observed between ibuprofen dissolution rates (using first order, Higuchi or Hixson-Crowell relationships) and drug crystallinity.

A comparison between povidone-ethylcellulose and povidone-eudragit transdermal dexamethasone matrix patches based on in vitro skin permeation

The present study was designed to develop a suitable matrix type transdermal drug delivery system (TDDS) of dexamethasone using blends of two different polymeric combinations, povidone (PVP) and ethylcellulose (EC) and Eudragit with PVP. Physical studies including moisture content, moisture uptake, flatness to study the stability of the formulations and in vitro dissolution of the experimental formulations were performed to determine the amount of dexamethasone present in the patches were performed and scanning electron microscopy (SEM) photographs of the prepared TDDS were taken to see the drug distribution pattern. Drug-excipient interaction studies were carried out using Fourier transform infrared (FTIR) spectroscopic technique. In vitro skin permeation study was conducted in a modified Franz's diffusion cell. All the formulations were found to be suitable for formulating in terms of physicochemical characteristics and there was no significant interaction noticed between the drug and polymers used. In vitro dissolution studies showed that the drug distribution in the matrix was homogeneous and the SEM photographs further demonstrated this. The formulations of PVP:EC provided slower and more sustained release of drug than the PVP:Eudragit formulations during skin permeation studies and the formulation PVP:EC (1:5) was found to provide the slowest release of drug. Based on the above observations, it can be reasonably concluded that PVP-EC polymers are better suited than PVP-Eudragit polymers for the development of TDDS of dexamethasone.

Physicochemical evaluation of PVP–thiazide diuretic interactions in co-spray-dried composites—analysis of glass transition composition relationships

The aim of this study was to evaluate the possible interactions in the solid state between the thiazide diuretics: bendroflumethiazide (BFMT), hydroflumethiazide (HFMT) and hydrochlorothiazide (HCT) and polyvinylpyrrolidone (PVP) following processing. The glass transition temperatures (T(g)s) of a range of binary co-spray-dried PVP-thiazide composites were determined and compared to the predictions of the Gordon-Taylor, Fox, Couchman-Karasz, Kwei and Schneider equations. The solid composites of the thiazide diuretics and PVP were prepared by a spray drying technique. Properties of composites were determined with the use of helium pycnometry and FTIR spectroscopy. For many systems studied the experimentally detected T(g)s exhibited large positive deviations when compared with the values predicted by the Gordon-Taylor, Fox and Couchman-Karasz equations. The data was better fitted by the Schneider equation consistent with a drug-polymer interaction. FTIR analysis revealed that strong hydrogen bonding between the sulphonamide groups of the thiazide diuretics and the PVP molecule was responsible for the increase in the T(g)s. Additionally, in the case of BFMT-PVP composites, an interaction between the phenyl group and polymer ring was apparent. Glass transition-composition behaviour for amorphous drug-PVP composites deviated from the predictions of the commonly used Gordon-Taylor equation. Deviations were consistent with interactions between the components in the amorphous mixtures. The Schneider equation may be successfully applied to fit the Tg-composition profiles obtained, where other models fail to give good predictions.

Subcutaneous administration of collagen-polyvinylpyrrolidone down regulates IL-1beta, TNF-alpha, TGF-beta1, ELAM-1 and VCAM-1 expression in scleroderma skin lesions

In this study the effect of collagen-polyvinylpyrrolidone (collagen-PVP) vs. triamcinolone acetonide (Triam) in scleroderma (SSc) skin lesions was evaluated. Ten SSc patients were treated weekly with subcutaneous injections of 0.2 mL Triam (8 mg/mL) or 0.2 mL collagen-PVP (1.66 mg collagen). Skin biopsies were obtained from lesions before and after treatment. Tissue sections were evaluated by histology and immunohistochemistry (ELAM-1, VCAM-1, IL-1beta, TNF-alpha, TGF-beta1 and PDGF). The corticoid-treated group showed abnormal tissue architecture while the biodrug-treatment restored cutaneous appendages and type I/III collagen proportion. Cytokine and adhesion molecule expression was almost inhibited with Triam, while collagen-PVP down-regulated it. Collagen-PVP improved the tissue architecture of SSc lesions and down-regulated some proinflammatory parameters, without the side effects induced by corticoids.

