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At least 19 recordsLinked to original sources
PubMed1991

Treatment of leiomyomata uteri with leuprolide acetate depot: a double-blind, placebo-controlled, multicenter study. The Leuprolide Study Group.

The purpose of this study was to evaluate efficacy and safety parameters in women with leiomyomata uteri treated with the GnRH agonist leuprolide acetate depot, 3.75 mg intramuscularly every 4 weeks for 24 weeks. One hundred twenty-eight patients were enrolled in a randomized, double-blind, placebo-controlled multicenter study involving 13 investigative centers. Mean uterine volume decreased by 36% at 12 weeks and 45% at 24 weeks of leuprolide therapy. Patients treated with placebo had increased in mean uterine volume of 16% at 12 weeks and 5% at 24 weeks. Seventy-seven percent of leuprolide-treated patients had a more than 25% reduction in uterine volume, compared with 9% of placebo-treated controls. Mean uterine volume returned to pre-treatment size 24 weeks after cessation of leuprolide treatment. The majority of patients had resolution or improvement of their fibroid-related symptoms after 24 weeks of leuprolide treatment. Of 38 leuprolide-treated patients presenting with menorrhagia, 37 (97%) had resolution of this symptom at the time of the final visit. Although 95% of women treated with leuprolide acetate experienced some side effects related to hypoestrogenism, only five patients (8%) terminated treatment prematurely. We conclude that leuprolide acetate depot treatment of leiomyomata uteri is safe and causes significant but temporary reductions in uterine size and fibroid-related symptoms.

Adult↗
PubMed1995

Subcutaneous low dose leuprolide acetate depot versus leuprolide acetate for women undergoing ovarian stimulation for in-vitro fertilization.

A total of 100 women undergoing ovarian stimulation with gonadotrophin-releasing hormone agonist (GnRHa) and a human menopausal gonadotrophin (HMG) for in-vitro fertilization (IVF) participated in this randomized comparative study. Leuprolide acetate at a dose of 0.5 mg/day s.c. (n = 52, group I), or low-dose leuprolide acetate depot at a dose of 1.88 mg s.c. (n = 48, group II), was started on days 21-23 of the cycle. Stimulation with 225 IU/day HMG was started after pituitary desensitization had been achieved. The luteal phase was supported by human chorionic gonadotrophin (HCG) i.m. injection. There were no statistical differences in baseline oestradiol (24.5 +/- 4.8 versus 21.9 +/- 4.5 pg/ml) and follicle stimulating hormone (FSH) concentrations (3.9 +/- 1.9 versus 3.2 +/- 1.8 mIU/ml), and concentrations on the day of HCG administration of oestradiol (1657 +/- 245 versus 1512 +/- 165 pg/ml), luteinizing hormone (LH; 6.2 +/- 4.8 versus 5.6 +/- 4.3 mIU/ml) and FSH (10.6 +/- 2.8 versus 10.8 +/- 3.6 mIU/ml). There were also no statistical differences in the HMG dosage (26.8 +/- 1.8 versus 28.5 +/- 1.5), the number of oocytes retrieved (7.6 +/- 3.0 versus 8.1 +/- 4.3), the number of oocytes fertilized (5.3 +/- 2.1 versus 5.6 +/- 3.0) and the number of embryos transferred (3.5 +/- 1.3 versus 3.4 +/- 1.6). There was no evidence of a premature LH surge in either group, but two patients appeared to have a poor response in the leuprolide acetate group (group I). There were 11 pregnancies (21.2%) after the use of leuprolide acetate and 12 pregnancies (25.0%) in those given leuprolide acetate depot; no statistical difference existed between these two groups. Thus, a s.c. low-dose leuprolide acetate depot injection may offer a useful alternative for pituitary suppression in ovarian stimulation for IVF.

Adult↗
PubMedDate not supplied

Heterostereocomplexes prepared from d-PLA and l-PLA and leuprolide. II. Release of leuprolide.

Reversible stereoselective complexes were spontaneously obtained from mixing acetonitrile solutions of enatiomeric d-poly(lactic acid) (d-PLA), l-poly(lactic acid) (l-PLA), and leuprolide, a l-configured nonapeptide LHRH analogue. The complex spontaneously aggregated and precipitated in high yields (>90%) from acetonitrile solution, forming uniform, porous microparticles. The stereocomplex microparticles showed a continuous release of the interlocked peptide for a period of one to three months under physiological conditions. Various factors, including method of complex formation, molecular weight of PLA, leuprolide:polymer and d-PLA:l-PLA complex ratios, and additives, influenced the release pattern of leuprolide from the stereocomplexes. Continuous release of leuprolide for over 100 days was observed for certain stereocomplex compositions. In vivo evaluation of the leuprolide loaded stereocomplexes in rats by monitoring testosterone levels in the blood of rats after subcutaneous injection showed low testosterone levels for over 42 days.

