Dissolving Microneedles Loaded with Gestodene: Fabrication and Characterization In Vitro and In Vivo.

Background: Gestodene (GEST) is widely used in female contraception. It is currently being used as an oral contraceptive. However, unfortunately, oral contraceptives are often associated with several bothersome side effects and poor compliance. Therefore, a sustained delivery system for GEST to overcome these shortcomings is highly desirable. Objectives: The present study successfully developed a kind of novel dissolving microneedles (DMNs) with a potential for sustained release and a minimally invasive intradermal treatment of GEST. Methods: The dissolving microneedles containing GEST were fabricated using polyvinylpyrrolidone as the base material. The characteristics in vitro and pharmacokinetics in vivo of GEST-loaded DMNs were investigated. Results: The results showed that the microneedle could pierce the porcine skin and release the drug at an average dose of 20µg/cm2 daily for seven days. The pharmacokinetic experiment of the microneedles indicated that the plasma level of GEST in rats increased with increasing drug dosage, and the plasma drug concentration-time curves were much flatter compared with subcutaneous injection and oral administration. In addition, no cutaneous irritation was observed. Conclusions: GEST-loaded DMNs may be a promising intradermal sustained delivery system for contraceptive use.

Knockdown of ASF1B inhibits cell proliferation, migration, invasion and cisplatin resistance in gastric cancer through the Myc pathway.

Gastric cancer (GC) is a prevalent malignancy in the digestive system that poses a serious threat to human health. Anti-silencing function 1B (ASF1B) performs an important role in the progression of numerous tumors; however, its function in GC still requires further elucidation. Using data from The Cancer Genome Atlas, the expression levels of ASF1B in GC tissues were analyzed and a survival curve for high-ASF1B expression and low-ASF1B expression groups was plotted using the Kaplan-Meier method. Reverse transcription-quantitative PCR was performed to evaluate ASF1B expression in GC tissues and cells. Small interfering RNAs targeting ASF1B were transfected into HGC-27 and AGS cells to silence ASF1B expression. Cell viability, proliferation, migration, invasion, and apoptosis in HGC-27 and AGS cells was assessed using cell counting kit-8 assay, colony formation assay, wound healing assay, Transwell assay and flow cytometry, respectively. The protein changes were assessed using western blotting. Gene Set Enrichment Analysis (GSEA) was used to identify ASF1B related pathways. The results demonstrated that ASF1B expression was increased in GC tissues and cells compared with adjacent healthy tissues and normal cells (GES-1), and high expression of ASF1B was associated with poor survival outcomes in patients with GC. Silencing ASF1B inhibited cell viability, colony formation, migration, invasion and cisplatin resistance, while also attenuating the apoptotic capability of HGC-27 and AGS cells. GSEA showed that ASF1B could activate the Myc-targets-v1 and Myc-targets-v2 pathways. Moreover, silencing ASF1B inhibited the Myc pathway-related proteins Myc, minichromosome maintenance (MCM)4 and MCM5. Overexpression of Myc reversed the inhibitory effect of ASF1B silencing on AGS cell proliferation, invasion and cisplatin resistance. In conclusion, the results indicate that knockdown of ASF1B may suppress GC cell proliferation, migration and invasion, and promote cell apoptosis and cisplatin sensitivity by modulating the Myc pathway, thereby offering novel possibilities for reversing cisplatin resistance in GC.

A novel anastrozole intravaginal ring for endometriosis: Pharmacokinetic characteristics and mucosal irritation.

