**8. Conclusion**

At least 10 reverse transcriptase inhibitors and 16 entry inhibitors have been or are in the process of being investigated in clinical or preclinical trials. Ideally, these compounds are characterized by high potency, low absorption from the vagina to the blood to minimize development of resistance, and have a long half-life in order to remain active over a long period. Tenofovir has also been formulated as a topical vaginally applied gel and assessed for its protective effect against Simian immunodeficiency virus (SIV) in macaques. The results indicated that the macaques receiving the tenofovir gel were completely protected from infection [117] and in human trials [118]. The results of the human trial were released in July 2010 and showed that use of the gel reduced acquisition of HIV infection by 39% overall, and

Topical microbicides are grouped into five classes of agents, based on their mode and site of

**Countries of clinical**

Kenya, Cameroon

Malawi; South Africa; Hlabisa, South Africa; Zambia; Zimbabwe;

Benin, India, Uganda, South Africa

**trial**

Ghana,

USA

Tenofovir 2010 [126-128] South Africa, Uganda,

USA, Kenya

Zimbabwe

1.Nonoxynol-9 (N9) 1985

2. C31G(cetylbetaine and myristamine oxide)1997 [121] 3. Sodium lauryl sulphate (Invisible Condom)2002 [122]

BufferGel, PRO 2000 Gel [123]

CMPD167, Maraviroc (MVC), cyanovirin-N, Cellulose sulphate, SPL7013.2010

Praneem 2005 [129] Basant India

[120]

[124,125]

by 54% in women who were highly adherent to gel use [118].

14 Trends in Basic and Therapeutic Options in HIV Infection - Towards a Functional Cure

**Microbicides type Mechanism Formulation and year**

Virucidal action through disrupting the viral envelope

Enhance the natural protective mechanisms within the vaginal canal through altered pH range

Negative charge, anionic polymers interact with HIV's viral envelope proteins and interfere with the attachment and fusion of HIV to target cell

Prevention of replication and release through inhibition of the

Combination of extracts prepared from plants with anti-retroviral properties of unknown

virus-encoded reverse transcriptase (RT) or integrase

(IN)

**Table 3.** Microbicides and their mechanism of action

mechanism

action [119] (Table 3)

Surfactants/membrane disruptors-based microbicides

**microbicides**

**host cell**

**Microbicide based on inhibition of HIV entry in the**

**Microbicides that act after entry of HIV in the host cells**

**Microbicides based on inhibitors with unknown mechanism of action**

**Vaginal milieu protector based**

HIV is widely distributed globally. Strong effort and interpersonal encouragement should be channeled on exploring and developing bioresources with antiretroviral potential to serve as a springboard for cheaper and locally available HIV drugs in addition to developing appro‐ priate bioprospecting policies. Behavioural change and abstinence remain a sure means of HIV prevention, but need to be complemented with additional biomedical options especially in the populations most vulnerable to HIV infection.