Animals↗
PubMed1990

Clinical study of leuprolide depot formulation in the treatment of advanced prostate cancer. The Leuprolide Study Group.

In a phase III, open, multicenter study we evaluated the safety and efficacy of the depot formulation of leuprolide (7.5 mg. injected intramuscularly every 4 weeks) in patients with stage D2 prostate cancer who had not previously received systemic treatment. Serum testosterone, luteinizing hormone and plasma leuprolide levels were monitored during the 24-week study period. Median interval to onset of castrate testosterone levels was 21 days and mean testosterone levels decreased to within the castrate range by week 3 of treatment. After onset of castrate levels there were no escapes (defined as 2 consecutive values of greater than 50 ng./dl.) of testosterone levels during the 24 weeks. Suppression of testosterone did not differ significantly from that observed in patients receiving the daily subcutaneous injection of leuprolide acetate in the first 24 weeks of another study. Objective response (no progression) to treatment occurred in 81% of 53 evaluable patients and adverse (related and unrelated) events were reported in 45 of the 56 patients. The response rate and incidence of adverse events in this study did not differ significantly from those occurring with the daily formulation. We conclude that the depot formulation of leuprolide is safe and effective in the treatment of advanced prostatic cancer, and that the safety and efficacy of this formulation do not differ significantly from those of the daily subcutaneous formulation.

Aged↗
PubMed1989

Treatment of leiomyomata uteri with short-term leuprolide followed by leuprolide plus estrogen-progestin hormone replacement therapy for 2 years: a pilot study.

Five premenopausal women with leiomyomata uteri were treated with leuprolide for 3 months and demonstrated a reduction in mean uterine volume of 49%. Cyclic conjugated equine estrogens and MPA were added to leuprolide therapy during the ensuing 24 months, with no significant changes in mean uterine volume or peripheral bone density.

Bone and Bones↗
PubMed1990

Treatment of newly diagnosed state D2 prostate cancer with leuprolide and flutamide or leuprolide alone, phase III, intergroup study 0036.

In order to test the hypothesis of complete androgen blockade for advanced prostate cancer (D2CaP), an intergroup trial was instituted in 1985 comparing leuprolide (L) alone to the combination of L with flutamide (F). Eligibility requirements included previously untreated histologically confirmed stage D2CaP, measurable bone or soft tissue metastases, performance status (PS) of 3 or better, acceptable renal and hepatic function, no severe cardiac disease, and no prior or concomitant endocrine therapy. Stratification at entry was on the basis of PS and none or minimal disease (MD) versus severe degree (SD) of bone metastases. Six hundred and seventeen patients were entered into this study between March 1985 and April 1986. At the present time, there is a 3-month difference in the median progression-free survival (13.9 vs 16.9 months; P = 0.039) and a 7.1-month difference in survival (27.9 vs 35.01 months; P = 0.035) favoring L + F. In L + F-treated patients with good PS-MD, the median survival recently has been reached and is 51.9 months vs 39.6 months for L + P patients. The 107 black patients in the study had median survival of 26.4 months vs 33.3 months for whites. Discussions of racial differences in survival as well as other prognostic factors will be presented. The combination of L + F is superior to treatment with L alone. The benefits appear greatest in patients with minimal disease.

Antineoplastic Agents↗
PubMedDate not supplied

Chronic (60-week) toxicity study of DUROS leuprolide implants in dogs.