In order to achieve the long-term management of endometriosis, a more economical and environmentally friendly material, ethylene vinyl acetate (EVA), was used to prepare a intravaginal ring with anastrozole (ATZ). This paper has compared the pharmacokinetic parameters with oral tablets (Aida®) in mini pigs and evaluated the uterine targeted effect and mucosal irritation of the ring. A bioassay method was developed and validated for the determination of ATZ in mini pigs. The determination of ATZ was achieved by LC-MS/MS using terfenadine as the internal standard. Separation was achieved on a Kinetex-C18 110A chromatographic column (3 × 30 mm, 2.6 µm; Phenomenex) with a gradient mobile phase consisting of methanol (0.1% formic acid) and water (0.1% formic acid). The method has been proved to be scientific and sensitive through methodological validation and can be easily and quickly applied to the determination of the content of anastrozole in mini pigs. The pharmacokinetic test results show that there was no significant difference in pharmacokinetic parameters between the two formulations. The intravaginal ring has a passive targeting effect on the uterus, and its mucosal irritation is acceptable. The intravaginal ring provides a new method for long-term management of endometriosis.

Hyperthermic Intraperitoneal Chemotherapy plus Intravenous Chemotherapy of Paclitaxel with or without Sintilimab in Gastric Cancer: A Comparative Study.

OBJECTIVE: To compare the clinical efficacy of hyperthermic intraperitoneal chemotherapy (HIPEC) plus intravenous chemotherapy of paclitaxel with or without sintilimab in peritoneal metastasis of gastric cancer. METHODS: A total of 120 patients assessed for eligibility with peritoneal metastasis of gastric cancer treated in the oncology department of our hospital from January 2019 to June 2020 were recruited. They were concurrently randomly assigned in a 1 : 1 ratio to receive HIPEC plus sintilimab-paclitaxel intravenous chemotherapy (study group) or plus paclitaxel intravenous chemotherapy only (control group). RESULTS: The objective remission rate (ORR) of ascites in the study group was significantly higher than that in the control group. Subgroup analysis showed that an age ≤60 years or well-differentiated tumors were associated with better objective remission. After treatment, significantly higher Karnofsky Performance Status (KPS) scores were observed in the study group versus those of the control group. Adverse events reported were comparable between groups. The study group obtained longer 12-month progression-free survival (PFS) and overall survival (OS) than those of the control group. CONCLUSION: On top of HIPEC, intravenous chemotherapy with sintilimab and paclitaxel constitute an effective alternative for patients with peritoneal metastasis of gastric cancer to enhance ascites remission, ameliorate the quality of life, and prolong survival, versus with paclitaxel alone.

Systematic analysis and molecular profiling of EGFR allosteric inhibitor cross-reactivity across the proto-oncogenic ErbB family kinases by integrating dynamics simulation, energetics calculation and biochemical assay.

Human ErbB family of proteins contains four receptor tyrosine kinases (EGFR, Her2, Her3 and Her4) and has been established as a group of attractive druggable targets against diverse cancers. Over the past decades, a variety of ATP-competitive inhibitors have been discovered to target the orthosteric site of EGFR, which, however, would eventually develop acquired drug resistance due to the missense mutations T790M/C797S occurring in orthosteric site. In recent years, a number of forth-generation inhibitors have been successfully designed to overcome the T790M/C797S-induced drug resistance by targeting EGFR allosteric site instead of orthosteric site. Considering that the four proto-oncogenic ErbB kinases share a high conservation in sequence, structure and function, we herein attempted to investigate the binding potency and cross-reactivity of cognate EGFR allosteric inhibitors over noncognate Her2, Her3 and Her4 kinases--they are closely related to gynecological tumors such as ovarian cancer but no allosteric inhibitors have been reported specifically for them to date. A systematic affinity profile of 12 allosteric inhibitors and 4 orthosteric inhibitors to the 4 ErbB kinases was created by integrating dynamics simulations, energetics calculations and biochemical assays, which was then used to derive a systematic inhibitor selectivity profile for EGFR over other three kinases. It is found that allosteric and orthosteric inhibitors exhibit moderate and modest cross-reactivity across the ErbB family, respectively, but the former generally has a higher binding potency than the latter due to the additional energy cost used for inducing kinase conformational change. Moreover, most allosteric inhibitors can be sensitized by Her2 T798M gatekeeper mutation, a counterpart of EGFR T790M gatekeeper mutation that has been previously reported to cause generic drug resistance for orthosteric inhibitors.

