Vaginal solutions

Preparation, Release Control and Quality Requirements of Vaginal Solutions. 224... 

Vaginal pessaries resemble rectal suppositories in many aspects. Differences from rectal suppositories are discussed. Vaginal solutions are mentioned briefly. They are not frequently used and largely resemble irrigation solutions and solutions for cutaneous use. 

Suppositories Enemas Pessaries Vaginal solutions Biopharmaceutics Formulation Preparation Hard fat Content uniformity... 

Vaginal solutions, emulsions and suspensions Tablets for vaginal solutions and suspensions Semisolid vaginal preparations (ointments, creams, gels)... 

Vaginal solutions usually contain active substances dissolved in water and are intended for a local effect. The Ph. Eur. describes solutions as well as emulsions and suspensions. Only solutions are seen in pharmacy practice and just occasionally such as lactic acid solutions, with or without sodium lactate, iodinated povidone (povidone-iodine) solutions and chlorhexidine digluconate solutions. Accordingly, this chapter discusses the solutions only. Solutions may be prepared either ready-for-use, or as a concentrate to be diluted before use, or as a tablet to be dissolved in water shortly before use. 

The volume of a vaginal solution varies from 150 to 200 mL. A concentrate for dilution will be diluted by the patient about ten times, depending on the filling marks of the available irrigator. 

When the physiological pH of the vagina (pH = 3.5-4.5) is not maintained the microbiological balance in the vagina may become disturbed. Therefore the solution should have a physiological pH. Especially when the vaginal solution is intended for correction or support of the pH, for instance a lactic acid solution, a buffered solution is preferred. 

Excipients are added to make a vaginal solution iso-osmotic. Iso-osmosis is especially important for solutions used on a damaged mucosa or after operations. Frequently sodium chloride is added for iso-osmosis. Glycine is used as an... 

Just as in enemas (see Sect. 11.9.6) chemical stability may be a problem in vaginal solutions. This caimotbe avoided by choosing a different pH or another solvent as with enemas. So the active substance should be inherently stable in water. For the microbiological stabiUty of non-sterile vaginal solutions which are often concentrates for multiple dosing, preservation may be necessary if the concentrate doesn t meet the test on preservation effectiveness (see Sect. 32.8). Methyl parahydroxybenzoate can be used as a preservative. 

A vaginal solution with iodinated povidone is best delivered as a stable concentrate, for instance Betadine -solution 100 mg/mL. The patient should dilute the concentrate ten times in an irrigator. The indication is fluor vaginalis with clinically evident inflammation but without a microbiological diagnosis. 

A bacterial vaginosis during pregnancy can also be treated short term with an iodinated povidone vaginal solution. 

Non-sterile but preserved vaginal solutions may have a shelf life of 3 years after preparatiOTi, if prepared according to a standard formula and chemically and physically stable. Once opened by the patient, such vaginal solutions can be assigned an in-use period of 6 months. A concentrate diluted by the patient should be kept only 24 h after dilution. A non-standardised preserved preparatirai should not be stored in the pharmacy because the maximal shelf Ufe of say 1 month, may be reasonably needed by the patient. A diluted concentrate may be kept for 24 h after dilution. Unpreserved n(Mi-sterile vaginal solutions may have a shelf life of maximal 2 weeks and they have to be stored in a refrigerator. 

Sterile vaginal solutions are packaged in a single-dose container that can be sterilised, for instance glass (preferably class I, eventually class II) or plastic (polypropylene). Preserved concentrates, intended to be diluted before use, are usually packaged in a container of glass (class III) or plastic (polypropylene, polyethylene) meant for multiple dosing. 

Method of preparation, release control and quality requirements of sterile vaginal solutions are the same as for irrigation solutions (Preparations for irrigation Ph. Eur., see Sect. 14.7). Preparation method and release controls of non-sterile vaginal solutions are the same as for solutions for cutaneous use (see Sect. 12.6.5). 

Eye lotions (irrigations for the eye) are discussed in Sect. 10.6.2. Vaginal solutions that don t need to be sterile are discussed in Sect. 11.12. Whole bowel irrigations are used before diagnostic examination. Those solutions for oral or rectal use are not described in this chapter. 

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