The toxicity and pharmacodynamics of leuprolide acetate delivered from subcutaneously implanted DUROS leuprolide implants were examined in sexually mature male beagle dogs. The DUROS leuprolide implant is a sterile, nonpyrogenic, nonerodible, single-use, implantable, osmotically driven, drug delivery system for the palliative treatment of advanced prostate cancer. It contains 65 mg of leuprolide and is designed to deliver leuprolide continuously at a nominal rate of 120 microg per day for at least 12 months. Serum drug and testosterone concentrations were compared to values from dogs receiving monthly intramuscular injections of Lupron Depot 3.75 mg or no treatment (sham-operated). The local tissue response induced by subcutaneously implanted DUROS leuprolide implants was also evaluated. Beagles were implanted with a DUROS leuprolide implant for 52 weeks followed by removal and implantation of a new DUROS leuprolide implant for an additional 8 weeks. No mortality or morbidity occurred in this study. No treatment-related changes occurred in mean body weights, blood chemistry, or hematology during the study. Treatment-related atrophy of the testes, epididymides, and prostate gland, consistent with the known pharmacological effects of the drug, was observed in all dogs receiving the DUROS leuprolide implant or the Lupron Depot. Histological examination of these organs showed no distinguishable difference between dogs treated with the DUROS leuprolide implant or Lupron Depot. Weekly serum samples from dogs with DUROS leuprolide implants indicated continuous leuprolide delivery over 60 weeks, while some samples from the Lupron Depot group fell below measurable concentrations. Analysis of serum samples collected every 28 days just before Lupron Depot injection showed that 80% of these samples had leuprolide concentrations below the limit of quantitation (0.1 ng/ml). Serum testosterone concentrations were below castrate levels (<50 ng/dl) by 4 weeks after implantation of DUROS leuprolide implant and remained so for the duration of the study. Lupron Depot 3.75 mg also effectively lowered serum testosterone concentrations, but required reinjection every 28 days. All local tissue reactions to the DUROS leuprolide implant at implant sites were classified as mild following macroscopic examination. Microscopic site scores were mild to moderate. The DUROS leuprolide implant was shown to be safe, to provide continuous leuprolide delivery, and to effectively lower serum testosterone concentrations below castrate levels.

Animals↗
PubMed1999

Prevention of rat mammary carcinoma utilizing leuprolide as an equivalent to oophorectomy.

A clinical trial is currently under way to examine the effectiveness of leuprolide as a breast cancer chemopreventive agent and contraceptive. This trial, as well as similar proposed studies, is based on the assumption that leuprolide is as effective as surgical castration in preventing the onset of mammary tumors; however, this has not been well documented in the DMBA animal model. We directly compared leuprolide and oophorectomy in this model and examined a combined therapy of leuprolide/bromocriptine. Twenty-seven day old female Sprague-Dawley rats were randomly allocated into one of eight groups. All rats received a 20-mg dose of DMBA at the age of 55 days. Group 1 (n = 10), no treatment; Group 2 (n = 9), leuprolide (100 microg/kg/day) for eight weeks beginning four weeks prior to DMBA; Group 3 (n = 10), oophorectomy four weeks prior to DMBA with replacement estrogen beginning four weeks following DMBA. Estrogen replacement was achieved with a 0.05-mg estradiol tablet releasing 0.833 microg/day over a 60-day period. Group 4 (n = 10), leuprolide (100 microg/kg/day) initiated two weeks prior to DMBA and continuing for two weeks following DMBA; Group 5 (n = 9), oophorectomy two weeks prior to DMBA with 0.05 mg of estradiol in depot form, releasing 0.833 microg/day, beginning four weeks following DMBA and continuing until week 16 of the study; Group 6 (n = 10), leuprolide (100 microg/kg/day) beginning two weeks prior to DMBA and continuing for the duration of the experiment; Group 7 (n = 10), leuprolide (100 microg/kg/day) for eight weeks beginning two weeks prior to DMBA; Group 8 (n = 9), leuprolide (100 microg/kg/day) and bromocriptine (83 microg/day) for eight weeks beginning two weeks prior to DMBA. At nineteen weeks (15 weeks post DMBA), animals were sacrificed and autopsies performed. One hundred percent of untreated animals developed tumors. No animals undergoing oophorectomy four weeks prior to DMBA or receiving leuprolide four weeks prior to and simultaneously with DMBA developed tumors. In animals pretreated two weeks prior to DMBA with leuprolide or oophorectomy, each group had one animal with tumor development. No tumors developed in the animals receiving ongoing injections of leuprolide. However, one tumor developed in those receiving leuprolide for the first eight weeks beginning two weeks prior to DMBA administration. One animal receiving both leuprolide and bromocriptine developed one tumor. We conclude that chemical oophorectomy (with leuprolide) is as effective as surgical oophorectomy in inhibiting DMBA induced carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1988

Leuprolide acetate: serum and follicular fluid concentrations and effects on human fertilization, embryo growth, and granulosa-lutein cell progesterone accumulation in vitro.