LncRNA PITPNA-AS1 promotes gastric cancer by increasing SOX4 expression via inhibition of miR-92a-3p.

BACKGROUND: Gastric cancer (GC) is a malignant tumor of digestive tract with high mortality. Elucidating the molecular mechanisms of GC and obtaining new molecular targets are particularly important for the prevention and treatment of GC. The discovery of long non-coding RNAs (lncRNAs) provides the possibility for further elucidating the molecular mechanisms of GC and discovering new molecular markers. AIM: Here, we aimed to explore the function and the mechanism of lncRNA PITPNA-AS1 in GC. METHODS: High-throughput lncRNA microarray was used to compare the differences in expression profiles between tumor tissues and adjacent tissues, and to filtrate the differentially expressed lncRNAs in tumors. To analyze the relationship between lncRNA expression and clinicopathological parameters in GC. The apoptosis was detected by down-regulation of lncRNA. The effect of down-regulated lncRNA PITPNA-AS1 on the migration and invasion of GC cells was determined by wound healing and Transwell assays. The function of lncRNA PITPNA-AS1 on tumor growth was verified by tumor experiment in nude mice. Analysis of target interaction relationship was performed by luciferase assay. RESULTS: The results of high throughput chip analysis identified that PITPNA-AS1 was up-regulated in GC tissues. Our data revealed that knockdown of PITPNA-AS1 was able to inhibit tumor development of GC cells. Meanwhile, PITPNA-AS1 could regulate SOX4 expression via targeting miR-92a-3p. CONCLUSION: Thus, we concluded that PITPNA-AS1 induced the development of GC cells by inhibiting miR-92a-3p and inducing SOX4. Our finding presents novel insights of GC, which may provide an underlying therapeutic target for GC treatment.

LC-MS/MS quantification of progesterone in ovariectomized miniature swine and its application for preliminary pharmacokinetic study of a novel vaginal sustained release system.

OBJECTIVE: We here established a simple, fast, robust and sensitive LC-MS/MS method and validated as well for the quantitative analysis of progesterone (PGT) in ovariectomized (OVX) miniature swine plasma. The method was successfully applied to characterize the pharmacokinetics of a progesterone vaginal drug delivery system. METHODS: Megestrol acetate was utilized as an internal standard (IS). The separation and detection of PGT from endogenous interference was performed successfully by liquid chromatography with gradient elution and mass spectrometry equipped with positive ESI source using MRM mode. The EVA intravaginal rings (IVRs) were manufactured by hot-melt extrusion (HME), afterward were administrated vaginally to OVX minipigs to evaluate PK study. RESULTS: The calibration curve for swine plasma samples across the concentration ranged between 0.25 ng/mL and 100 ng/mL. The intra- and inter-assay accuracy and precision were lower than ±5% and 5.88%, respectively. Recoveries of PGT and IS were ranging from 114-119% and 96.5-112%, respectively. In vitro study showed that the EVA IVRs release 18 mg/day of PGT continuously over 7 days, and corresponding mean PGT plasma concentration in OVX minipigs (CAVG) was 4.892 ng/mL. CONCLUSION: All the study produced reliable results for the measurement of PGT concentration in miniature swine plasma and the method was successfully applied to a PK study for PGT vaginal ring in miniature pigs, which may lay the foundation for further research on the progesterone preparations intended for in assisted reproductive technology.

MicroRNA-448 targets SATB1 to reverse the cisplatin resistance in lung cancer via mediating Wnt/ß-catenin signalling pathway.

