VAginal Material

Urine specimens usually are examined for the eggs of Schistosoma haemotobium or the trophozoites of Trichomonas vaginalis, although occasionally the larvae of Strongyloides stercoralis may be found in patients with hyperinfection syndrome. Urine is the usual specimen for the diagnosis of Trichomonas infection in males. See below (Vaginal Material) for culture method. Urine is centrifuged, and the sediment is examined microscopically. 

Vaginal material is best submitted as liquid in a tube, although swabs submitted in a small amount of saline may be used. A drop of the material is covered with a cover slip and examined with reduced light. To culture, 1 or 2 drops of urine sediment or vaginal exudate are inoculated into tubes of warmed, modified Diamond medium. If vaginal swabs are submitted, the swab is immersed in the medium and pressed against the side of the tube to express material. Tubes are incubated at 35°C, and drops of culture are examined by wet mount at 48 and 72 h for motile trophozoites. 

---

In the last several decades, physical properties of vaginal contraceptive formulations have been improved to deUver spermicide more effectively and enhance consumer compliance. The formulation that deUvers the spermicide can affect the efficacy of vaginal contraceptives (86,87). Formulations currentiy available include jeUies, creams, suppositories, aerosol foams, and foaming tablets. Each consists of a relative inert base material that serves as a carrier for the chemically active spermicide and blocks to some extent the passage of sperm. 

Vaginal Administration. Though not a common one, some materials do have routine exposure by this route (spermicides, tampons, douches, and antibiotics, for example), and, therefore, must be evaluated for irritation and toxicity by this route. The older preferred models used rabbits and monkeys (Eckstein et al., 1969), but, more recently, a model that uses rats has been developed (Staab et al., 1987). McConnell (1973) clearly described the limitations, particularly of volume of test material, involved in such tests. 

A new class of water-soluble materials [10,11], was developed as a result of such design parameters that will be referred to as double substituted cationic cellulose ethers (DCEs). These materials contain both a cationic substituent and a hydrophobic substituent, attached to a cellulose ether backbone. The use of a double-substituted hydrophobe modified cationic polysaccharide is fundamentally different from current commercial vaginal formulations, which rely exclusively on nonionic or anionic vehicles. 

A host of bioadhesive controlled release systems have been proposed in recent years. Among the most commonly studied applications of bioadhesive materials is the area of buccal controlled delivery [408], The buccal delivery of small peptides from bioadhesive polymers was studied by Bodde and coworkers [409], and a wide range of compositions based on poly(butyl acrylate) and/or poly(acrylic acid) gave satisfactory performance. Bioadhesive poly(acrylic add)-based formulations have also been used for oral applications [402,410] for the sustained delivery of chlorothiazide [410] and for a thin bioadhesive patch for treatment of gingivitis and periodontal disease [411]. Other bioadhesive applications of polyelectrolytes include materials for ophthalmic vehicles [412,413], and systems for oral [410,414,415-419], rectal [420,421] vaginal [422] and nasal [423] drug delivery. 

Since the invasive form of Candida in vaginal mycosis is the pseudo-mycelium, we also looked at this morphologically specialized material. We observed that bifonazole causes an accumulation of dihydrolanosterol exclusively, whereas clotrimazole causes the normal accumulation of 24-methylenedihydrolanosterol, dihydrolanosterol, and lanosterol (Figure 18). However, after bifonazole application, the rate of total sterol synthesis is lowered by a factor of two, a result which will be discussed later. 

Typical vaginal delivery systems such as foams, gels and tablets are removed in a relatively short period of time by the self-cleansing action of the vaginal tract. In the eye, materials are diluted by tears and removed via the lachrymal drainage system. 

A topical powder product may be marketed in a sifter-top container made of flexible plastic tubes or as part of a sterile dressing (e.g., antibacterial product). The topical formulations in a collapsible tube can be constructed from low-density polyethylene (LDPE), with or without a laminated material. Normally, there is no product contact with the cap during storage. Thus usually there is no cap liner, especially in collapsible polypropylene screw caps. Normally separate applicator devices are made from LDPE. Product contact is possible if the applicator is part of the closure, and therefore an applicator s compatibility with the drug product should be established, as appropriate (e.g., vaginal applicators). 

Topical dosage forms such as creams, emulsions, gels, lotions, ointments, pastes, and powders may be marketed in plastic materials. Topical dosage formulations are for local (not systemic) effect and are generally applied to the skin or oral mucosal surfaces. Some vaginal and rectal creams and nasal, otic, and ophthalmic solutions may be considered for topical drug products. 

Besides poly(dimethylsiloxane), other elastomeric polymers have been employed in the manufacturing of vaginal rings, such as poly(dimethylsiloxane/vinylmethylsi-loxane), styrene-butadiene-styrene block copolymer, and poly(ethylene-co-vinyl acetate) [123-125], In fact, poly(ethylene-co-vinyl acetate) (commonly referred as EVA) appeared in the mid 1990s as an alternative to poly(dimethylsiloxane), when the manufacturer of this last material stopped supplying it for human use, demonstrating it to be very suitable for the production of controlled-release systems. 

Samples. Primate sera were obtained from the Yerkes Primate Center (Atlanta, GA). Human milk, saliva, and urine were obtained from donors and frozen at —70 °C within 15 min of receipt. Vaginal secretions were obtained on sterile swabs during routine pelvic examinations. Human kidney, liver, and pancreas were obtained from cadavers within 6 h of death and homogenized in carbonate-bicarbonate buffer (pH 9.2) in a Precision Scientific tissue homogenizer. The homogenates were centrifuged for 10 min at 500 X g to pellet particulate material, and the soluble proteins were precipitated with cold acetone at a 10 1 ratio. A pellet of the precipitated proteins was obtained after 10 min of centrifugation at 500 X g and was resuspended in carbonate-bicarbonate buffer. 

---