Data from various animal models have demonstrated significant extrapituitary effects of gonadotropin-releasing hormone agonists. The purpose of this study was to determine the effects of therapeutic concentrations of leuprolide acetate on human granulosa-lutein cell steroidogenesis, fertilization, and embryo growth rates in vitro. During leuprolide administration, mean serum concentrations of leuprolide were less than 50 ng/ml and were undetectable 48 hours after cessation of administration. There was no effect of leuprolide on progesterone (P) secretion by granulosa-lutein cells cultured in the presence or absence of human chorionic gonadotropin. The effect of leuprolide on embryo growth rates was evaluated with the mouse two-cell embryo culture model and a retrospective review of early embryo growth rates in humans receiving adjunctive leuprolide therapy. There was no measurable effect of leuprolide on early embryo growth in either species. These data indicate that (1) serum and follicular and peritoneal fluid concentrations are undetectable 2 days after discontinuation of leuprolide; (2) there is no measurable effect of leuprolide on human or murine embryo growth rates up to the 8 cell stage in vitro; and (3) there is no measurable effect of leuprolide on granulosa-lutein cell P accumulation.

Animals↗
PubMed1998

Comparison of goserelin and leuprolide in combined androgen blockade therapy.

OBJECTIVES: To perform exploratory analyses of data from a controlled trial that assessed the efficacy and tolerability of two antiandrogens, bicalutamide and flutamide, each combined with monthly depot preparations of leuprolide or goserelin, in patients with Stage D2 prostate cancer. One analysis compared goserelin plus antiandrogen therapy with leuprolide plus antiandrogen therapy; a second analysis compared the four combined androgen blockade (CAB) regimens. METHODS: This was a randomized, multicenter trial, open-label for luteinizing hormone releasing hormone analogue (LHRH-A) therapy, double-blind for antiandrogen therapy, with a two-by-two factorial design. Eight-hundred thirteen patients were allocated in a ratio of 2:1 to goserelin therapy (3.6 mg every 28 days) or leuprolide therapy (7.5 mg every 28 days) and 1:1 to bicalutamide therapy (50 mg once a day) or flutamide therapy (250 mg three times a day). The end points of time to progression and survival were assessed with a median of 160 weeks of follow-up. RESULTS: The percentages of progression events (70.9% versus 73.3%) and deaths (54.3% versus 56.8%) were similar for goserelin plus antiandrogen and leuprolide plus antiandrogen therapies. The hazard ratios for goserelin plus antiandrogen therapy to leuprolide plus antiandrogen therapy were 0.99 (95% confidence interval [CI] 0.84 to 1.18; P = 0.92) and 0.91 (95% CI 0.75 to 1.11; P = 0.34) for time to progression and survival, respectively. Goserelin plus antiandrogen and leuprolide plus antiandrogen therapies were generally well tolerated, and the side effects associated with depot administration occurred with a low frequency in the two groups. There were no significant differences among the goserelin plus bicalutamide, goserelin plus flutamide, or leuprolide plus bicalutamide therapy groups, but leuprolide plus flutamide therapy had a significantly poorer outcome than the other three therapies. The side-effect profiles for the four CAB groups were generally similar; diarrhea was more common among patients treated with flutamide and hematuria was more common among patients treated with bicalutamide. CONCLUSIONS: Although the results of these exploratory analyses should be interpreted with caution, they indicate that goserelin plus antiandrogen and leuprolide plus antiandrogen therapies are similarly well tolerated and have equivalent time to progression and survival, and that leuprolide plus flutamide therapy appears to be the least effective of the four CAB regimens.

Adult↗
PubMed1991

The gonadotropin-releasing hormone agonist leuprolide affects the thymus and other non-reproductive systems of female rats.