This study aims to examine whether miR-448 reverses the cisplatin (DDP) resistance in lung cancer by modulating SATB1. QRT-PCR and immunohistochemistry were used to examine the miR-448 and SATB1 expressions in DDP-sensitive and -resistant lung cancer patients. A microarray was used to investigate the cytoplasmic/nucleic ratio (C/N ratios) of genes in A549 cells targeted by miR-448, followed by Dual-luciferase reporter gene assay. A549/DDP cells were transfected with miR-448 mimics/inhibitors with or without SATB1 siRNA followed by MTT assay, Edu staining, flow cytometry, qRT-PCR and western blotting. MiR-448 was lower but SATB1 was increased in DDP-resistant patients and A549/DDP cells. And the patients showed low miR-448 expression or SATB1 positive expression had poor prognosis. SATB1, as a target gene with higher C/N ratios (>1), was found negatively regulated by miR-448. Besides, miR-448 inhibitors increased resistance index of A549/DDP cells, promoted cell proliferation, increased cell distribution in S phrase, declined cell apoptosis and activated Wnt/ß-catenin pathway. However, SATB1 siRNA could reverse the above effect caused by miR-448 inhibitors. MiR-448 targeting SATB1 to counteract the DDP resistance of lung cancer cells via Wnt/ß-catenin pathway.

Lycorine inhibited the cell growth of non-small cell lung cancer by modulating the miR-186/CDK1 axis.

AIMS: Lycorine is a kind of natural alkaloid with anti-cancer potential. It has been demonstrated that lycorine processes high activity and specificity against the progression of cancers. However, the underlying molecular mechanisms by which lycorine regulates the formation and development of non-small cell lung cancer (NSCLC) remain largely unknown. MAIN METHODS: The effects of lycorine on the growth of NSCLC cells were determined by the cell counting kit-8 (CCK-8) assay, colony formation and flow cytometry analysis. RT-qPCR was performed to detect the expression of microRNA with lycorine treatment. The binding of miRNA and target genes was confirmed by luciferase reporter assay. KEY FINDINGS: Lycorine significantly inhibited the proliferation and induced apoptosis of NSCLC cells. Mechanistically, lycorine up-regulated the expression of microRNA-186 in NSCLC cells. Depletion of miR-186 significantly reversed the suppressive effect of lycorine on the proliferation of NSCLC cells. Furthermore, the cyclin dependent kinase 1 (CDK1) was identified as one of the binding candidates of miR-186. Experimental analysis showed that miR-186 bound the 3'-untranslated region (3'-UTR) of CDK1 and suppressed the level of CDK1 in NSCLC cells. Consistently, exposure of lycorine significantly decreased the expression of CDK1. Restoration of CDK1 remarkably attenuated the inhibition of lycorine on the proliferation of NSCLC cells. SIGNIFICANCE: Our results uncovered the novel molecular mechanism of lycorine in suppressing the progression of NSCLC partially via regulating the miR-186/CDK1 axis.

Preparation and in vitro/in vivo evaluation of anastrozole reservoir-type intravaginal ring.

This report details the preparation of anastrozole (ATZ) reservoir-type intravaginal ring (IVR) and the detection of the concentration of ATZ in beagle dog plasma by liquid chromatography-tandem mass spectrometry (LC-MS/MS). An ATZ reservoir-type IVR which included ATZ silicone elastomer core and a nonactive silicone layer was manufactured by reaction injection moulding at 80°C for 20 min. An in vitro release experiment was performed under sink conditions and the samples were determined by high-performance liquid chromatography. A bioanalytical method was developed and validated for determination of ATZ in beagle dog plasma for IVR development. The analytical method consisted of the extraction of plasma samples and determination of ATZ by LC-MS/MS using buspirone as the internal standard. Separation was achieved on a Kinetex-C18 110A column (3 × 30 mm, 2.6 µm, Phenomenex) using step-gradient mobile phase and an isocratic flow rate consisting of formic acid. Protonated ions formed by a turboion spray in the positive mode was used to detect the analyte (ATZ) and internal standard. The MS-MS detection was performed on a triple quadrupole mass spectrometer equipped with electrospray ionization source. The mass spectrometer was operated in the multiple reaction monitoring mode. The mass transition ion-pair was followed as m/z from 294.10 to 225.08 for anastrozole and m/z from 386.23 to 122.11 for buspirone. The results proved that the correlation between in vitro and in vivo analyses was relatively good.