[Morphological changes in experimental melanoma B-16 effected by a conjugate of polyvinylpyrrolidone and metal-organic complex of copper and melphalan]

Data on morphological alterations in experimental melanoma B-16 induced by conjugate of polyvinylpyrrolidone and metal-organic complex of copper and melfalon are presented. The antitumor effect of the synthetic conjugate, which inhibits melanoma-16 growth, is adequately tolerated by bone marrow cells. Conjugate accumulation among the dividing cells inhibits the proliferatrive capability of malignant cells and causes other specific morphological changes to occur. It was found that polyvinylpyrrolidone conjugate can be used as a carrier whenever there is a problem of making certain drugs soluble and, thus, more marketable.

The targeting of anionized polyvinylpyrrolidone to the renal system

We reported that the co-polymer composed of vinylpyrrolidone and maleic acid selectively distributed into the kidneys after i.v. injection. To further optimize the renal drug delivery system, we assessed the renal targeting capability of anionized polyvinylpyrrolidone (PVP) derivatives after intravenous administration in mice. The elimination of anionized PVP derivatives from the blood decreased with increasing anionic groups, and the clearance of carboxylated PVP and sulfonated PVP from the blood was almost similar. But carboxylated PVP efficiently accumulated in the kidney, whereas sulfonated PVP was rapidly excreted in the urine. The renal levels of carboxylated PVP were about five-fold higher than sulfonated PVP. Additionally, carboxylated PVP was effectively taken up by the renal proximal tubular epithelial cells in vivo after i.v. injection. These anionized PVP derivatives did not show any cytotoxicity against renal tubular cells and endothelial cells in vitro. Thus, these carboxylated and sulfonated PVPs may be useful polymeric carriers for drug delivery to the kidney and bladder, respectively.

Galactosylated chitosan (GC)-graft-poly(vinyl pyrrolidone) (PVP) as hepatocyte-targeting DNA carrier:in vitro transfection

Galactosylated chitosan-graft-poly(vinyl pyrrolidone) (GCPVP) was synthesized and characterized for hepatocyte-targeting gene carrier. GCPVP itself as well as GCPVP/DNA complex had negligible cytotoxicity regardless of the concentration of GCPVP and the charge ratio, but GCPVP/DNA complex had slightly cytotoxic effect on HepG2 cells only in the case of the higher charge ratio and 20 mM of Ca2+ concentration used. Through the confocal laser scanning microscopy, it is shown that the endocytosis by interaction between galactose ligands of GCPVP and ASGPR of the hepatocytes was the major route of transfection of GCPVP/F-plasmid complexes.

Rapid induction of splenic and peritoneal B-1a cells in adult mice by thymus-independent type-2 antigen

We have produced a transgenic mouse (PV1TgL) that can only generate B lymphocytes with an Ig receptor specific for the synthetic polymer polyvinyl pyrrolidinone. Before immunization, bone marrow B cell numbers are very low, and peripheral lymphoid organs are almost devoid of B cells, confirming the role of positive selection by Ag in the development of mature B cell populations. The predominant population of B cells in the spleens of naive adult PV1TgL mice have most of the characteristics of marginal zone B cells, including anatomical location in the peripheral areas of the splenic white pulp. After immunization, a new population of B cells appears in the spleen with the characteristics of B-1 cells. Similar cells also appear somewhat later in the peritoneal cavity. Our findings suggest that immunization with a thymus-independent Ag can lead to the appearance and expansion of Ag-reactive B-1 cells in an adult mouse.

The use of PVP as a polymeric carrier to improve the plasma half-life of drugs

To achieve an optimum drug delivery such as targeting or controlled release utilizing bioconjugation with polymeric modifier, the conjugate between drugs and polymeric modifiers must be designed to show desirable pharmacokinetic characteristics in vivo. In this study, we assessed the biopharmaceutical properties of various nonionic water-soluble polymers as polymeric drug carriers. Polyvinylpyrrolidone (PVP) showed the longest mean resident time (MRT) after i.v. injection of all nonionic polymers with the same molecular size. In fact, tumor necrosis factor-alpha (TNF-alpha) bioconjugated with PVP (PVP-TNF-alpha) circulated longer than TNF-alpha bioconjugated with polyethylene glycol (PEG-TNF-alpha) with the same molecular size. Each nonionic polymeric modifier showed a different tissue distribution. Dextran was accumulated in the spleen and liver. Polydimethylacrylamide (PDAAm) tended to distribute in the kidney. However, PVP showed the minimum volume of tissue distribution. These results suggested that PVP is the most suitable polymeric modifier for prolonging the circulation lifetime of a drug and localizing the conjugated drug in blood.