To evaluate the effects of a gonadotropin-releasing hormone agonist on non-reproductive systems, we administered [D-Leu6,Des-gly10]-GnRH ethylamide (leuprolide; 5 micrograms/day) for 21 days to female Sprague-Dawley rats. In Experiment 1, continuous infusion (Alzet minipumps sc) was compared to injection. Increased thymus and body weights and decreased estradiol and uterine weights were noted for both administration methods. Spleen weight increased only in rats treated by continuous infusion. Ovary, kidney and liver weights did not change. Only leuprolide-injected rats had elevated LH with decreased corticosterone and ACTH levels, possibly related to the injection process. Glucose, insulin, progesterone, FSH and corticosterone/ACTH were not different. In Experiment 2, intact and ovariectomized rats were implanted with minipumps delivering leuprolide or 0.9% NaCl. Body and thymus weights increased, whereas uterine weight and estradiol declined in both leuprolide-treated and ovariectomized rats. No synergism between leuprolide and ovariectomy was noted. Thymosin alpha 1, but not thymosin beta 4, increased in leuprolide-treated ovariectomized rats. Peripheral white blood cell count was elevated in leuprolide-treated intact rats and ovariectomized rats. In bone marrow, non-nucleated cell count declined in leuprolide-treated intact rats, contributing to the decreased total cell count in this group. Nucleated cell count was unaffected. Therefore, thymus weight gain was accompanied only in some cases by functional changes. Our results demonstrate that leuprolide affects non-reproductive systems, in a similar manner to ovariectomy. We suggest that such alterations may be due to the hypoestrogenic environment produced by leuprolide.

Adrenocorticotropic Hormone↗
PubMed2002

Serum luteinizing hormone rises within minutes after depot leuprolide injection: implications for monitoring therapy.

OBJECTIVE: To find the time of the serum gonadotropin peak after depot leuprolide injection in children and to show that depot leuprolide therapy can be monitored by measuring serum luteinizing hormone (LH) immediately after injections. STUDY DESIGN: We measured concentrations of leuprolide, LH, and follicle-stimulating hormone (FSH) at multiple time points before and after the first dose of depot leuprolide in 14 pubertal children beginning therapy. Gonadotropins and sex steroids were measured again after the fourth dose. RESULTS: Serum leuprolide, LH, and FSH levels rose rapidly after initial injection, reaching sustained elevations at 30 to 120 minutes. The median LH level increased from 2.1 mIU/mL at baseline to a peak of 27.5 mIU/mL at 45 minutes, and FSH increased from 5.2 to 16.5 mIU/mL. After 3 months on therapy, median serum LH after depot leuprolide injection was only 0.83 mIU/mL, similar to levels observed after intravenous or subcutaneous gonadotropin-releasing hormone stimulation in comparable subjects on depot leuprolide. CONCLUSION: Our pharmacokinetic data demonstrate that free leuprolide present in a depot leuprolide injection is equivalent to gonadotropin-releasing hormone in stimulating a rapid rise in serum gonadotropin concentrations. We propose that a single serum sample for LH obtained 30 to 60 minutes after depot leuprolide injection in children provides a convenient and accurate assessment of treatment efficacy.

Adolescent↗
PubMed2000

Estradiol suppression and recovery during leuprolide acetate treatment in women as determined weekly by an ultrasensitive recombinant cell bioassay.

We studied the time frame of suppression and recovery of estradiol after injection with leuprolide acetate utilizing an ultrasensitive recombinant cell bioassay for estradiol in eight normal premenopausal women. Previous studies have shown suppression of gonadotropins and estradiol at 4 weeks after the depot injection, but no studies have shown the weekly time course of estradiol suppression or recovery. Four women received one 3.75 mg i.m. injection of leuprolide acetate and four received two 3.75 mg doses of leuprolide acetate 4 weeks apart. Estradiol, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels were measured weekly for 8 to 12 weeks. Estradiol was significantly suppressed to 26.6 +/- 19.3% of baseline values by week 3 after the initial dose of leuprolide acetate and suppressed to 2.7 +/- 3.1% of baseline values by week 4 (p < 0.01 versus baseline). The actual values were less than 14.7 pmol/l (4 pg/ml) in all women by week 4. Estradiol remained suppressed for 8 weeks after one dose of leuprolide acetate and remained suppressed for 6 weeks after a second dose administered 4 weeks later. LH and FSH followed a similar pattern, but only remained suppressed for 7 weeks after one dose of leuprolide acetate and for 6 weeks after two doses. Estradiol levels at baseline were significantly correlated with body mass index (BMI). We also studied one postmenopausal woman. Her baseline estradiol levels were 10.3 pmol/l (2.8 pg/ml) and were suppressed to 3.9 pmol/l (1.1 pg/ml) by 2 weeks after leuprolide acetate. In conclusion, estradiol was suppressed to postmenopausal levels by the end of the first month of treatment with leuprolide acetate, as determined by an ultrasensitive bioassay. Higher doses would need to be tested to determine whether greater suppression can be achieved. The hypothalamic-pituitary-gonadal axis begins to recover 7 weeks after one dose and 6 weeks after a second dose of leuprolide acetate. This confirms the adequacy of 4-week dosing to maintain estradiol and gonadotropin suppression in adult women treated with leuprolide acetate, but raises the question whether less frequent dosing may be possible in some situations, or whether higher doses may be needed in some situations for an even greater degree of estradiol suppression.