[Silicification of silk fibroin and their application in bone tissue engineering].

In bone tissue engineering, fabrication of scaffold materials that are biodegradable with regenerative functions is one of the most important research fields. Silk fibroin exhibits many favorable characteristics used as scaffold materials. Among them, hybrid silk fibroin/inorganic composites prepared by biomimetic mineralization have better biocompatibility, biomechanical properties, and biodegradability. At the same time, the hybrid silk fibroin/inorganic materials have much better osteoinduction and conduction properties than silk fibroin. Here, the recent advances in the preparation of silk fibroin/silica hybrid materials by combination or biomimetic silicification are reviewed, and the future research prospects of silicification of silk fibroin are discussed.

Quantitative determination of levonorgestrel in beagle dog plasma after vaginal administration of intravaginal ring by high-performance liquid chromatography-tandem mass spectrometry.

A specific and sensitive high-performance liquid chromatography-tandem mass spectrometry method that could be used to determine the concentration of levonorgestrel (LNG) in beagle dog plasma was developed. Specifically, terfenadine was used as the internal standard (IS). The separation was achieved on a Kinetex-C18 110A column (3 × 30 mm i.d., 2.6 um, Phenomenex) and a gradient mobile phase consists of methanol (0.1% formic acid) and water (0.1% formic acid) was used. The flow rate was 0.8 mL/min and the injection volume was 10 µL. The detection was performed on a triple-quadruple tandem mass spectrometer by multiple reaction monitoring mode via electrospray ionization. Quantitative analysis was carried out at m/z 313.0 → 108.9 and m/z 472.6 → 436.2 for LNG and IS respectively. This method demonstrated the linearity of LNG over a concentration range of 0.5-50 ng/mL with a coefficient correlation (r) of 0.9973. The lower limit of quantification was 0.5 ng/mL. The intra- and inter-assay precisions were 2.9 and 11.2%, with an accuracy range from 94.8 to 108.4%. The stability data indicated that sample preparation and storage process had little effect on the concentration of LNG QC sample. The validated method was successfully applied to study the pharmacokinetics of LNG in beagle dog after vaginal administration of intravaginal ring.

Preparation and in vitro/in vivo evaluation of gestodene (GEST) intravaginal ring.

Preparation and in vitro/in vivo evaluation of gestodene (GEST) intravaginal ring (IVR) formulations which can release a constant dose of GEST during 3 weeks were investigated. In present study a reservoir gestodene intravaginal ring, including a gestodene silicone elastomer core and the non-active silicone layer, was reported, which was manufactured by reaction injection moulding at 80°C for 20 min. The raw materials compatibility experiments showed that the silicone elastomer core carrier wouldn't interact with drugs. In vitro release samples were determined by HPLC and the experiment was performed under sink conditions. The equation of cumulative release verse time was Y=64.76χ+5.44 (r=0.9998), performing zero-order release at about the target dose of 60 µg/day over 21 days. Drug release increased with temperature elevating from 45 to 55°C, which could be attributed to optimizing the prescription. In addition, the pharmacokinetic and safety studies of gestodene intravaginal ring were evaluated in female New Zealand White rabbits. The GEST in plasma was analyzed by LC-MS/MS and the results proved that the correlation between in vitro and in vivo was relatively well.

[Preparation and release mechanism of gestodene reservoir-type intravaginal rings].

