Evaluation of subdermal biodegradable implants incorporating rifampicin as a method of drug delivery in experimental tuberculosis of guinea pigs.

Conventional chemotherapy of tuberculosis and leprosy requires rifampicin to be administered orally. The long period of treatment and adverse side effects of the drug lead to poor compliance. To overcome this, subdermal implants incorporating rifampicin in pure and micro-encapsulated forms with biodegradable material were used as a new drug delivery system in experimental tuberculosis of guinea pigs. Two experiments were performed with 45-mg and 100-mg drug implants. Progress of infection was followed at intervals by studying necropsy scores and weights of the organs of predilection and levels of the drug in the blood were determined. There was a constant and sustained release of the drug in therapeutic concentrations for 30 and 50 days until the implants were completely assimilated without causing any damage to the implant site. The importance of multiple implants at long intervals is discussed.

Saponins from Deutzia corymbosa.

Two new saponins were isolated from Deutzia corymbosa and characterized as: echinocystic acid-3-O-[alpha-L-arabinopyranosyl(1----4)]alpha-L- arabinopyranoside and echinocystic acid-3-O-[beta-D-galactopyranosyl(1----4)alpha-L- rhamnopyranosyl(1----4)]alpha-L-arabinopyranoside. Umbellferone and sitosterol-beta-D-glucoside were also isolated and characterized.

Isaptent--a new cervical dilator.

A new cervical dilator, Isaptent, was prepared from granulated Plantago ovata (Isapgol) seed husk. It was evaluated in a multicentric clinical trial for dilatation of the cervix in subjects opting for medical termination of pregnancy. The trial covered 804 women in over 21 centres in different parts of the country. The cases were between 15 to 45 years of age, 0 to 10 parity with a gestation period of 8 to 24 weeks. A single tent was used in 750 subjects and satisfactory dilatation was achieved in 94% of the cases. The cervical dilatation bore no relationship to age, parity and gestation period of the subjects. The tent provided self-lubrication, caused no apparent damage to the cervix and the vaginal flora remained unchanged in the randomly selected subjects in whom bacteriologic studies were performed. The outcome of the clinical trial and advantages of Isaptent over the other procedures used for cervical dilatation are discussed.

Screening of Indian plants for biological activity: Part VII--Spermicidal activity of Indian plants.

PIP: Extracts of about 1600 Indian plants were tested for spermicidal activity. A small quantity of rat vasal or epididymal contents was placed on 2 drops of plant solution, mixed, and examined under a phase contrast microscope. Results were scored positive if 100% of spermatozoa became immotile. Tests were repeated 3 times. and sperm revival tested by addition of buffer to the immobilized sperm sample. Plant extracts showing positive activity were tested on liquified human semen. 30 plants showed spermicidal activity in rats, of which 16 caused instantaneous immobilization of human spermatozoa. Studies are underway on the isolation of active constituents and subsequent structural relationships.^ieng

Constitution of scheffleroside: a spermicidal saponin from Schefflera capitata.

PIP: While screening Indian plants for biological activities, it was observed that a 2% aqueous solution of the crude 70% aqueous ethanolic extract of Schefflera capitata showed significant activity against both rat and human spermatozoa. The new saponin, melting point 230-232 degrees, gives on acid hydrolysis D(+)-fucose (1 mole), D(+)-galactose (1 mole), D(+)-glucoronic acid (1 mole) and echinocystic acid (1 mole). Its structure has been tentatively assigned to scheffleroside.^ieng

Postcoital contraceptive efficacy and hormonal profile of Lepidium capitatum.

PIP: Hexane soluble fraction of the Lepidium captiatum plant collected in Himachal Pradesh, India, was administered orally to colony bred albino mice, rats, and golden hamsters to test the plant's postcoital antifertility efficacy and estrogenic and antiestrogenic activities. 2.5 kg of the whole air-dried and powdered plant was extracted 4 times with 90% ethanol, which was evaporated under reduced pressure. The resultant aqueous suspension was partitioned 3 times with hexane and concentrated under vacuum to achieve the hexane soluble and hexane insoluble fractions. Oral administration of 250 mg/kg of crude ethanolic extract of the whole plant on postcoital days 1-5 prevented pregnancy in about 77% of mated female rats. The hexane soluble fraction inhibited pregnancy in 100% of the rats at a dose of 250 mg/kg and in 50% at 125 mg/kg. In comparison to controls, there was a significant reduction in implantation number at both 125 mg/kg and 625 mg/kg doses. The extract failed to prevent pregnancy in hamsters even at a daily dose of 500 mg/kg on postcoital days 1-5. No contraceptive efficacy of the hexane insoluble extract was observed in rats or hamsters. The extract exhibited potent estrogenic activity at the contraceptive dose, without antiestrogenic activity. A significant uterotrophic effect was seen even at 1/40 of the contraceptive dose. When administered orally for 3 consecutive days, the hexane soluble fraction induced normal implantations at 250 mg/kg and lower doses in adult female mice undergoing experimentally induced delayed implantation. The maximum response in terms of the percentage of pregnant animals and the average number of implantations was observed at 125 mg/kg dose. The experimental results confirm the frank estrogenicity of the extract.^ieng

Isaptent--a new aid for cervical dilatation.

PIP: Past research has shown that the method of cervical dilatation is more important in preventing immediate and delayed complications of abortion morbidity than the method of uterine evacuation. An improved method of cervical dilatation has been developed at the Central Drug Research Institute in Lucknow, India. The device, the Isaptent, is a simple and cheap method of insuring a gradual, atraumatic and predictable dilatation of the cervix. Tests of the device with 460 abortions showed its success, which was not associated with the age, parity, or gestation period of the patient. The tent provided selflubrication and caused no damage to the cervix. The advantages of the Isaptent over currently-used methods--metallic instruments, laminaria tents, or prostaglandins--are summarized.^ieng