Adult↗
PubMed1993

Prevention of hypermenorrhea with leuprolide in premenopausal women undergoing bone marrow transplantation.

We report on the use of leuprolide to prevent heavy menstrual bleeding that often occurs before platelet engraftment in premenopausal women undergoing bone marrow transplantation (BMT). Leuprolide, a synthetic analog of gonadotropin-releasing hormone (Gn-RH-a), was given to 34 patients by intravenous bolus injection, 1 mg daily, until platelet recovery. The median duration of therapy was 50 days (range 16-170). When necessary, patients self-administered the drug after discharge from the hospital. No adverse effects could be related directly to the use of leuprolide. Leuprolide effectively prevented menstruation in 25 patients (73%), failed in seven (21%), and two patients were not evaluable. The success of leuprolide therapy was related to the time of onset of treatment, as anticipated from the gradual effect of Gn-RH-a on the menstrual cycle. The failure rate was only 6% (one of 16 patients) when leuprolide was started at least 2 weeks prior to the development of thrombocytopenia, compared to a failure rate of 33% (six of 18 patients) when leuprolide was started at a later time. We conclude that leuprolide as a single agent is a safe and effective method to prevent menstrual bleeding during BMT. Additional studies are needed to determine the best timing for the onset of therapy and the relative benefit of leuprolide compared to other prophylactic approaches in patients with lengthy thrombocytopenia.

Adolescent↗
PubMed1999

Permeability and absorption of leuprolide from various intestinal regions in rabbits and rats.

The in vitro permeability and in vivo absorption of leuprolide in different intestinal regions were measured to investigate the feasibility for site-specific delivery of leuprolide in the gastrointestinal (GI) tract. In vitro permeability of leuprolide in the rabbit GI tract was performed using a side-by-side diffusion apparatus and the permeability coefficients in the jejunum, ileum and colon were 0.27x10(-7), 2.96x10(-7) and 7.85x10(-7)cm/s, respectively. Varying the donor drug concentrations from 2 to 10 mg/ml, the permeability coefficients were independent of the donor concentration, suggesting the transport mechanism of passive diffusion. Using an intestine loop model in anesthetized rats, bioavailabilities of leuprolide in the jejunum, ileum and colon were 1.28, 5.62 and 9.59%, respectively. Drug recovery from the loop 5 h after dosing was 10.7% in jejunum, 24.5% in ileum and 40.7% in colon. Additional in vivo studies using conscious rats showed that the bioavailability of leuprolide was less than 1% for both ileal and colonic administration. In vivo absorption of leuprolide from ileum was not significantly different from colon in conscious rats. Sodium salicylate, a permeation enhancer, was co-administered with leuprolide to the rat ascending colon, and results showed a 4-fold increase in the bioavailability in conscious rats. Thus, in vivo studies indicate that both absorption and enzymatic degradation of leuprolide in the GI tract is site-dependent and the lower intestine may be an advantageous region for oral delivery of leuprolide.

Animals↗
PubMed2005

[Mechanisms of action of transportation of liposomes and chitosan-coated liposomes containing leuprolide across intestine and Caco-2 cell].

AIM: To investigate the mechanisms of action of transportation of liposomes and chitosan-coated liposomes containing leuprolide across rat intestine and Caco-2 cell. METHODS: Everted-gut technique and Caco-2 cell were used to study the transport properties of free leuprolide, liposomes and chitosan-coated liposomes containing leuprolide. Caco-2 cell was used to study the effect of chitosan concentration and the order of addition on the permeation of liposomes. RESULTS: The transport of leuprolide was passive diffusion. Probably because the entrapment by liposomes prevents the transport of leuprolide across the rat intestine and Caco-2 cell, the permeation amount of leuprolide from liposomes was lower than that of the free drug. However, liposomes protected the leuprolide from degradation. Chitosan promoted the transport of leuprolide from liposomes and there was no obvious difference in enhancement effect from the concentration of 0.1% to 0.5%. On the other hand, the incubation of chitosan with liposomes may weak the enhancement effect of chitosan. CONCLUSION: Chitosan-coated liposomes showed both protection and enhancement effect, therefore, they may promote the oral absorption of leuprolide.

Animals↗