This study taking gestodene (GEST) as a model, investigated the factors affecting reservoir-type intravaginal ring (IVR)'s drug release. This paper reported a gestodene intravaginal ring of reservoir design, comprising a gestodene silicone elastomer core encased in a non-medicated silicone sheath, separately manufactured by reaction injection moulding at 80 degrees C and heating vulcanization at 130 degrees C is reported. The test investigated the factors affecting drug release through a single variable method, taking the drug release rates of 21 days as standards. When changing the thickness of the controlling sheath outside, the ratio of the first day of drug release and mean daily release (MDR), named the relatively burst effect, is closing to 1 with the thickness of controlling sheath increasing, while the 1.25 mm sheath corresponding to 1.04 controlled the burst release effectively; a positive correlation (r = 0.992 2) existed between the average drug release (Q/t) and drug loading (A) within a certain range. The C6-165 controlling sheath with high solubility of GEST is easier to achieve controlled release of the drug; GEST crystalline power is more effective to implement controlled release of drugs among difficent states of the drug. A 1/4 fractional segment core gives a relatively burst effect of 1.76, while the 1/1 and 1/2 are 1.93 and 1.87 separately, at the same drug loading, concluding that use of a fractional segment core would allow development of a suitable GEST reservoir IVR. In summary, GEST reservoir-type IVR could be adjusted by the thickness of controlling sheath, the loading of drug, the material properties of controlling sheath, the dispersion state of drug, the additive composition and structure of intravaginal ring, to control the drug release behavior and achieve the desired drug release rate.

Preparation and evaluation of intravaginal ring containing drospirenone.

In the present study, we investigated the feasibility of the vaginal administration of drospirenone silicone IVR. The in vitro release characteristics of matrix-type and reservoir-type IVR were compared under sink conditions in 21 days. At the same time, API excipients compatibility and preformulation study was performed by HPLC, IR, and DSC methods. Biocompatibility of reservoir system was evaluated by tolerability on tissue level in rats. It was found that, under strong light exposure, high temperature, and high humidity conditions, drospirenone and excipients had no significant interactions. The daily release of reservoir-type IVR was about 0.5 mg/d sustaining 21 days, which significantly decreased the burst effect compared with the matrix system. When drospirenone was modified by the PVPk30 in the reservoir system formulation, the daily release rate increased to 1.0 mg/d sustaining 21 days. The cumulative release of reservoir-type IVR was fitted to zero release equation. In addition, biocompatibility of drospirenone IVR system in this dosage is safe. It is feasibility feasibile to further developed for safe, convenient, and effective contraceptive drug delivery with reduced dosing interval.

Preparation and in vitro/in vivo evaluation of vinpocetine elementary osmotic pump system.

Preparation and in vitro and in vivo evaluation of vinpocetine (VIN) elementary osmotic pump (EOP) formulations were investigated. A method for the preparation of VIN elementary osmotic pump tablet was obtained by adding organic acid additives to increase VIN solubility. VIN was used as the active pharmaceutical ingredient, lactose and mannitol as osmotic agent. Citric acid was used as increasing API solubility and without resulting in the API degradation. It is found that the VIN release rate was increasing with the citric acid amount at a constant range. Cellulose acetate 398-3 was employed as semipermeable membrane containing polyethylene glycol 6000 and diethyl-o-phthalate as pore-forming agent and plasticizer for controlling membrane permeability. In addition, a clear difference between the pharmacokinetic patterns of VIN immediate release and VIN elementary osmotic pump formulations was revealed. The area under the plasma concentration-time curve after oral administration of elementary osmotic pump formulations was equivalent to VIN immediate release formulation. Furthermore, significant differences found for mean residence time, elimination half-life, and elimination rate constant values corroborated prolonged release of VIN from elementary osmotic pump formulations. These results suggest that the VIN osmotic pump controlled release tablets have marked controlled release characters and the VIN osmotic pump controlled release tablets and the normal tablets were bioequivalent.

Niosomes with sorbitan monoester as a carrier for vaginal delivery of insulin: studies in rats.