[Studies on combined release behaviors of versatile mini-tablets in capsule systems and fittings of their mathematical model]

AIM

To prepare nifedipine (NP) rapid release mini-tablet, sustained release mini-tablets, pulsed release mini-tablets and delayed-onset sustained release mini-tablets and develop multiplied pulsed drug delivery system (DDS), site-specific DDS, zero-order DDS and quick/slow DDS by various ways.

METHODS

Velocity-time (v-t) equation of each mini-tablet was deduced by non-linear least square model fit. The difference of combinations in v-t profiles between theoretical value and test value was compared.

RESULTS

According to the v-t equations, the combined release behaviors were observed directly from v-t profiles and the test values coincided with the theoretical profiles.

CONCLUSION

The programmed DDS, which consist of a variety of mini-tablets with different dosages and combinations in capsules, could be predicted by summing up the v-t equation of each tablet.

[Improvement of curative measures for peritonites of obstetric and gynecological etiology]

The authors describe results of treatment of 117 patients with obstetric and gynecological peritonites. The first group consisted of 43 patients treated by conventional methods. The second group included 74 patients treated by unguent sanitation of the abdominal cavity and prolonged intraarterial catheter (PIAC) against the background of unguent sanitation. The unguent sanitation of the abdominal cavity with water-soluble antibacterial ointments has decreased the number of intra-abdominal and extra-abdominal complications. However in especially severe cases and at high virulence of the abdominal cavity microflora the application of the unguent sanitation alone was not sufficiently effective. So, in 19 patients PIAC was used by the developed scheme. The complex treatment with the unguent sanitation of the abdominal cavity and PIAC allowed to perform the adequate sanitation of the abdominal cavity with lower microbe dissemination of the abdominal cavity up to the critical level on the third day after operation and resulted in less number of intra-abdominal complications from 39.0 to 19.6%, extra-abdominal complications from 15.0 to 7.5% and lethality from 23.2 to 10.8%.

Effect of Povidone 2% Preservative-free Eyedrops on Contact Lens Wearers With Computer Visual Syndrome:

PURPOSE

To show that the use of povidone 2% preservative-free lubricating eyedrops reduces computer visual syndrome in contact lens wearers and to identify the best eyedrop instillation protocols.

METHODS

The test product was FILMABAK a CE-marked nonpreserved lubricant, povidone 2% delivered by the ABAK system. Three dispensing modalities were evaluated during contact lens wear and computer use: hourly instillation, symptom-related instillation, and patient's own instillation.

RESULTS

During sustained computer use, a decrease in symptoms associated with the use of povidone 2% was statistically and clinically significant. However, the symptoms were not fully eliminated by the use of the test eyedrop. The three instillation routines achieved similar beneficial effects. No significant changes in ocular tissue response were observed, and the staining recorded after sustained computer use remained low. The use of povidone 2% preservative-free lubricating eyedrops under any of the three instillation modalities tested was also associated with a slight improvement in dynamic visual acuity.

CONCLUSIONS

The use of povidone 2% preservative-free eyedrops was associated with an improvement in symptoms during sustained computer use. Any of the three instillation modalities decreased symptoms of ocular tiredness, dryness, and difficulty of focus; maintained an unchanged corneal surface; and improved dynamic visual acuity. Therefore, the most patient-friendly modality (patient's own instillation modality from symptom onset) could be recommended to contact lens wearers with computer visual syndrome.

Cellular and humoral responses to collagen–polyvinylpyrrolidone administered during short and long periods in humans

Collagen, particularly type I, and its related derivatives have been extensively employed in many areas of pharmacology. The present study was performed to determine the safety of collagen–polyvinylpyrrolidone (collagen–PVP) by in vitro and in vivo studies. Sera and peripheral blood cells from healthy donors without treatment and patients treated with collagen–PVP were evaluated. We observed that the biodrug does not stimulate lymphoproliferation or DNA damage in vitro, nor does it induce human anti-porcine type I collagen or anti-collagen–PVP antibodies in vivo. Furthermore, no hepatic or renal metabolic dysfunctions were observed when collagen–PVP was administered by intradermal or intramuscular routes in short- or long-term treatments. In conclusion, the present work shows that no cellular damage or immunological adverse effects (cellular and humoral) occurred during collagen–PVP treatment, even after more than 400 weeks of consecutive administrations.Key words: collagen–polyvinylpyrrolidone, DNA damage, collagen antibodies, hypertrophic scar.