To prepare and investigate the potential of the niosomes vaginal delivery system for systemic treatment of insulin is the goal of this study. Two kinds of vesicles with Span 40 and Span 60 were prepared by lipid phase evaporation methods with sonication. The niosomal entrapment efficiency was determined by column chromatography. The particle size and morphology of the vesicles also were evaluated. The results showed optimized niosomes prepared in this study had niosomal entrapment efficiency 26.68 +/- 1.41% for Span 40 and 28.82 +/- 1.35% for Span 60, respectively. The particle sizes of Span 40 niosomes and Span 60 niosomes were 242.5 +/- 20.5 nm and 259.7 +/- 33.8 nm, respectively. There were no significant differences in appearance between the two types of vesicles. The hypoglycemic effects, and insulin concentrations after vaginal administration of insulin vesicles to rats were investigated. Compared with subcutaneous administration of insulin solution, the relative pharmacological bioavailability and the relative bioavailability of vaginal administration of insulin vesicles were determined. Compared with subcutaneous administration of insulin solution, the relative pharmacological bioavailability and the relative bioavailability of insulin-Span 60 vesicles group were 8.43% and 9.61%, and insulin-Span 40 niosomes were 9.11% and 10.03% (p > 0.05). Span 60 and Span 40 niosomes were both higher than blank Span 40, Span 60 vesicles, and free insulin physical mixture groups (p < 0.05). The results indicates insulin-Span 60, Span 40 niosomes had an enhancing effect on vaginal delivery of insulin. Although the factors controlling the process for penetration of a portion of vaginally administrated niosomes into bloodstream from vaginal tract is still not fully understood, our results demonstrated that after encapsulation in niosomes of definite type, insulin became an active and efficiently therapeutic agent when administrated vaginally and might be a good carrier for vaginal delivery of protein drugs.

Preparation, in vitro and in vivo evaluation of liposomal/niosomal gel delivery systems for clotrimazole.

Clotrimazole, which is an imidazole derivative antifungal agent, was widely used for the treatment of mycotic infections of the genitourinary tract. To develop alternative formulation for the vaginal administration of clotrimazole to provide sustained and controlled release of appropriate drug for local vaginal therapy, liposomes/niosomes were evaluated as delivery vehicles. To optimize the preparation of liposomes/niosomes with regard to size and entrapment efficiency, multilamellar liposomes/niosomes containing drug were prepared by lipid hydration method. The prepared liposomes/niosomes were incorporated into 2% carbopol gel, and the systems were evaluated for drug stability in phosphate-buffered saline (pH 7.4) and simulated vaginal fluid at 37 +/- 1 degrees C. Further, the vesicle gel system was evaluated by antifungal activity and tolerability on tissue level in rat.

Preparation and evaluation of proliposomes containing clotrimazole.

Clotrimazole (CT)-containing proliposomes were prepared by penetrating an ethanol solution of CT and Egg phosphatidylcholine (PC) into microporous sorbitol particles, followed by vacuum evaporation of the solvent. As a result, CT proliposomes with free-flowing flowability were obtained. On contact with water, the proliposomes were rapidly converted into a liposomal dispersion, in which a certain amount of CT was entrapped by the liposomes. The result in scanning electronic micrograph confirmed the formation of liposomes structures from proliposomes, and the particles revealed round or ellipse. The ratio of drug to total lipid, ratio of PC to cholesterol and ratio of lipid to sorbitol affected the entrapment efficiency (EE%). The EE% of optimized formulation (CT 10 mg, 0.1 g total lipid, PC/CH ratio is 60 : 40 and 1 g sorbitol) in this investigation was 96.2+/-1.5%. The proliposomes system can provide sustaining release in simulated vaginal fluid at 37+/-1 degrees C for 24 h. In-vivo performance of blank proliposomes, a physical mixture of sorbitol and drug, clotrimazole proliposomes and commercial ointment formulation were evaluated using antifungal activity test. At 7 d post-dose, the c.f.u. of C. albicans decreased in proliposomes-treated groups than ointment and the physical mixture (t-Student, p<0.05). The results indicated that CT-containing vaginal proliposomes prolonged drug release and may increase amount of drug retention into the mucosa to result in more antifungal efficacy. In addition, CT-proliposomes did not affect the morphology of vaginal tissues. Therefore, the dosage form might be further developed for safe, convenient, and effective treatment of vaginal candidasis with reduced dosing interval.